Proper diagnosis of the dental-trauma patient must be done in a quick and accurate fashion. It involves a systematic approach to the evaluation of the patient. If not done systematically, attention is first paid to the most obvious injury and other injuries are often not initially identified.
The force or impact that caused injury to the teeth or mouth is often severe enough to cause concomitant injuries to the surrounding structures, head, brain, neck, chest, or abdomen. Sometimes the obvious injury is to the teeth and the patient is immediately brought to the dentist. Subtle injuries to other systems may become obvious during dental treatment. For example, a victim of a motor-vehicle accident is thrown forward against the dashboard, displacing the victim's anterior teeth, while also being restrained by a seat belt, causing slow bleeding of the spleen that causes abdominal pain while in the dental office.
This course will review all aspects of dental-trauma that might be encountered by a general dentist, dental specialist, or dental assistant. The diagnosis and treatment of injuries to the teeth, jaws, temporomandibular- joints, and soft tissues are covered in detail. The diagnosis of fractures of the bones of the jaws and face is included so that all dentists treating trauma can identify these injuries and make appropriate surgical referrals.
Figure 1: Dental injuries range from a single tooth to complex injuries of the teeth, bone and soft tissues. Thorough extraoral, intraoral, and radiographic examination is needed
A thorough history and examination are necessary of the patient who has suffered dental-trauma. Findings should be documented in the records, for clinical reasons and for the fact that many injuries result in litigation against the individual responsible for the injury.
A detailed history is important when the patient is first seen after an injury. Questions should be asked to determine the cause of the injury, symptoms, possibility of concomitant injuries, and the medical history of the patient before an accurate diagnosis and treatment plan can be established. Some of the questions that should be answered include:
|When did the injury occur?
||Where did the injury occur?
||How did the injury occur?
||Has there been any previous medical or dental treatment for this injury?
|Was there any loss of consciousness at the time of the injury? If so, for how long?
||Can you remember what happened before and after the injury?
||Do you have a headache?
||Do you have nausea?
||Have you been vomiting?
||Do you have double vision?
||Do you have any injuries to other parts of the body from this accident?
||Review medical history for serious illnesses, medications taken, and allergies.
||Have you been vaccinated against tetanus? When?
|Have the teeth been previously injured? When? Treatment performed? Treated by whom?
||Do you have pain? Where?
||Is there pain when biting teeth together?
||Is there pain to heat, or to cold air or water?
||Is there pain when opening or closing the mouth?
||Are any teeth loose?
||Does your bite feel normal? If not, why?
||If a tooth was completely avulsed:
||Where was the tooth found?
||When was it found?
||How long has it been out of the mouth?
||Was there dirt or debris on the tooth?
||How was the tooth stored?
||Was the tooth reimplanted? When? By whom? How long after the accident?
||If so, how was it stored prior to reimplantation?
||Was tetanus toxoid given?
||Were antibiotics given?
The clinical examination generally starts with an overall evaluation of the patient, working towards examination of the specific injury. This is particularly important when evaluating children, since any pain caused by examination of the injured area may upset them and prevent further examination.
While taking the history, the overall physical and mental state of the patient and the state of consciousness should be evaluated to assess the possibility of other injuries.
An extraoral examination should be performed to evaluate injuries to the face and surrounding regions. Visual extraoral examination is performed first to identify any bleeding, abrasions, contusions, lacerations, swelling, or subconjunctival hemorrhage of the eyes (indicative of a nasal or zygomatic fracture). Is there any bleeding or cerebrospinal rhinorrhea from the nose? Is there bleeding from or bruising around the external auditory canal? Are there any limited movements of the eyes?
Next, extraoral palpation of the infraorbital rims, nose, zygoma, zygomatic arch, maxilla, and mandible is performed, evaluating for pain, crepitus, displacement, or mobility. The temporomandibular-joints are palpated while the patient opens and closes the mouth, feeling for the lateral pole of the head of the condyle and any changes or deviation of translation movements. Any deviation of the midline of the chin can be observed at the same time.
With good light and good visualization, the oral cavity is examined for injuries. This can sometimes be difficult because of bleeding or limited opening of the mouth.
Soft tissue is visually examined for lacerations, ecchymosis, or swelling. Any lacerations should be explored to make sure they do not contain fragments of teeth, bone, glass, dirt, grass, or other foreign material. This exploration can be performed after the wound is anesthesized in preparation for closure. Examination prior to this would not be thorough due to pain.
The integrity of the dental arch is assessed. Bimanual palpation of the alveolar processes and mandible is performed to rule out maxillary, mandibular, or alveolar-process fractures. The occlusion should be checked.
The teeth are then evaluated for fractures, displacement, or other injuries. Mobility testing, percussion, and pulpal sensitivity testing should be performed when possible.
Mobility testing determines the degree of loosening of individual teeth or, in the case of alveolar fractures, several teeth. The degree of mobility is an aid in determining the type of displacement injury and is recorded on a scale of 1 to 3:
No mobility = 0
0 to 1 mm of horizontal mobility = 1
Greater than 1 mm of horizontal mobility = 2
Axial mobility = 3
A mobility of 0 can indicate no injury, an intrusion injury, or, in the case of postoperative examination, ankylosis. Percussion testing can be used to determine between these.
Percussion testing with the handle of an examination mirror or other metal handled instrument is used to determine tenderness to percussion and the tone of percussion. Tenderness to percussion occurs when there has been injury to the periodontal ligament. Percussion tone of a tooth with an intact periodontal ligament will be a low, dull sound. Percussion of a tooth that is intruded or locked into bone will produce a high, metallic tone. A tooth that has developed ankylosis will also produce a high, metallic tone.
Pulp-sensitivity testing, including cold and electric-pulp tests, should be performed when possible to establish the condition of the neurovascular supply to the injured teeth. While initial results may be inconclusive, they establish a baseline that can be compared with follow-up examinations in subsequent months. Repeat mobility and percussion testing, along with evaluation of tooth color, development of swelling or fistulas, and radiographic changes, can help determine the long-term health and status of the pulp.
electric-pulp testing, placement of the electrode on the incisal edge of the enamel, or in the case
of crown fractures on the most incisal edge of enamel, produces the most reliable results. Teeth
with incomplete root formation and open apices respond inconsis
The Dental-Trauma Patient
tently to electric-pulp testing, and testing primary teeth often is inconclusive because of patient cooperation.
After an initial clinical diagnosis is made, appropriate radiographs are taken to further evaluate injuries.
With injuries to teeth, periapical radiographs are the most useful to look for root or crown fractures, displacement, and damage around the periodontal ligament. They are also useful as a baseline to watch for later changes of the root and pulp.
Standard occlusal radiographs are at times useful to check the integrity of the arch and to look for tooth or alveolar injuries. Occlusal films can be used for lateral views of the anterior maxilla.
Panoramic radiographs are useful to evaluate injuries or fractures of the mandible, maxilla, and alveolar processes. They are by far the best screening radiographs for these injuries, as they are able to show injuries from the heads of the condyles to the symphysis.
For fractures of the mandible, other views are useful, including a PA skull, oblique view of the mandible, and Towne's view. For fractures of the maxilla, Water's views are used. For more complex maxillary and midface fractures, CT scans are useful.
The least serious injuries to teeth are concussion or subluxation. A traumatic impact to a tooth may cause a concussion or subluxation of the tooth without fractures or displacement of the tooth or alveolus. Hemorrhage and edema within the periodontal ligament space and edema in the pulp may occur. The periodontal ligament remains intact with a concussion and, therefore, there is no mobility of the tooth. With subluxation, the periodontal ligament is torn and the tooth loosened.
Clinical examination shows considerable sensitivity to both vertical and horizontal percussion. Bleeding from the gingival sulcus is generally not present. Initially, both electric and cold vitality testing may show no response. No radiographic findings are present with either concussion or subluxation. With concussion, the tooth is attached normally to its alveolar socket. With subluxation, the tooth is loosened in its socket, although it is not displaced.
With both, swelling in the periodontal ligament space will cause the tooth to be in hyperocclusion, leading to the patient complaint that the tooth is uncomfortable or painful to biting pressure.
|Figure 2: Example of fractures of the enamel and dentin, along with pulpal exposure. Note the mucosal laceration contains the missing fragments of teeth.|
The immediate treatment for both concussion and subluxation injuries involves treating the hyperocclusion caused by the edema and hemorrhage in the periodontal ligament. This is done by selective adjustment of the opposing teeth so that the injured tooth will not continue to be traumatized while the edema is resolving. The patient is also advised to not occlude on or traumatize this tooth during healing.
Splinting of tooth with a subluxation injury is usually not necessary. If necessary for patient comfort, the injured tooth may be splinted with an acid-etched resin splint to the adjacent teeth for 2 weeks.
After initial healing, the tooth should be monitored at 1, 3, 6, and 12 months post-injury for signs of pulpal necrosis or root resorption, although these are rare. Clinical, vitality, and radiographic examinations are performed at these visits.
The most common traumatic injury to adult dentition is a fracture of the crown of a tooth. A blow to the front of a tooth that exceeds the strength of the enamel or of the enamel and dentin will cause a fracture. Slips and falls, contact sports, vehicle accidents, and injuries from work tools are common causes.
Fractures may be vertical, horizontal, angle mesial or distal, or may be in a coronal plane involving the entire lingual or facial surface. The fractured segment may be dislodged, or the fracture can be incomplete with a fissure but no loss of tooth structure.
The amount of force required to fracture enamel or dentin is enough to also cause concussion, subluxation, or displacement of the injured tooth. These may affect the health of the pulp, even when there is not a pulpal exposure.
A fracture that involves only enamel will often initially cause discomfort to the patient due to the concussive injury that is often present. Mesioincisal and distoincisal angles of an anterior tooth are the most common locations for complete fractures of the enamel. The patient may also complain of sharpness to the tongue or lips if the fracture is complete with a segment missing.
Incomplete fractures may be difficult to diagnose and may be vertical, horizontal, or angled. A light beam directed parallel to the long axis of the tooth may help visualize the fracture.
Immediate treatment for enamel-only fractures is aimed at providing relief of the sharpness for the patient by smoothing any rough edges with a water-cooled high-speed diamond. Teeth with incomplete or complete fractures have been traumatized and should be taken out of occlusion with a diamond by adjusting the opposing occlusion.
Several weeks after the injury, definitive repair of the tooth can be performed. If a small portion of enamel is missing, the tooth can be recontoured by selective grinding with a diamond in a high-speed handpiece. If it is larger, an acid-etched composite restoration can be performed at this time.
All complete and incomplete fractures of enamel should be monitored for evidence of pulpal necrosis. Clinical, vitality, and radiographic examinations should be made at 1, 3, 6, and 12 months. After that, the tooth should be examined annually.
Fractures that extend through the enamel and dentin cause the patient sensitivity to temperature or to chewing due to the exposed dentin. Concussive injury may also be present, causing symptoms. Such fractures may expose the pulp to oral bacteria via open dentinal tubules between the dentin and pulp.
Immediate treatment is to protect the exposed dentin without causing further damage to the pulp. The fractured enamel and dentin are cleaned using a moist cotton pellet and then dried with air blown indirectly over the fracture. Cover the exposed dentin with eugenol-free calcium hydroxide, such as Dycal. Acid-etch the enamel and rinse with water for 20 seconds before restoring the tooth with composite. Do so without using rotary instruments for additional preparation in order to prevent further injury to the pulp. Build up the composite in such a way that further rotary smoothing is not necessary and make sure the tooth is slightly out of occlusion.
The injured tooth can be permanently restored 6 to 8 weeks later after clinical, vitality, and radiographic examination shows no evidence of pulpal or periapical changes. It should then be monitored at 3, 6, and 12 months post-injury, then annually for several years to watch for pulpal changes.
Fractures that extend into the pulp will cause sensitivity or pain to chewing or temperature changes. Pulp exposure is usually visible. Treatment is determined depending on whether the root is completely or incompletely developed, the size of the exposure, time since exposure, and final restoration needs.
For teeth with complete root formation that have a pinpoint exposure that has been present for less than a few hours, a pulp cap with calcium hydroxide can be considered. This will allow new dentin to bridge over the exposure site, preserving the uninflamed, vital pulp.
Clean the fractured enamel and dentin using a moist cotton pellet, dry with air blown
indirectly over the fracture, and cover the exposed dentin with eugenol-free calcium hydroxide, such
as Dycal. Acid-etch the enamel and rinse with water for 20 seconds before restoring the tooth with
composite. Avoid additional preparation using rotary
instruments in order to prevent further injury to the pulp. Build up with composite material and make sure the tooth is slightly out of occlusion.
Final restoration of a tooth with pulp capping should be delayed for 6 to 8 weeks. With healing, a dentin bridge may be seen on radiographs. Clinical, vitality, and radiographic examination should be performed prior to final restoration to check for signs of pulpal necrosis, canal hypercalcification, and internal resorption. A root-canal would be indicated if any of these were present.
Continue to monitor a pulp-capped tooth after the final restoration. Clinical, vitality, and radiographic examination should be performed at 3, 6, and 12 months post-injury, then annually for several years.
If a completely formed tooth has a pinpoint exposure and has also been displaced, pulp capping is a poor choice since the pulp likely has been already damaged from the apical end. Root-canal therapy should be considered from the start and the tooth treated with the protocol for displaced teeth. Also, teeth with inflammatory or degenerative changes from previous injuries, as indicated by reparative dentin narrowing the pulp cavity, should have root-canal therapy.
If a tooth with complete root formation has an exposure greater than pinpoint or has indication of previous trauma, standard root-canal therapy should be performed instead of pulp capping. Many times restorative considerations will also make this necessary to allow for a crown retained by a post and core.
The pulp can be extirpated, the canal shaped, enlarged, and filled with gutta percha in one appointment. Since these injuries are often emergencies worked into a full schedule, a pulpectomy can be performed on an emergency basis with final cleaning and filling accomplished at a subsequent appointment. Permanent restoration of the injured tooth can also be done at this time.
Teeth with incomplete root formation are treated somewhat differently. Pulp capping with calcium hydroxide, as described above, and the placement of a temporary restoration are recommended for pinpoint exposures that occurred within a few hours of the time of treatment. This provides a seal that allows for a reparative bridge of dentin.
A partial pulpotomy is recommended for pinpoint exposures present over a few hours and for larger exposures that occurred less than 24 hours before treatment. To be successful, the calcium hydroxide dressing must be placed in contact with healthy pulp that is not inflamed. This allows for continued apposition of the dentin in the coronal region of the tooth apical to the pulpotomy site.
Under local anesthesia, a water-cooled high-speed handpiece with a diamond bur is used to remove the pulp and adjacent dentin to a depth of approximately 2 mm below the level of the exposure. This should be done intermittently for brief periods and should be supplemented with copious irrigation with saline or water to avoid heating up the pulp and dentin.
Ultimately, the amount of pulp tissue removed is determined by the health of the pulp. If the remaining pulp is inflamed, as indicated by continued bleeding of the stump of the pulp for over 5 minutes, additional pulp tissue should be removed. All inflamed superficial pulp must be removed so the calcium hydroxide is in direct contact with healthy pulp. After removal of 2 mm of pulp tissue, allow several minutes for hemostasis to occur. Stop bleeding that occurs for more than 5 minutes by placing saline-moistened cotton pellets that have been squeezed almost dry over the bleeding pulp tissue and then holding pressure for 3 to 5 minutes. Should bleeding continue after this, additional pulpal tissue should be removed.
Once bleeding has stopped, a hard-setting, eugenol-free calcium hydroxide, such as Dycal, is placed over the stump of the pulp and the remaining exposed dentin. Temporarily restore the tooth with acid-etched composite resin as described above.
A traditional pulpotomy removing the pulp down to the level of the cervical line is necessary for a pulpal exposure that has been present for over 24 hours. It is performed in the manner just described, making sure to keep the diamond bur cooled well with water. The powdered form of calcium hydroxide may be easier to apply to the stump of the pulp given the increased depth present. It can be placed in the access cavity with an amalgam carrier and a rounded instrument used to gently place it in contact with the pulpal tissue, taking care not to pack it into the pulp. Dycal or other hard-setting, eugenol-free calcium hydroxide is then placed over the powdered calcium hydroxide and the tooth temporarily restored.
Injured teeth with incomplete root formation that have been treated with pulp capping or pulpotomy should not be permanently restored for at least 6 to 8 weeks. They should then be monitored for pulpal necrosis, internal resorption, or hypercalcification of the canal with clinical, vitality, and radiographic examination at 3, 6, and 12 post-injury and then annually thereafter.
Root fractures can be either isolated to the root or can include a fracture of the crown that extends into the root. Isolated-root fractures are relatively rare, while crown-root fractures are common.
Isolated-root fractures typically involve maxillary central incisors with complete root formation and are caused by a horizontal impact to the crown from the front. This impact moves the tooth palatal, resulting in a fracture at some level of the root. The alveolar process may also be fractured in these injuries, especially if the fracture is in the mandibular incisor region. Fights and impacts by foreign bodies (baseball bats, tools, etc.) are the usual cause of this type of root fracture.
Root fractures in the apical and middle thirds of the root are usually oblique with the apical edge of the fracture being on the labial. Fractures in the coronal third are also oblique, with the apical edge being on the palatal. If a root fracture is displaced, the coronal fragment is lingual and may be extruded.
A frontal impact from falls, motor-vehicle accidents, bicycle accidents, and impacts from foreign bodies are the usual cause of crown-root fractures. Beginning supragingivally on the labial surface, the fracture line extends in an oblique course below the gingival crest to the palatal side, usually exposing the pulp.
Tenderness on biting pressure is the main complaint of a patient with an isolated-root fracture. Clinically, the crown may be displaced lingually and may be slightly extruded, although the more apical the fracture the less displacement there will be of the crown. Bleeding of the gingival sulcus may be present. After a root fracture, the injured tooth may not immediately respond to electric-pulp testing or to cold.
Moving the crown gently in an anterior-posterior direction to look for mobility will often allow the examiner to discover the location of the fracture and to differentiate between a root fracture, crown-root fracture, and displaced tooth. The closer the fracture is to the crown, the more mobile the coronal fragment will be.
A periapical radiograph should be taken to evaluate any tooth that sustained significant trauma and can be important in the diagnosis of a root fracture. It can be difficult to see a fracture on a radiograph, however.
To be visible on radiographs, the central x-ray beam cannot deviate vertically from the plane of the fracture by more than about 15 to 20 degrees. If it does, the fracture will show up as an elliptical double fracture instead of a single oblique fracture.
If immediate displacement of the apical and coronal fragments has not occurred the fracture may not be visible. If chewing forces, edema, or granulation material cause separation of the fragments, subsequent radiographs may show the fracture.
When a fracture does not show on radiographs despite a strong clinical suspicion that one exists, additional periapical radiographs should be taken at different angulations from the initial exposure. Increase the vertical angulation of one radiograph by 15 degrees more than the initial radiograph and decrease the other by 15 degrees from the initial radiograph.
Tenderness on biting is also the main complaint of a patient with a crown-root fracture. A supragingival fracture line is frequently present on the labial surface to clinical examination. The coronal fragment may be slightly extruded and moving it anterior-posterior may be painful. Usually, it is not tender to apical palpation. Gingival bleeding may be present from the sulcus.
Since the oblique fracture line is perpendicular to the central x-ray beam and the lingual aspect is often not displaced, a crown-root fracture can be difficult to diagnose on a radiograph.
When an isolated-root fracture occurs apical to the gingival attachment and there is no separation or mobility of the coronal fragment, the tooth is taken out of occlusion by adjusting the opposing teeth. No splinting is necessary; however, the patient is cautioned to avoid biting down on this tooth.
If there is separation between the apical and coronal fragments, regardless if it is
in the apical, middle, or coronal third of the root, the coronal fragment is aligned to its proper
position by digital manipulation under local anesthesia. This is usually accomplished easily. If resistance is encountered, it is usually caused by interference from displaced bone fragments. These bone fragments should be repositioned before attempting further realignment of the coronal fragment.
Once the coronal fragment is clinically aligned with the apical fragment a periapical radiograph should be taken to confirm proper position. The tooth is then immobilized using a firm, acid-etched resin splint or a similar passive splint that can be applied without displacing the coronal fragment.
Under local anesthesia, the coronal fragment is separated from the periodontal attachments and removed. The depth of the fracture can now be better evaluated. Extraction of the remaining root is indicated when the fracture extends below one-third of the clinical root.
If the fracture does not extend below one-third of the clinical root, consider restoration of the tooth. Smoothen rough supragingival and subgingival edges and treat dentin or pulpal exposures as you would a crown fracture. If there is a pulpal exposure, and a root-canal is necessary, it can be completed at this time, or a pulpectomy can be performed with gutta percha filling at a later time.
Finally, a temporary restoration that has supragingival margins is placed. The fractured coronal segment can be used as a temporary restoration by bonding it with acid-etched resin to adjacent teeth.
The injured tooth should be splinted for 3 months. The splint is then removed and the tooth evaluated. If the coronal fragment is still mobile and there is no indication of pulpal necrosis, the splint can be replaced for an additional 1 to 2 months, making sure the tooth is taken out of occlusion by selective adjustment to the opposing tooth. After the additional splinting time, if the coronal fragment is still mobile and there is still no evidence of pulpal necrosis, it may be permanently splinted to the adjacent teeth.
Monitoring of the fractured tooth should be done at 3
weeks, 6 weeks, 3 months, 6 months, and 12 months from the time of the injury. Clinical exam should
evaluate the color of the crown, palpation of the facial aspect of the alveolus overlying the root,
vitality testing with electric-pulp testing and cold testing. Mobility testing, percussion, and periodontal probing should be checked when the splint is removed to evaluate for pulpal necrosis or a periodontal fistula.
Pulpal necrosis may occur only in the coronal fragment or in both the coronal and apical fragments. Should it occur, treatment options include extraction or endodontic therapy. The determining factor is the extent and prognosis of the endodontic therapy and the patient's desire. When only the pulp of the coronal fragment is necrotic, only this portion needs to be cleaned, shaped, and filled. The apical fragment does not require endodontic treatment. When both the coronal and apical segments have pulpal necrosis, both should be treated. If it is not possible to gain access to the apical fragment, a root-canal is performed on the coronal fragment and then the apical fragment is surgically removed.
Definitive treatment of crown-root fractures involves gaining subgingival access to the fracture for proper preparation of the margin of the final restoration. Several options are available depending on the depth and position of the fracture including gingival and/or osseous recontouring surgery, orthodontic extrusion of the root, or a combination of the two. Orthodontic extrusion is preferable if recontouring surgery would require removal of bone or gingival tissue on the labial, or if the fracture is greater than 2 mm below the level of the bone.
When the pulp is vital at the time of the injury, the tooth should be monitored clinically and radiographically for pulpal necrosis at 3, 6, and 12 months post-injury and annually for several years.
The most common tooth injury after crown or root fractures is displacement of teeth from their alveolar socket. Teeth may be displaced in laterally (posterior, anterior, medial, or lateral), apically (intruded), partially avulsed (extruded), or completely avulsed. Maxillary anterior teeth, especially central incisors, are the most common teeth displaced, followed by mandibular incisors.
The blood and nerve supply to a tooth enters via the neurovascular bundle that enters through the apex. When a tooth is displaced from its alveolar socket the neurovascular bundle is damaged to some degree. If the apex is displaced more than 5 mm, there is definite damage and immediate root-canal therapy will be necessary. If it is displaced less than 5 mm, damage may occur or the neurovascular bundle may be stretched without damage. Such teeth need to be monitored clinically and radiographically for pulpal necrosis, with root-canal therapy indicated only if necrosis occurs.
Teeth with roots that have an open apex and are not completely formed have a chance of revascularization without the need for endodontic therapy. The embryonic-dental papilla contains a capillary network that is receptive to revascularization instead of several distinct vessels found in teeth that have completed their development. If revascularization is not adequate, the pulp may become fibrotic or calcified.
Attaching the tooth to the alveolus, the periodontal ligament is also damaged when a tooth is displaced. In some cases, there is tearing of the periodontal-ligament fibers on only one side of the tooth, although usually all of the ligaments are torn. Damage to the periodontal ligament can lead to external resorption of the root surface.
After an injury, both the periodontal ligament and cementum are sensitive to damage from desiccation when out of the mouth, temperature change, contamination and manipulation. With minor damage to the periodontal ligament or when a tooth is rapidly replanted after an injury, the periodontal ligament may successfully reattach to the cementum, and with small cemental tears reversible resorption of the root surface may occur.
Unless the tooth is rapidly replanted into the socket, the periodontal ligament and cementum are irreversibly damaged and will not reattach normally. Instead, ankylosis occurs with the bone fusing directly to the root surface. Areas of bare cementum will lead to ankylosis.
When irreversible root or periodontal ligament damage occurs, there is progressive replacement of the root by bone, called replacement resorption. Occurring over months to years, replacement resorption is gradual and asymptomatic and no inflammation is present. Radiographically, the normal radiolucent space of the periodontal ligament is not present.
Replacement resorption is usually progressive; however, sometimes it may be transient. That is, some teeth that are totally ankylosed and immobile may become mobile to some degree later as small islands of ankylosis break away due to function over time. Normal attachment over the rest of the surface of the root maintains the tooth in the socket.
External-inflammatory resorption is much more rapid than replacement resorption. Sometimes there is significant resorption of a tooth in a matter of weeks. Thought to be due to the products of pulpal infection, inflammation is extensive and the resorption can be seen on a radiograph as a radiolucent area.
Timely root-canal therapy to remove the infected pulp can prevent or help stop external- inflammatory resorption. With displaced teeth, extirpation of the pulp and debridement should be performed once the tooth is stable, generally within 2 to 4 weeks. Calcium hydroxide should be used to temporarily fill the canal. It can be replaced every 3 months if external-inflammatory resorption continues. Final filling of the canal with gutta percha should be delayed for up to 12 months, as the lateral condensation puts considerable pressure on the healing periodontal ligament tissues.
Significant ankylosis can occur when an injured tooth has been out of the mouth long enough for periodontal ligament damage to occur. In children, such teeth do not erupt, leaving a tooth out of occlusion that cannot be moved with orthodontic therapy. In adults, ankylosed teeth remain in position and function well, although they may be difficult to remove should extraction become necessary.
Trauma to the teeth may fracture a tooth, displace a tooth, or separate or crush the supporting bone, periodontal ligament, or gingiva.
When teeth are separated from their periodontal ligament attachment, such as during an extrusion injury, there is a tearing of collagen fibers and intercellular material with limited damage to adjacent cells. Wound healing can occur rapidly since cells are not damaged.
Intrusion injuries, however, cause crushing of the supporting tissues with extensive damage to adjacent cells and intercellular material. Before the injured tissues can heal, these damaged tissues must be removed by macrophages and osteoclasts, which delays healing by several weeks.
Immediately after an injury, there is bleeding from damaged blood vessels with subsequent clotting and hematoma formation. Neutrophils migrate to the area to attack microorganisms that can cause infection. Macrophages digest damaged cells and foreign bodies. The injured area is then revascularized giving blood supply to ischemic tissue and forming new tissue in areas with tissue loss. Endothelial cells and fibroblasts then move into the injured area.
When a simple luxation-type of injury occurs to a tooth, new collagen fibers form within a week to repair the severed periodontal-ligament fibers. By the second week, the fibers have healed sufficiently to give the periodontal ligament about two-thirds of its normal mechanical strength.
When the vascular supply to the pulp is severed, new blood vessels begin to grow within 4 days following the injury and, in teeth with open apices (greater than 1 mm), they grow at a rate of 0.5 mm per day.
In injuries that severely damage the periodontal ligament, such as crushing injuries or desiccation following avulsion, root resorption may occur due to the loss of the layer of cementoblast and epithelial rests of Mallassez on the root surface. This loss allows macrophages and osteoclasts to remove damaged cementum and periodontal ligament from the surface of the root.
This can lead to complications of wound healing, including resorption of the root. Resorption depends on the eventual exposure of dentinal tubules, whether the pulp is sterile and ischemic or necrotic and infected, and presence or absence of vital cementoblast adjacent to the injury.
Resorption can be surface resorption, inflammatory resorption, or replacement resorption. In surface resorption, macrophages and osteoclasts resorb the surface of the root in response to damage of the innermost layer of the periodontal ligament, forming a shallow, curved depression on the root. If the adjacent cementoblast layer is intact and the damage does not extend into a dentinal tubule, the area of resorption is repaired by deposition of new cementum and Sharpey's fibers.
If the resorption has extended through the cementum exposing dentinal tubules, inflammatory resorption can occur. Bacterial toxins from infected pulp or dentinal tubules are transmitted via dentinal tubules to the area of resorption and the periodontal ligament. Inflammation in the periodontal ligament and continued osteoclastic activity causes resorption of the lamina dura and of the adjacent bone. This resorption, left untreated, will continue until the root-canal is exposed. If treated with root-canal therapy, the removal of the bacteria will stop the resorptive process and bone or cementum will fill in the cavity formed by resorption.
With extensive damage to the innermost layer of the periodontal ligament, replacement resorption may occur. With replacement resorption, healing from the periodontal ligament produces cementum and Sharpey's fibers at the same time that healing from the adjacent bone of the alveolar socket wall produces bone from bone-marrow cells. This can create a progressive ankylosis, making the tooth part of the bone remodeling process.
|Figure 3: Semi-rigid splint made from orthodontic wire and acid-etched bonding material.|
Splints are used to stabilize displaced teeth. The injured teeth are splinted to adjacent teeth. After one week of splinting, displaced teeth are reasonably stable and the splint is left in place for 10 to 14 days to allow for gingival reattachment. Prolonged splinting has been shown to promote ankylosis by preventing normal function of the tooth that fractures small areas of fusion of bone to cementum.
Semirigid splinting is assumed to assist healing of the periodontal ligament, but this has not been definitely proven. Rigid splinting does not seem to promote healing, and in cases of prolonged splinting in injuries with extensive damage it seems to promote ankylosis.
Semirigid resin splints, constructed of orthodontic wire and acid-etched bonding material, provide stability while at the same time allowing functional motion to prevent ankylosis. These are normally used for a single displaced tooth when treatment is in a dentist's office.
|Figure 4: An Erich-arch bar used as a rigid splint is wired to the displaced tooth and to several teeth on each side using 24-gauge wire.|
An Erich-arch bar may be used when bonding techniques are not available, such as in many hospital emergency rooms. A segment of arch bar is cut long enough to include the displaced tooth and at least two teeth on either side. It is then attached circumdentally to each tooth using 24-gauge stainless steel wire. It is a rigid splinting technique, not allowing for functional motion of the injured tooth. Erich-arch bars are also used with many displaced alveolar fractures and with fractures of the mandible or maxilla.
Other techniques that can be used if nothing better is available include an Essig splint or periodontal-packing material.
A common injury is a horizontal displacement of a tooth due to a blow to the crown. Most often this is an anterior tooth and the tooth is displaced posterior, displacing the crown of the tooth posterior and the root anterior through the labial alveolar plate.
Maxillary central and lateral incisors are often affected. Common causes include a fall, a blow to the teeth from being punched by a fist, and sports injuries. Mandibular incisors are displaced often due to bicycle accidents, such as hitting an object and being thrown over the handlebars.
In such an injury, the neurovascular bundle is severed, some fibers of the periodontal ligament are torn, and some on the palatal aspect of the tooth are compressed, and the alveolar bone may be fractured.
The injury is usually obvious to the patient, who will complain that the tooth has been "knocked back." The patient may complain that the teeth don't come together or that the displaced tooth occludes before the others. There will be pain when touching the displaced tooth and surrounding structures. Bleeding may occur, but this stops quickly and usually is not a problem by the time the patient is seen by the dentist.
Clinical exam will show the crown to be displaced, often lingually, with the tooth firmly locked into the displaced position. There is little or no mobility of the tooth. The apex of the tooth can be palpated on the labial. Vitality testing shows no response to cold or electric-pulp tests. A hollow or metallic sound is produced from percussion testing.
A radiograph should be taken to rule out root fractures. With a laterally displaced tooth, it will show widening of the periodontal-ligament space. It may show an increased space at the apex if the radiograph was taken at an oblique angle to the normal horizontal angulation of the tooth. If the tooth has been displaced mesial or distal, there may be a widened periodontal-ligament space on the opposite side.
Local anesthesia is used to anesthetize the region before repositioning the tooth. Then, steady digital pressure is applied to the tooth to reposition it into normal anatomical position. Pressure is applied to the lingual surface of the crown pushing it labial, while pushing the apex lingually with pressure on the labial mucosa over the displaced apex of the root. Once the apex is pushed back through the fenestration in the labial plate, pressure is placed in an apical direction to seat the tooth firmly in the socket.
If a tooth is displaced in a position other than posterior, use the same digital manipulation technique to reposition it into proper position. Evaluate the occlusion to make sure the tooth is properly aligned.
Bone fragments that can be palpated on the labial or lingual should be repositioned with digital pressure. Any lacerations to the gingival are sutured at this time.
An acid-etched semirigid splint should be placed to immobilize the tooth as described previously. A rigid splint, such as a wire splint or Essig splint may be used if bonding material is not available (for example, in a hospital setting.) Be sure to adjust the occlusion by selective grinding of the opposing tooth so that the splinted tooth is not in hyperocclusion.
A tooth displaced over 5 mm that cannot be completely repositioned may be moved with orthodontic repositioning after the bone has healed.
Three weeks after the injury, a periapical radiograph is taken. If it shows no loss of marginal-bone support for the tooth, the splint can be removed.
For a resin and wire splint, the splint is removed by using a high-speed fissure or diamond to remove the wire from the resin. Care must be taken to avoid excessively manipulating the repositioned tooth, so as not to cause its displacement. Support the incisal edge of the tooth while grinding the splint off. After the wire is removed from the tooth, smoothen the excess resin, but avoid additional manipulation for several weeks for further healing to occur before removing it at all.
If the 3-week radiograph shows loss of marginal bone, the splint should be left in place for another 5 to 8 weeks from the time of injury.
Check the radiograph for signs of external-inflammatory resorption. If resorption is occurring, root-canal treatment should be started immediately. Use calcium hydroxide to temporarily fill the canal for the first 6 to 12 months before permanently obturating the canal with gutta percha.
If there are no signs of external-inflammatory resorption in a tooth with a fully developed root and closed apex, and the tooth was displaced more than 5 mm, root-canal therapy should be performed as soon as possible. Again, use calcium hydroxide to temporarily fill the canal for the first 6 to 12 months before permanently obturating the canal with gutta percha.
A tooth with a fully developed root that was displaced less than 5 mm and that has no signs of external-inflammatory resorption should be clinically examined at 3, 6, and 12 months after the injury. Check for signs of pulpal necrosis or external-inflammatory resorption with radiographic and clinical testing, including evaluation of color of the crown, percussion, palpation, mobility, and electric- and cold-vitality testing. If there is a periapical radiolucency present or there are clinical signs of a non-vital tooth, standard root-canal therapy is performed with permanent gutta percha obturation. Temporary filling with calcium hydroxide is not needed.
If a tooth has an incompletely developed root with open apex, no endodontic therapy is performed unless there are signs of pulpal necrosis. Monitor the tooth monthly with radiographic and clinical examinations until there is evidence of continued root growth or pulpal necrosis. If pulpal necrosis occurs, endodontic therapy is started immediately using calcium hydroxide as a temporary filling material for 6 to 12 months before permanent obturation with gutta percha.
After 12 months, if the apex is still not closed adequately, continue temporarily filling with calcium hydroxide until apexification occurs, closing the apex so that a permanent filling can be performed.
A displaced tooth that cannot be completely repositioned may be moved with orthodontic repositioning. If it was displaced over 5 mm, start root-canal therapy with temporary calcium hydroxide filling before beginning orthodontic movement. If it was not displaced over 5 mm, orthodontic movement may be started as soon as the splint is removed. The tooth is still monitored for pulpal necrosis and external-inflammatory resorption during orthodontic movement. Should either occur, root-canal treatment may be initiated during orthodontic treatment.
A blow to the crown of a tooth from an angle oblique to the long axis of the tooth partially displaces (extrudes) it from its socket. The neurovascular supply is severed, as is most of the periodontal ligament. Some gingival fibers on the palatal may be intact.
The patient will complain that the tooth is "knocked loose," or that the teeth don't come together properly. The tooth may be extruded and may occlude before the other teeth.
Clinical exam will show the tooth to be elongated, loose, and often displaced lingually. The tooth is non-vital to testing with cold- and electric-pulp tests. Percussion is not necessary, although it would cause a dull sound. Radiographic exam will show an increased periodontal space in the apical region of the socket.
After administration of local anesthesia, slow, steady apical pressure should be applied to the crown of the tooth to reposition the tooth in the socket. The pressure will displace the clot that was formed in the apex of the socket.
Once the tooth is repositioned, an acid-etched semirigid splint should be placed to immobilize the tooth as described previously. A rigid splint, such as a wire splint or Essig splint may be used if bonding material is not available (for example, in a hospital setting.)
Adjust the occlusion by selective grinding of the opposing tooth so that the splinted tooth is not in hyperocclusion. The splint is left in place for 3 weeks.
If the tooth was displaced more than 5 mm at the time of the injury and has a complete root, then immediate root-canal therapy should be started using calcium hydroxide as a temporary filling material for 6 to 12 months before permanent filling. If the tooth was not extruded 5 mm, it can be monitored for signs of pulpal necrosis or external inflammatory resorption, as discussed in the lateral displacement section.
At three weeks after the injury, a periapical radiograph is taken to evaluate whether or not external-inflammatory resorption is taking place. If so, root-canal therapy is immediately started, using calcium hydroxide as a temporary filling for 6 to 12 months before permanent obturation with gutta percha.
An extruded tooth with an open apex and incomplete root formation should not have root-canal treatment unless there are signs of pulpal necrosis or external-inflammatory resorption. If either occurs, endodontic therapy is started immediately using calcium hydroxide as a temporary-filling material for 6 to 12 months before permanent obturation with gutta percha. After 12 months, if the apex is still not closed adequately, continue temporarily-filling with calcium hydroxide until apexification occurs, closing the apex so that a permanent filling can be performed.
A blow along the long axis of a tooth will force the tooth into the alveolar process, causing severe damage to the periodontal ligaments and neurovascular bundle. The alveolus is fractured or crushed. External-inflammatory root resorption and loss of marginal alveolar bone is common.
The patient will relate a history of trauma, causing impaction or "loss" of the tooth. An intruded tooth may be partially visible or may be completely intruded into the socket and not visible, causing the patient to think it was "knocked out."
The shortness of the crown in adult dentition is an indication that intrusion has occurred. The tooth is usually not mobile, not sensitive to percussion, and does not respond to vitality testing with cold- or electric-pulp testing. Percussion may produce a metallic sound.
If the tooth is not present on clinical examination, a periapical radiograph should be taken to determine if the tooth is avulsed or intruded. If it is intruded, it will radiographically be displaced and the periodontal-ligament space will be missing apically.
A maxillary-central incisor may also be completely intruded with its root protruding through the alveolar process and into the floor of the nose. This can be determined by examination of the nares.
In mixed dentition, it may be more difficult to determine if the tooth is intruded or is just erupting, as the tooth will not be mobile. The child or parent may be able to determine if the tooth is in the pre-injury position. Tooth height can be compared to the height of the adjacent non-injured tooth. Percussion may help in the determination. An erupting tooth should have a dull sound, while an intruded tooth may have a metallic sound.
An intruded tooth with incomplete-root formation will usually spontaneously reerupt and no treatment is required for this tooth. It should be monitored clinically and radiographically to make sure eruption is occurring.
The exception is if the tooth has perforated the floor of the nose. In such cases, the tooth should be repositioned with forceps and then stabilized with an acid-etched wire and resin splint, as described previously. The splint should be left in place for 2 weeks.
It is unpredictable whether a tooth with complete-root formation will spontaneously reerupt. Therefore, the best treatment is to extrude the tooth with orthodontic treatment over a period of 3 to 4 weeks. As soon as possible after any swelling has subsided, this treatment may be started. If the tooth is completely submerged, surgical exposure may be needed and a bonded bracket placed.
Again, if the tooth has perforated the floor of the nose, it should be repositioned with forceps and stabilized with a splint.
Intruded teeth are at high risk for pulpal necrosis and external-inflammatory resorption due to the severe injury to the neurovascular supply and to the periodontal ligament. They must, therefore, be monitored closely.
A tooth that was intruded enough that it required surgical repositioning should have the splint removed in 2 weeks and then have endodontic therapy started immediately. The tooth is opened, the pulp extirpated, and the canal cleaned. Calcium hydroxide is placed as a temporary filling for 6 to 12 months at which time a permanent gutta percha filling is placed.
If an intruded tooth with a complete root and closed apex is extruded with orthodontic therapy, it should be opened and the pulp extirpated at two weeks post-injury. Calcium hydroxide is placed as a temporary filling for 6 to 12 months at which time a permanent gutta percha filling is placed.
A tooth that had incomplete-root formation and was not treated when the injury occurred should be clinically evaluated 3, 4, and 6 weeks after the injury, and then radiographically at 3-, 6-, and 12- month intervals, watching for signs of spontaneous re-eruption, pulpal necrosis, or external-inflammatory resorption.
Should a radiograph show a periapical radiolucency or signs of external resorption of the root, endodontic therapy should be instituted immediately. The canal should be opened, debrided, and temporarily filled with calcium hydroxide. It should be reopened, cleaned, and repacked with calcium hydroxide at 3-month intervals for 6 to 12 months before permanent obturation with gutta percha. After 12 months, if the apex is still not closed adequately, continue temporarily filling with calcium hydroxide until apexification occurs, closing the apex so that a permanent filling can be performed.
Avulsion is the complete traumatic removal of a tooth from its socket, usually from a frontal horizontal (straight-on) impact, such as from a fall or being hit in the mouth. It occurs most often in younger patients who have elastic periodontal ligaments. Avulsion almost always occurs with maxillary-central incisors. Mandibular teeth and other maxillary teeth are rarely affected.
The neurovascular supply and periodontal ligament are torn from the tooth, creating a non-vital tooth. If the tooth is reimplanted soon after the injury, it may reattach and be a functional tooth. If it is not reimplanted within 2 hours, the body may treat it as a foreign body and rapid resorption may occur, causing loss of the tooth.
The long-term prognosis of an avulsed tooth depends on the length of time out of the socket and the contamination or damage to the root surface. Determine the mechanism of injury, when the accident occurred, how long the tooth has been out of the socket, and what has been done with it in the interim. How has it been stored? Has it been cleaned?
The length of time the tooth has been out of the mouth has a bearing on the prognosis. The longer it has been out, the greater the chance that the root will have external-inflammatory resorption. Teeth that are out of the mouth for 30 minutes or less have a 10% chance of external resorption. At 30 to 60 minutes, there is a 50% chance, and at 2 hours there is a 90% chance.
Examine the avulsed tooth and the remaining socket. Check the tooth for fractures, contamination, and presence of completely or incompletely formed apex. Evaluate the periodontal ligament. Is it intact on the root surface or has it been disturbed by trauma or a previous attempt to clean the tooth? Evaluate the root for fractures and a radiograph taken if a fracture is suspected.
Examine the socket to check for fractures of the alveolus, intact buccal and palatal bone, and evidence of advanced-periodontal disease. If a tooth is to be reimplanted, the alveolus should be reasonably intact and the socket free of periodontal disease.
General guidelines suggest that a tooth should not be reimplanted if it has been avulsed for over 2 hours since the long-term survival is low. Still, there may be times to consider reimplantation in these cases. Sometimes, parents may prefer or insist on trying reimplantation, even if the prognosis is not good. Even if the tooth is lost 2 to 4 years later, growth and development of the alveolus may allow for a better prosthetic result or implant site. A tooth that has been out of the socket for over 5 hours has almost no chance of success.
When possible, immediate treatment should begin before the patient is brought to the dental office, ideally within minutes of the accident. Teeth that are reimplanted by the patient or parent have a better chance of survival than those that are left out until the patient can arrive at the dentist's office.
When informed by telephone of the injury, the dentist should advise the patient to clean the tooth by holding it by the crown and washing the root with cold water taking care not to touch the root surface with anything except water. The root should not be scrubbed by any mechanical means. After the tooth has been cleansed it should be placed back into the socket, reimplanted with a back and forth rotation, then held in place with finger pressure or by biting on a cloth while the patient is immediately brought to the dental office.
If the tooth cannot be reimplanted or the patient or parents are unwilling to try, the tooth should be kept moist while being transported with the patient to the dentist. This is best accomplished by placing it in normal (physiologic) saline, salt water (1/2 tsp salt in 8 oz glass of water), or milk. If not available, the tooth can be kept moist in a wet towel, plastic wrap, or water, although this is not as satisfactory as milk or saliva. If nothing else is available, it can be held in saliva in the mouth in the buccal vestibule or under the tongue, although there is a risk of the patient swallowing the tooth with this method.
Once the patient reaches the dental office, the avulsed tooth should be placed in normal saline solution while the history is taken, and examination of the tooth and patient performed. The tooth should be rinsed with normal saline until any dirt or debris is removed. Be sure to include the open apex of an incompletely formed tooth. If needed, debris that cannot be washed off can be removed with an instrument, such as cotton pliers, or gently with the corner of a gauze sponge moistened in saline. Handle the tooth only by the crown.
Flush and suction the clot from the socket before reimplanting the tooth. Push apically with digital pressure to seat the tooth firmly in the socket. If resistance is met, remove the tooth and place it in saline while reevaluating the socket to make sure any debris or obstruction is removed. In cases where the buccal plate has been compressed, it may need to be gently expanded by placing a flat instrument, such as a straight elevator, into the socket and pressing in an anterior direction. This is not often necessary.
|Figure 5: Oral view of avulsed teeth # 8 and 9. If the avulsed teeth are not present with the patient, the differential diagnosis must include intrusion of the teeth.||Figure 6: Care must be taken with avulsed teeth to not damage the periodontal ligament during handling or cleaning and to keep them moist before reimplantation. Note fractures of the teeth in addition to avulsion.|
|Figure 7: Reimplanted teeth stabilized with Erich-arch bar. Wire over incisal edge is to maintain tooth in apical position.||Figure 8: Periapical radiograph of reimplanted teeth after endodontic therapy, with arch bar still in place.|
If a tooth had been reimplanted prior to being seen by the dentist, a radiograph can be taken to check for fractures and the adequacy of the reimplantation. If it appears that the tooth was rinsed and cleaned before reimplantation and it is properly seated, it may be splinted without removal. If not, remove it, placing it in saline, while debriding and rinsing the socket. Then reimplant the tooth into the socket.
Once the tooth is seated in the socket, check the occlusion to make sure the tooth is in proper position. Some dentists take a radiograph to verify the position in the socket; however, this is usually evident by clinical examination.
Immobilize the tooth by placing an acid-etched resin and wire splint or Essig splint, as described in previous chapters and suture any soft tissue lacerations. Relieve the occlusion so that the tooth is slightly out of contact during the healing phase.
Prophylactic-antibiotic therapy should be started. If not allergic, penicillin VK 500 mg, two immediately and then one every 6 hours for ten days, is generally used. If the wound or tooth was contaminated with soil, administration of tetanus toxoid is recommended and the patient should be referred to the patient's personal physician, or immediate-care center.
A pulpectomy should be performed within 2 weeks of the injury and before splint removal. The canal should be filled temporarily with calcium hydroxide. Every three months for the first year the canal should be recleaned and repacked with calcium hydroxide. Should the tooth become symptomatic in between packings, the patient should be seen at once and the canal recleaned and repacked. At one year, gutta percha can be used to permanently seal the canal.
If the avulsed tooth had an open apex at the time of the injury and after 1 year the apex still has inadequate closure, continue the process of temporarily filling with calcium hydroxide until apexification has occurred and adequate closure is present for a gutta percha filling.
The splint should be left in place for 10 to 14 days while the tooth is healing. For a resin and wire splint, the splint is removed by using a high-speed fissure or diamond to remove the wire from the resin. Care must be taken to avoid excessively manipulating the reimplanted tooth, as to not cause its displacement. Support the incisal edge of the tooth while grinding the splint off. After the wire is removed from the reimplanted tooth, smoothen the excess resin, but avoid additional manipulation by waiting for several weeks for further healing before removing it all. If an Essig wire splint was needed, remove it under local anesthesia.
An avulsed tooth with incomplete-root development that was reimplanted within 2 hours may reattach and develop a neurovascular supply, similar to a tooth that is transplanted. Pulpectomy can be delayed until there are signs of necrosis of the pulp. Monthly clinical examinations should be performed checking for color changes in the crown, swelling, sinus tract development, or other indications of pulpal necrosis. Mobility, sensitivity to palpation, and percussion should be evaluated. Periodically, radiographs should be taken to watch for root resorption or periapical radiolucency. The tooth should be watched monthly until there is evidence of continued root formation or pulpal necrosis. If there is continued root formation, clinical examinations can be made every 3 months for 1 year and then annually.
Should there be evidence of pulpal necrosis or resorption, a pulpectomy should immediately be performed and the canal filled with calcium hydroxide. Follow-up should be the same as with a tooth that had an immediate pulpectomy.
It is estimated that trauma to primary teeth occurs in up to 25 to 30% of young children. Many injuries are minor, going undetected by parents, although they may require future treatment.
Injuries to primary teeth occur primarily to the anterior teeth, especially the deciduous maxillary-central incisors. Younger children, aged 1 1/2 to 2 1/2 years old, have the highest incidence. This corresponds to the time the child is learning to walk and run. Frequently, the injury is caused by falling on the edge of a table, falling off a bed, or out of a stroller, or by tripping over toys, sidewalks, or steps. As children get older, the incidence of these types of injuries to primary teeth decreases. Motor-vehicle accidents cause serious injuries to primary teeth and the facial bones, especially if the child is not in a properly restrained car seat.
Injuries to the primary teeth may also be caused by child abuse. In the United States, estimates are that hundreds of thousands of children are abused every year. Child abuse should be suspected if there are injuries to primary teeth along with other facial injuries to the oral cavity, face, and head. Often, abuse is repetitive and the incidence of injury occurs over time. Dentists are morally and legally obligated to report suspected cases of child abuse to authorities.
Treatment decisions regarding injured primary teeth are based on several factors. The extent of the injury is a main factor. Often, children sustain injuries to multiple-primary teeth at the same time. Avulsion, root fractures, crown fractures, and displacement may all be present in the same patient. Behavior and cooperation of the child is another factor in treatment decisions. At best, very few children under the age of 2 years are able to be good dental patients. After an injury, these young patients are scared, in pain, and are not cooperative or normal. The ability of the child to cooperate with examination and treatment affects the treatment plan. The parent's wishes and concerns about the treatment affect treatment decisions too, as well as their willingness, ability, and cooperation to help manage behavior.
Given the complexity of the injury, patient behavior, and parental wishes, ideal treatment may not be possible for difficult problems and compromises may be necessary.
In evaluating an injured child, a good history of the accident is important. When the accident occurred; the mechanism of injury (fall, motor-vehicle accident, etc.); whether teeth are broken, displaced, or avulsed; the presence of lacerations or bleeding from the mouth or face; and whether there was a loss of consciousness or a head injury these are some of the facts that need to be determined. It can be difficult to ascertain the exact mechanism of injury from the child if the accident was not witnessed by an adult. Medical history, including medications taken, should be reviewed.
In many falls, the child strikes not only the mouth, but also the skull. Should there be any indication of concomitant trauma to the head, especially if there was a loss of consciousness at the time of the injury, the child should be seen by a physician or emergency–hospital personnel to rule out head injury.
The clinical exam is sometimes difficult due to the lack of cooperation from the child. Starting with an extraoral exam, the patient is checked for lacerations and abrasions; facial bones and mandible are palpated to rule out fractures. Palpation of the mandibular condyles is important, as condylar fractures occur most often when the chin or anterior mandible sustains a blow from the front, the same mechanism that causes injury to primary teeth. The occlusion and alignment of the arches should be examined. Teeth should be evaluated for injuries, including fractures, pulpal exposure, displacement, or avulsion. Examination should be gentle, especially with regards to percussion and mobility testing, as pain from the examination can upset the child and make him or her uncooperative. Electric-pulp testing is not useful as it is unreliable in young children and in recently injured teeth. Lip, tongue, and gingival lacerations are common with pediatric injuries to the mouth, so a good soft tissue examination of the oral cavity is important.
Radiographic examination of the injured teeth is important, but can be difficult due to the lack of cooperation from the patient. The child may need to sit in the parent's lap with the parent holding the film holder for the patient. Adult-sized periapical film can be placed in a film holder and positioned as if a maxillary or mandibular occlusal film was being taken.
Injured-primary teeth should be monitored over the long term for pulpal necrosis and resulting abscess. Tooth color can be an indication of the status of the pulp. Some injured teeth will immediately change color due to hemorrhage inside the pulp chamber. This will fade over time if the pulp maintains its vitality. If discoloration occurs late, it may be due to pulpal necrosis or pulp chamber calcification.
Decomposition of the pulp in pulpal necrosis can turn a tooth various shades of gray, sometimes almost black. Often the color change will occur before there are clinical symptoms or radiographic changes. Pulpectomy is indicated, although extraction is an alternative.
Primary teeth may turn yellow following a traumatic injury. This is a reparative response in which secondary dentin develops in response to the injury and obliterates the pulp chamber. The increased dentin shows through the relatively thin enamel of primary teeth to give them a yellow color. Even though this is a pathologic response, no treatment is necessary and these teeth will resorb naturally.
As with a permanent tooth, a traumatic blow to a primary tooth may cause a concussion or subluxation without fracturing or displacing the tooth or alveolus. Hemorrhage and edema within the periodontal-ligament space and edema in the pulp may occur. The periodontal ligament remains intact with a concussion and, therefore, there is no mobility of the tooth. With subluxation, the periodontal ligament is torn and the tooth loosened.
A concussion type of injury is common in children and the parents are frequently not aware of the injury unless the child complains.
Clinical examination shows considerable sensitivity to both vertical and horizontal percussion. Initially, both electric- and cold- vitality testing may show no response. No radiographic findings are present with either concussion or subluxation. With concussion, the tooth is attached normally to its alveolar socket and not mobile. Bleeding from the gingival sulcus is generally not present. With subluxation, the tooth is loosened in its socket, although it is not displaced, and some bleeding may be present in the gingival sulcus.
No immediate treatment is needed for a concussive injury. The tooth should be monitored on a long-term basis to watch for the possibility of pulpal necrosis, although this is not common.
Immediate treatment of subluxation injuries to primary teeth depends on the mobility of the tooth. Usually, it is not very mobile and no treatment is necessary. If the tooth is somewhat mobile, but not excessively so, and the patient is cooperative, an acid-etched splint can be placed. The tooth should be extracted if it is so mobile that it might fall out or there is concern that it could be swallowed or aspirated. Primary teeth sustaining subluxation injuries usually tighten up on their own. They need to be periodically evaluated with clinical and radiographic examinations to watch for pulpal necrosis.
Primary teeth are frequently fractured due to falls and other childhood injuries. Often, multiple teeth will be injured.
A fracture of the enamel of a primary tooth requires no treatment other than smoothing out any rough surfaces with a diamond bur. It should then be monitored for the remote possibility of pulpal necrosis.
When only small amounts of dentin are exposed in a fractured tooth, all that is necessary is to smooth out any rough edges with a diamond bur. When larger amounts of dentin are exposed, an indirect pulp cap is indicated. Place calcium hydroxide, such as Dycal, over the exposed dentin. Cover this with an acid-etched composite restoration. The tooth should be monitored for future pulpal changes.
When a fractured primary tooth has a pulp exposure that has been present for less than 2 hours, a formocresol pulpotomy is indicated, followed by a composite restoration or crown. A pulpectomy, filling the canal with a zinc oxide and eugenol paste, is indicated if the pulp exposure is present over 2 hours.
Isolated-root fractures are not common in primary teeth, but they do occur at any location on the root. Fractures in the apical one-third of the root do not need treatment if the tooth is stable and not mobile. Extraction is necessary for teeth with fractures occurring in the middle or coronal thirds of the root if they are moderately or severely mobile. Care should be taken in removing the apical fragment in order to prevent damaging the underlying follicle of the permanent tooth. It is better to leave a fragment of root in the socket than to damage the follicle. Resorption by the erupting permanent tooth will occur. If a root fragment is left in place, it should be periodically monitored and the parents informed of the decision.
Crown-root fractures extending to the cervical region of the crown are generally non-restorable and extraction is the treatment of choice.
Injuries to Primary Teeth
Primary teeth will be displaced to the palatal if they receive an impact to their labial surface and will be displaced to the labial if they receive an impact from the palatal side, such as if the child were to hit the edge of a table with the mouth open. Displacement to the mesial or distal is also possible in severe injuries. In all cases, the teeth will be displaced and mobile.
No treatment is necessary if the displacement is minor and the teeth are stable, as the teeth will usually tighten spontaneously. If there is significant displacement, either extraction or repositioning with splinting is indicated. If the child is cooperative, an acid-etched splint can be placed after manually repositioning the tooth into proper position and checking occlusion. The tooth should be monitored long term for pulpal necrosis. Extraction is best in cases of severe displacement, fracture of the alveolar bone, or extrusion.
An impact on the incisal edge of a primary tooth may force it apically into the pliable alveolar bone. The intrusion may be minor or the tooth may be pushed completely into the socket. It may be forced directly into the underlying follicle of the developing permanent tooth or may be forced labial, missing the follicle.
When an injured tooth is clinically missing, a radiograph can determine if it is intruded or avulsed. Since treatment is determined by whether the tooth is labial or into the underlying follicle of the developing tooth, an occlusal film can be used to take a lateral radiograph of the area to determine its position.
If the tooth is labial to the developing tooth, it can be left alone to reerupt. Most often it erupts into normal alignment if it is the first time it has been intruded. This generally occurs within 3 months and the tooth may remain vital or may develop pulpal necrosis. If it has not moved in 3 months, it should be extracted since ankylosis can occur impeding eruption of the permanent tooth. Should subsequent intrusion injuries occur, the tooth does not generally reerupt and extraction should be the treatment of choice.
A tooth that is intruded straight into the follicle of the underlying permanent tooth should be extracted to prevent damage to the developing tooth.
Managing Dental Injuries
Primary teeth that are extruded will be elongated, mobile, often rotated, and there will be bleeding around the gingival.
When extrusion is minimal, the tooth is stabile, and there is no interference with the opposing occlusion, no treatment is necessary, as it will tighten on its own. Repositioning or extraction can be performed on very mobile primary teeth that are extruded over a distance of one-third the length of the crown.
With a cooperative child, repositioning is accomplished under local anesthesia by manipulating the tooth into proper position and splinting it to adjacent teeth with an acid-etched resin splint.
Although avulsed primary teeth have been reimplanted, the prognosis is poor and the recommended treatment is to not reimplant them. The wound will quickly heal like an extraction site. Maintenance of space is not a problem in the anterior arch and space maintainers are not advised. However, a fixed or removable prosthesis may be placed for esthetic reasons if parents wish replacement of the tooth.
Soft-tissue lacerations of the oral cavity and lips are common with pediatric injuries. Most are superficial and minor, requiring examination and debridement without suturing. Tongue and lip lacerations may require suturing depending on the depth and extent. Stripping of the labial gingiva and mucosa on the maxillary or mandibular alveolus is a common injury with falls. The wound should be debrided and irrigated before reapproximating the tissue and suturing it in place.
Temporomandibular-joint (TMJ) disorders are a common problem which dentists see on a regular basis. The term "TMJ" is a general term to describe all of the specific disorders that may occur. Some start as acute injuries, while others are caused by long-term mild problems that progressively get worse causing chronic disease.
Acute disorders of the temporomandibular-joint can be classified as those arising in the joint itself or in the surrounding musculature. Acute-joint disorders include traumatic posterior capsulitis, anterior dislocation of the disc without reduction (closed lock), sprained-capsular ligament, and dislocation of the mandible (open lock).
Fractures of the mandibular condyle can also injure the temporomandibular-joint. These injuries will be discussed in the chapter on fractures of the mandible.
The temporomandibular-joint is a synovial joint between the mandible and temporal bone of the skull. The condyle of the mandible articulates with the glenoid fossa and articular eminence or the temporal bone. An articular disc separates the glenoid fossa and condyle, forming an upper and lower compartment. The condyle moves on the inferior surface of the articular disc within the lower compartment, while the superior surface of the articular disc articulates with the glenoid fossa and articular eminence. As a synovial joint, synovial cells that line the tissue to the joint compartments produce synovial fluid that lubricates the joint during function.
A deep depression
on the inferior surface of the zygomatic process of the temporal bone, the glenoid fossa (also known
as the articular fossa or mandibular fossa), is where the condyle of the mandible, an oval-shaped
head on the condylar neck of the mandible, articulates during opening and closing hinge movements.
On opening the mouth wide,
Managing Dental Injuries
the condyle moves (translates) anterior and inferior along the articular eminence (also known as the mandibular eminence, or articular tubercle) a bony prominence anterior to the glenoid fossa. During protrusive movements, both condyles move forward together along their respective articular eminence. During lateral-excursive movements, the condyle on the ipsilateral side of the movement stays in the glenoid fossa, while the contralateral condyle translates out of the fossa and along the eminence.
The articular disc is a biconcave, oval-shaped pad composed of flexible fibrocartilage that lies between the mandibular condyle and glenoid fossa. It is always considerably thinner in the central region than in the periphery. It acts as a shock absorber and travels with the mandibular condyle when it translates forward out of the glenoid fossa. The tissue that continues posterior to the disc, called the retrodiscal pad, is a thick layer of loose and vascularized connective tissue that is highly innervated. This loose tissue allows for the anterior movement of the condyle during protrusion and opening. It is stretched tight at full protrusion. The vascularity of the retrodiscal pad allows for edema and swelling if injured. Anteriorly, the articular disc and capsular ligament are fused and contain fibers of the lateral pterygoid muscle. The lateral pterygoid muscle inserts into the anterior aspect of the neck of the mandibular condyle and also to the articular disc, pulling the disc and condyle anterior during contraction.
The joint and articular cartilage are held in place by the capsular ligament, the major ligament of the temporomandibular-joint. This sleeve-like capsule is attached superiorly along the entire rim of the articular eminence and glenoid fossa, inferiorly to the circumference of the neck of the mandible, and attaches to the edges of the articular disc, holding it in place during movement of the mandible. It is reinforced laterally by the temporomandibular ligament, a thickening of the capsule, whose fibers run inferoposteriorly from the tubercle of the zygomatic arch to the lateral and posterior portion of the condylar neck of the mandible. This ligament helps prevent posterior movement or displacement of the condyle, such as from a blow to the front of the mandible, protecting the tissues behind the disc. Laterally and medially, the articular disc is attached independently to the lateral and medial poles of the mandibular condyle.
Auxiliary ligaments, including the stylomandibular and sphenomandibular ligaments, restrict anterior motion of the mandible to prevent it from being dislocated anterior to the articular eminence.
Posterior capsulitis, also known as traumatic capsulitis or intracapsular edema, is an inflammation of the retrodiscal tissue following an injury to the mandible. The tissues are highly vascular and innervated. An injury caused by the mandibular condyle being forced posterior into this tissue causes inflammation and edema which is painful and displaces the mandibular condyle. Non-traumatic causes of posterior capsulitis include edema due to arthritic exudates and infection.
A patient presenting with posterior capsulitis will report pain and difficulty opening the mouth occurring shortly after an injury to the face or mandible. It is also possible to cause posterior capsulitis by biting down on a hard object. Some patients report waking-up in the morning with posterior capsulitis. Often this follows a stressful day, presumably resulting in clenching or bruxing at night as the cause of the retrodiscal edema.
Symptoms include a dull, achy, constant pain directly anterior to the ear, which gets worse with function of the mandible. Although it may not be visible upon examination, a posterior open bite on the side of the injury is commonly noticed by patients. This is known as acute malocclusion and is due to the condyle being forced anterior by the swollen retrodiscal tissue, creating disocclusion.
Clinical findings of posterior capsulitis include tenderness to palpation over the affected joint, increased pain on opening and closing the mouth, and oral opening limited often to less than 40 mm. Posterior disocclusion of the affected side may be present, but is often too minimal to be noticed on clinical examination. Biting with heavy force, the patient may be able to bring teeth into proper occlusion, although this may cause considerable pain and may cause more edema.
At rest, the mandibular midline may be deviated away from the injured side. The amount of deviation depends on the amount of edema in the retrodiscal tissue and the extent to which the lateral-pterygoid muscle becomes hypertonic from continual contracture to keep the mandibular condyle away from the retrodiscal tissue. On opening, the mandibular midline will deviate toward the injured side.
Temporomandibular-joint radiographs are not necessary to make the diagnosis of posterior capsulitis. If taken, however, depending on the amount of displacement of the mandibular condyle by the retrodiscal tissue, they may show anterior positioning of the condyle within the glenoid fossa.
Managing Dental Injuries
Diagnosis of posterior capsulitis is relatively easy. Often taking a good history from the patient will establish the diagnosis even before clinical examination. The differential diagnosis would include a fracture of the condyle, anterior dislocation or the disc without reduction, or otitis externa. A fracture of the condyle should be considered if significant trauma to the face or mandible occurred. It is usually more painful and the occlusal abnormalities are greater. Anterior dislocation without reduction of the disc causes significant limited opening, often to less than 20 mm and deviation to the affected side, but not posterior disocclusion. Otitis externa, outer ear infection, can have sudden onset of pain in the temporomandibular-joint area, which is exacerbated by gentle pressure on the auricle of the ear, but is not associated with trauma.
Treatment is symptomatic in nature and the extent of treatment depends on the severity of the symptoms.
For many patients, all that is needed is explaining the problem and reassuring them that it is a temporary condition. They should eat soft foods and avoid any further impact to the retrodiscal tissue until the symptoms resolve, which may take several days. As the edema subsides, the occlusion will return to normal.
If the symptoms are more severe, ice packs are used over the joint for the first 24 to 36 hours. Ice can be placed over the affected temporomandibular-joint for 5 minutes and removed for the next 15 minutes, then repeated. After 2 to 3 days, moist heat is used instead of ice.
Over-the-counter nonsteroidal antiinflammatory drugs are useful to treat the pain and decrease the inflammation.
|Figure 9: Manual reduction of an acute anterior dislocation without reduction is performed by placing the thumb on the second molar on the locked side and using steady force to distract the condyle downward and medial.|
The articular disc moves on with the head of the condyle on translation movements to allow full opening of the mouth. If the ligaments that hold the disc in position become stretched or loose, the disc can become dislodged from its position superior to the condylar head and become locked anterior to the condyle.
Spontaneous return to normal position upon opening the mouth is called anterior dislocation with reduction and is the common cause for clicking sounds in the temporomandibular-joint. It is common in about half of the population.
Anterior dislocation without reduction, also called closed lock or complete anterior dislocation of the disc, is when the disc does not spontaneously reduce into normal position upon attempts to open the mouth. The dislocated disc blocks the path of the condyle in translation and it is not possible to open the mouth fully. The disc displaces anteriorly and medially due to the pull of the lateral pterygoid muscle and it thickens or becomes folded.
Anterior dislocations without reduction happen acutely and patients are immediately aware of their inability to open their mouth wide. Sometimes, there is a long history of anterior dislocation with reduction prior to the lock, and sometimes there is a history of joint clicking or symptoms that were present initially, but resolved prior to the current incident. Locking may be intermittent or permanent.
Often, an anterior dislocation without reduction happens without any previous history of temporomandibular problems. Sometimes the cause is trauma to the mandible, particularly a blow from the front, which forces the condyle posterior and the disc anterior. Opening the mouth wide, as in yawning, singing, or yelling, or when biting down on a hard object, is frequently the cause. In other cases, the patient may go to bed fine, only to wake up and being unable to open the mouth. Parafunctional habits, such as bruxism, may be the cause in these instances. The patient will be able to tell the dentist exactly when and under what circumstances the injury occurred.
On clinical examination, limited oral opening is present. Generally, the maximum intrinsical distance is only 20 to 30 mm, and the mouth cannot be forced open any wider by the dentist. Pain at rest is usually not present unless there is also posterior capsulitis. On attempted opening or clenching, however, there may be pain over the preauricular area. On opening and protrusion, the midline will deviate to the affected side. Lateral-excursive movement is normal towards the affected side and limited toward the contralateral side (less than 6 mm) due to the medial position of the disc.
Temporomandibular-joint radiographs are not usually needed to make the diagnosis of anterior dislocation without reduction of the articular disc. If taken, however, they will show that the condyle, instead of being properly centered, is displaced posteriorly and superiorly within the glenoid fossa.
Differential diagnosis would include only those disorders with immediate onset. The other diagnosis that has acute onset of sudden limited opening of the mouth is myospasm of the elevator muscles. With a myospasm of the elevator muscles, lateral-excursive movements of the mandible are not limited as they are with an anteriorly dislocated disc without reduction.
Attempting to reduce (recapture) the dislocated disc is the immediate treatment for an anterior-dislocated disc. On occasion, patients can do this on their own by moving the mandible in side-to-side movements.
If this does not work, the patient should be asked to close the mouth so that the teeth almost touch. The patient should then move the mandible laterally as far as possible away from the affected side. When the mandible is in full lateral-excursive movement, the patient should then open the mouth as wide as possible. This motion will sometimes cause the disc to self-reduce into proper position.
A manual manipulation by the dentist may be required if the above does not work. The goal is to reduce the disc into normal position. This procedure tends to work on acute dislocations without reduction that have been present for a short time, generally less than one week. In such cases, the retrodiscal tissues are generally healthy and the disc is not permanently distorted. Chronic dislocations or dislocations present for longer periods of time have a much less chance of being successfully reduced. Adhesions to the disc or permanent distortion of the disc and stretching of the ligaments and retrodiscal tissue make this procedure less predictable when the disc is chronically dislocated.
The factors that determine whether a manipulation procedure of an acute-disc dislocation will be successful include muscle spasms and the position of the condyle. When the superior portion of the lateral-pterygoid muscle is in spasm, as it often is when it is in pain, it pulls the disc anterior and medial. It must be relaxed in order to allow manual reduction of the disc. Sustained contraction due to pain can be relieved with an injection of local anesthesia into the muscle or, sometimes, by administering skeletal-muscle-relaxant medications. Elevator muscles can be contracted in spasm and can cause the joint space to decrease due to pressure in the joint and disc. Since the disc space must be increased to reduce the displaced disc, this makes a manipulation procedure more difficult. Having the patient try to relax the elevator muscles and avoid forceful closing of the mouth will help improve the joint space.
Most of the time the above procedures will relax the muscles enough to allow reduction of the disc. In cases where the spasms of the muscles are so sustained that it is not possible to relax the muscles, intravenous-conscious sedation or outpatient-general anesthesia by an oral surgeon may be required.
Condylar position is the final factor in reduction of an anteriorly displaced disc. The retrodiscal tissue is what physically reduces the disc into proper position and this is active only in translation movements of the mandible. During the manipulation procedure, the mandibular condyle must move into maximum protrusion to allow posterior displacement of the disc into proper position.
Manual manipulation of an acute-anterior dislocation without reduction of the disc is performed by placing a thumb on the mandibular-second molar on the locked side and the fingers extraorally along the inferior border of the mandible. Stabilize the head with the other hand. Ask the patient to try to consciously relax the muscles, then distract the joint by bringing the condyle inferiorly and anteriorly using firm, steady force pushing down on the molar and up on the inferior border. After downward distraction, move the mandible in lateral-excursive movements away from the affected side. As the disc is often medial as well as anterior, this will aid in reduction into proper position. At this point, with the mandible in full protrusion, ask the patient to open fully. The patient may often feel a "pop" in the disc as it is reduced into proper position and then the patient will be able to open mouth wide.
Repeat the procedure a second or third time if reduction does not occur. If muscle spasms seem to be a factor, consider the use of muscle-relaxant medication or conscious sedation. In chronic dislocations, the adhesions or distortion of the disc or the laxity of the retrodiscal tissue may make the dislocation permanent.
Once the disc is reduced and the
patient can open mouth wide, have the patient close the mouth in an anterior position, such as in an
incisal end-to-end position. If the patient
closes into maximum-centric occlusion, the disc may again displace anteriorly. An anterior-repositioning type of appliance is needed to hold the mandible forward while the retrodiscal tissue is healing. It should be worn continuously for the first 3 to 4 days and then gradually reduced to nighttime use only. Patients should be placed on a soft diet, avoiding biting down hard or chewing gum. Nonsteroidal antiinflammatory drugs may be used for pain management during healing.If an anterior repositioning appliance cannot be made immediately due to time or location (for example, hospital-emergency room), allow the patient to gently close into centric occlusion. Occasionally, the disc will remain in normal position. If not, sometimes once it has been reduced once, patients can learn to reduce it themselves by manipulating their jaw position. Otherwise, schedule the patient soon for an appointment when the disc can again be reduced and an appliance made.
There is some controversy as to the best course of action when an anteriorly displaced disc cannot be reduced and is in a permanent lock. Procedures have been used to surgically reposition the disc and to tighten the retrodiscal tissues. These do reduce the disc, but shortening the retrodiscal tissue also tends to restrict translation movements and oral opening. If limited opening is associated with pain and does not resolve with conservative therapy over time, surgical repositioning of the disc can then be considered.
There is also a concern that the disc must be in proper position to avoid future problems with the joint, including degenerative arthritis. This is not true for most patients.
Based on cadaver studies, as much as half the population has some type of anterior dislocation of the disc (reducing or non-reducing) with no functionality problems. Education of the patient in regards to the mechanism of the condition, surgical- vs. non-surgical-treatment options, and home care are important. Treatment to reduce chronic forces on the retrodiscal tissue, such as appliances to reduce bruxism, may be the treatment of choice for many.
The patient should try to avoid opening the mouth wide at first. Instead, gentle opening and stretching to increase the range of motion should be advised. If the patient tries to open mouth too strenuously immediately after the injury, it only causes pain and rebound myospasm. Over the course of time, at least one year, the patient may regain a relatively normal range of motion.
The lateral aspect of the capsular ligament may be sprained, similar to a sprained ankle. Sprains may be caused by trauma to the jaw or by trauma from dental occlusion.
In the case of an acute injury, such as a blow to the jaw, the patient will have a specific history of pain following the injury.
Clinical examination will show pain to light palpation over the lateral aspect of the joint. There is no internal pain within the joint or while biting down hard. Radiographs of the temporomandibular-joint are not necessary.
These are minor injuries that resolve on their own within 2 weeks and treatment is not necessary. Symptomatic home care may be used, including ice packs, soft diet, and nonsteroidal antiinflammatory medication.
Injuries that cause the mouth to open wide, including opening wide during dental or surgical procedures, can cause the anterior dislocation of the mandibular condyle, also known as open lock or spontaneous dislocation.
As the condyle translates forward during translation and travels anterior to the articular eminence, the disc rotates to the posterior aspect of the condyle. If the condyle moves any further its anterior limit, the disc can be displaced anterior or posterior to the condyle. Forced through the disc space, the disc can become locked anteriorly. This can also occur if the lateral-pterygoid muscle contracts while the condyle is at its most anterior position of translation. The disc can also be displaced posteriorly behind the condyle. If any of these occur to the disc, the collapsed joint space does not allow the retrodiscal tissue to retract and pull the disc back into position. Elevator muscles contract to cause the condyle to remain in a locked, open-mouth position anterior to the eminence.
History is often enough to establish the diagnosis prior to clinical examination. The patient will relate difficulty with closing the mouth after some injury or incident in which the mouth opened wide. Yawning, singing, eating, dental treatment, and other activities that require opening the mouth wide are common causes. Frequently, the patient panics and rushes to the hospital-emergency room.
Clinical examination shows the patient to have the mouth open fully. The patient is not able to close the mouth and attempts to do so cause pain. The most-posterior teeth in the arch may be close to contact and the intrinsical opening will be wide, generally over 40 mm. Extraoral palpation of the condyles shows them to be prominent and anterior to the articular eminence.
The history of the immediate onset and inability to close the mouth in the absence of a significant injury to the chin establishes the diagnosis of anterior dislocation of the condyle. If there has been an injury to the chin, such as a fall or blow, bilateral fractures of the condyles need to be considered in the differential diagnosis. Such patients may present with a mouth wide open and inability to close due to pain and displacement of the bone. Patients with bilateral-condyle fractures are in significantly more pain than patients with dislocations.
Immediate treatment for dislocations of the mandible is reducing the dislocation by increasing the joint space to allow spontaneous return of the disc to normal position. Complicating this, however, is the strong, involuntary contraction of the elevator muscles attempting to close the mouth, which maintains the displacement of the disc.
Sometimes, patients can reduce the dislocation with help from the dentist. Have the patient open the mouth as wide as possible. Contraction of the depressor muscles of the mandible will occur, inhibiting the elevators. Simultaneously, the dentist should apply slight force to the chin in a posterior direction. Often, this will reduce the dislocation.
If it does not, the dentist may need to reduce the dislocation. Place thumbs on the alveolus immediately lateral to the last molars or on the posterior-mandibular teeth, while placing the rest of the hand over the inferior border of the mandible. Placing thumbs on the teeth will give better leverage; however, the thumbs should be wrapped in gauze because reduction causes sudden closure of the mouth due to spontaneous contraction of the elevator muscles. While asking the patient to try to relax the muscles, downward pressure is used to distract the joint space to allow spontaneous reduction of the disc.
This pressure should be enough to cause reduction, unless there is myospasm of the lateral-pterygoid or elevator muscles. If so, several options are available. Injections into the lateral-pterygoid muscles with local anesthesia without vasoconstrictor may help. If the elevator muscles are in spasm, they may also be injected. Conscious sedation usually will reduce the pain and relax the muscles enough to allow reduction. Outpatient-general anesthesia will always give enough relaxation to accomplish reduction.
After the reduction is accomplished, the patient should be placed on a few days of symptomatic-home care until any muscular or joint pain resolves. The patient should be advised of the cause and warned to be careful of opening wide during dental appointments and other times. Prevention is the best method to treat dislocations of the mandible and is certainly better than the surgical alternative.
Some patients develop chronic dislocations. In frequent or severe cases, a surgical procedure called an eminectomy can be performed. The steepness of the articular eminence is reduced through a preauricular approach, causing the disc to not move as far posterior when the condyle translates forward.
Lacerations of the oral or facial soft tissues frequently occur at the same time that teeth and dental structures are traumatized. Lacerations that range from minor abrasions to simple lacerations to complex wounds are commonly seen on the face, lips, tongue, oral mucosa, and gingival.
When possible, lacerations should be treated within a few hours of the injury. Treatment may range from simple debridement and cleansing of abrasions to the need to suture deeper wounds.
|Figure 10 : Facial laceration caused by hitting the steering wheel during a motor-vehicle accident. Such wounds should be checked for foreign bodies, communication to the oral cavity, and for fractures of the mandible.||
: Laceration sutured by closing the oral mucosa, then the muscle and subcuticular layers,
followed by the skin.
In general, soft-tissue wounds should be closed with meticulous attention to detail. The steps in closing soft-tissue wounds include cleansing, debridement, hemostasis, proper closure, and follow-up care.
Local anesthesia can be given as a regional block or local infiltration of the injured tissue. Sterile water is then used to mechanically cleanse the wound to remove all debris, foreign material, and clots. A sterile syringe can be used to irrigate the wound with some pressure. Evaluate the wound carefully and remove any fragments of fractured teeth. Any cyanotic fragments of tissue or tissue tags should be excised as this tissue will not survive, and may cause additional scar formation, and may become a focus for infection. Hemostasis must be assured. Continued bleeding into a wound after primary focus will form a clot that is subject to infection. Bleeding may be stopped with pressure, vasoconstrictors in local anesthesia, or, in more severe cases, by electrocautery. Larger blood vessels, especially arteries, which bleed persistently despite above attempts at hemostasis may need to be clamped and tied with 3-0 absorbable sutures.
After the wound is clean and bleeding is controlled, it is ready for primary closure. Note that any alveolar or other bone fractures or teeth repositioning should be performed before closure of the soft tissue. If the soft tissue is closed first, manipulation of the bones or teeth during reduction can disrupt the closed soft-tissue wound, causing more injury to the soft tissues.
The object of wound closure is accurate repositioning of the layers of tissue without open spaces on the surface or deep in the wound. In cases of superficial skin or mucosal lacerations, the surface layer is all that may need to be sutured. In deep wounds, a multilayer closure is necessary. Tissues should be passively approximated to be sure that the wound is closed without tension. There is a tendency for wounds closed under tension to tear open or necrose around the suture, risking infection or unnecessary scars. If the tissue cannot be approximated without tension, tissue can be undermined to give additional mobility to the skin edges. It is most often necessary with lacerations of the skin and attached gingival, or when there has been some avulsion of tissue. This tends to be less necessary with lacerations of non-keratinized mucosa in the oral cavity since the mucosa is normally mobile and not fixed in position.
For surface closure of facial and oral lacerations, generally interrupted sutures are placed instead of continuous sutures. They have the advantage of being strong and they can be placed as needed for individual situations. Loosening of one suture will not affect the entire wound.
A square knot is generally the knot of choice with interrupted sutures. It is formed by wrapping suture material around a needle holder once, tightening the tie, and then wrapping the suture material in the opposite direction and tightening the knot. With some materials, such as silk, a regular square knot is enough; however, materials such as nylon, polypropylene, polyglycolic acid, and polyglactin require additional ties to remain tied. A surgeon's knot is useful in areas where the first tie would be loosened while producing the second tie. Formed by taking two or three wraps of suture material on the first tie around the needle holder and then one loop in the opposite direction on the second tie, a surgeon's knot allows the first tie to stay tight while the second is being tied. A third or fourth tie can be made, alternating directions of the wraps, for additional security with difficult materials.
Sutures should be placed at an equal depth and distance on either side of the laceration and about 3 to 4 mm apart. With lacerations over areas of muscular action or increased tension, such as the tongue, sutures may need to be spaced closer. Sutures should be tied tight enough so that the tissue is approximated, but not blanched. The knot is placed to one side of the laceration, not over the line of incision. Properly placed, interrupted sutures should be placed in such a manner as to produce a slight eversion of skin margins. As scar contraction occurs, the skin will align to the proper level instead of leaving a depression.
Proper alignment of the tissues before suturing is necessary to avoid distorting tissues while suturing and to avoid causing extra tissue, space, or "dog ears" at the end of the wound. This can be accomplished by starting from a known position. For example, in a straight laceration, tissues are approximated and the first suture placed in the center of the wound. The next suture is placed to bisect the remaining segment on each side, continuing until the wound is closed. In the case of lacerations of the lip or gingival, sometimes a known landmark should be sutured first, such as the vermillion border, corner of the mouth, or gingival attachment to a tooth.
When placing sutures, grasp the needle about 3/4 of the distance from the point. Grasping any closer to the suture material may cause breakage of the needle since the eye or the hollow area where the suture material is swaged to the needle is the weakest part of the needle. The needle should enter perpendicular to the skin or mucosal surface in order to avoid tears of the tissue. The curve of the needle should be followed as the needle is passed through the tissue to avoid tearing tissue. When one side of the laceration is fixed and the other side loose, the needle should be passed from the loose side to the fixed side. When one side is thinner than the other, the needle should be passed from the thinner to the thicker side.
For deeper wounds, closure of muscular or subcutaneous layers is required before the closure of the skin or mucosa. Absorbable 4-0 material is used for this subcuticular layer. Individual interrupted sutures are easiest to place, although a continuous subcuticular suture is sometimes used with skin lacerations and incisions. When subcuticular sutures are placed, care must be given to align tissues properly so that the final surface wound will be aligned. When improperly placed subcuticular sutures distort the underlying tissues, the skin surface will not be able to be aligned without tension and distortion. Interrupted subcuticular sutures should be placed so that the knot is buried on the deep side of the suture.
Intact skin is one of the mechanisms that the body has to protect against injury and invading microorganisms. Once the skin barrier has been penetrated, as with a laceration, the protective responses of inflammation and immune responses are activated in the underlying connective tissue. Inflammation is a nonspecific local response that develops rapidly to limit the damage to the site of injury. The immune response takes longer to develop and is specific to the particular microorganisms and foreign proteins.
All injuries will lead to an inflammatory response by the body. Acute inflammation in the connective tissue produces the four symptoms of inflammation: heat, redness, swelling, and pain.
Inflammatory chemicals in the nearby tissue fluid are released in response to the initial injury. Sources of these inflammatory chemical mediators include the injured-tissue cells, macrophages, mast cells, and blood proteins. They signal surrounding blood vessels to dilate, increasing the flow of blood to the site of injury. This increased blood flow causes the redness and heat that is present with inflammation. Histamine and other inflammatory chemicals increase capillary permeability. This allows large amounts of fluid to leave the capillaries and accumulate as fluid in the surrounding connective tissue. This fluid, called edema, causes the swelling present with inflammation. Pain associated with inflammation is due to the excess edema pressing on nerve endings. Inflammatory chemicals present in inflammation also affect the nerve endings directly, causing some of the pain.
Although causing the symptoms that bother the patient, inflammation is beneficial to wound healing. The blood-derived fluid that accumulates in the connective tissue brings the oxygen and nutrients needed for wound repair from the blood to cells in the injured area. It also dilutes the toxins that are produced by foreign bacteria and transports antibodies from the blood to combat infection.
When injuries sever blood vessels, the fluid permeating from capillaries contains proteins to promote clotting. Occurring in the matrix of the connective tissue, clotting stops bleeding and isolates the injured area, blocking and preventing the spread of infectious microorganisms.
Stasis is the next stage of inflammation. In this stage, local blood flow slows down causing a massive transfer of fluid from the capillaries to the surrounding tissue. White- blood cells, initially neutrophils closely followed by macrophages, extrude from the dilated capillaries. Damaged-tissue cells and infectious microorganisms are consumed and eliminated by these cells.
Repair of the wound proceeds even as inflammation is present. Tissue is repaired by regeneration and by fibrosis. Skin or mucosal wounds heal with both regeneration and fibrosis. Regeneration is the replacement of the injured tissue by new cells of the same type, while fibrosis is the replacement of injured tissue by fibrous-connective tissue. This is the scar seen after wounds have healed.
After clotting has occurred within the wound and the clot dries forming a scab, wound repair continues with a process called organization. This is where the clot is replaced by granulation tissue, a delicate, vascular tissue that contains capillaries that grow in form adjacent areas and fibroblasts that produce collagen fibers. Some of the fibroblasts have contractile properties, pulling the margins of the wound together. The original clot is devoured by macrophages as organization of the wound continues and more collagen is deposited by fibroblasts. The granulation tissue gradually becomes more fibrous, forming the scar.
While organization is occurring, the surface epithelium of the skin or mucosa regenerates underneath the scab to cover the granulation tissue. When it has fully regenerated, the scab falls away, leaving an epithelium-covered surface with an underlying fibrous scar. It takes about one week for the complete regeneration of skin or mucosal epithelium.
In severe wounds, epithelium does not regenerate all the way across the wound, leaving fibrotic-scar tissue to replace the lost tissue. This scar has a shiny, pale appearance consisting mostly of collagen fibers with few cells or capillaries. While strong, it does not contain the flexibility or elasticity of normal tissue and cannot replace the function of the lost tissue. Scars tend to shrink and fade over several months following an injury.
Immune reactions are the method the body uses to fight infectious microorganisms introduced into traumatic or surgical wounds of the skin and mucosa. The immune system recognizes and destroys specific foreign molecules. It does this through white- blood cells, lymphocytes. Each lymphocyte recognizes its own type of foreign-body molecule called an antigen. B lymphocytes and T lymphocytes each flow throughout the vascular and lymphatic system continuously so they are available immediately at a wound site. Antibodies are produced and released by B lymphocytes, while cytotoxic T lymphocytes penetrate membranes of antigen-bearing microorganisms and induce programmed cell death.
The rate of wound healing and return of tensile strength depends on the deposition of collagen on the surfaces of wounds, sealing of the skin edges by regeneration of the epithelium, and revascularization of the blood vessels across the wound. Five days are required for collagen formation to be strong enough to afford strength to the healing wound. The skin edges require 2 to 4 days for bridging of epithelial cells. Four days are required for revascularization to occur so that blood vessels cross the wound, communi cating with blood vessels on the other side. At 10 days after repair, the strength of the wound is only about 10% of the pre-injury tensile strength. It is only 25% of the original strength at 21 days post-injury.
Sutures are used to hold together tissues that have been traumatically or surgically severed until the healing process provides the strength needed to hold the wound together. Understanding the physical and biological properties of materials used in suturing is important in wound healing.
Made of stainless steel or carbon steel, needles are available in either straight or curved shapes. Curved needles are used almost exclusively in dentistry, either for intraoral or skin use. The thickness and curvature varies among manufacturers. Standard curvatures are 1/4, 3/8, 1/2, and 5/8 of a circle.
Needles are either tapered or cutting. Tapered needles are generally used for suturing internal structures such as muscle and fascia. Cutting needles are used for tissue such as skin, mucosa, and subcuticular. There are two types of cutting needles, conventional cutting or reverse cutting. The internal cutting surface of conventional needles has one of the three cutting edges, while the internal cutting edge of reverse cutting needles has two of the cutting edge forming a flat internal surface.
Suture material is attached to needles in one of two ways. The most commonly used today is swaged in which the suture material is inserted into the hollow end of the needle when it is manufactured. The other type is a needle with an eye designed to have suture material tied to the needle. Swaged needles are not reusable. Needles with eyes are reusable, although the necessity for an eye makes the end larger and, therefore, leaves a larger hole. Swaged needles are more expensive than eyed needles; however, they are sharper, have superior working qualities, and are easier to use.
Ideal-suture materials have adequate strength to hold the wound together, good handling and knot-tying ability, provoke little-inflammatory reaction from the tissue, and are able to be sterilized.
|Figure 12 : A variety of absorbable and nonabsorbable sutures should be available to treat lacerations of the oral cavity and face.|
Sutures are sized by number. No. 3 is the largest, and the smallest in general use is 7-0. More zeros in the number indicate a smaller diameter of the strand. Sutures of 3-0 and4-0 are generally used in the oral cavity, while smaller diameter 5-0 or 6-0 are used for skin lacerations of the face.
Materials for sutures are categorized into two broad groups: absorbable and nonabsorbable. In both categories, sutures are either biologically derived or synthetic.
Absorbable sutures are used for temporary purposes, such as subcutaneous use where they will not be removed. Degraded by enzymes and phagocytes or by a hydrolytic reaction, absorbable sutures lose strength over time and dissolve. They are absorbed more rapidly in tissues rich in vascular tissue, for example, subcutaneous tissue than in less vascular tissue, for example, fascia.
Sutures that are absorbable are either derived from biological material or synthetic materials. Considerable tissue reaction and inflammation are present with sutures that are biologically derived, such as plain-gut or chromic catgut, than with synthetic-absorbable sutures, such as polyglycolic acid (Dexon) or polyglactin (Vicryl). This is because biologically derived sutures evoke a phagocytic reaction with the production of exudative fluids that delay healing. Synthetic materials dissolve via a hydrolytic mechanism that does not provoke an inflammatory reaction.
The oldest-known suture material is gut, derived from bovine-intestinal serosa or sheep- intestinal submucosa. Plain-gut suture is made of several plies of tissue that have been slightly twisted, machine ground, and polished to provide a smooth surface. It appears to be monofilament, although it is not.
Plain gut has the least tensile strength of absorbable sutures. Grinding and polishing during manufacturing provide a uniform diameter which, however, also produce weak areas. As such, gut sutures have a tendency to break while being used. Gut suture is packaged in isopropyl alcohol since it is a biological material subject to organic degradation. Tensile strength is rapidly lost when placed in a patient, with only 20% of strength remaining after 2 weeks. Used for deep closure of wounds, plain gut can last 40 to 60 days before it is totally absorbed; while used intraorally it lasts for 3 to 5 days.
Chromic-gut suture material is plain gut that has been treated with a solution of chromium salts to increase tensile strength and reduce absorption by the body. While chromic gut may last 80 days when buried deep in a wound, it is usually degraded within 7 days when used in the mouth.
Plain-gut and chromic-gut sutures are absorbed by the body, both by phagocytosis and proteolytic degradation, accompanied by considerable inflammatory reaction.
Polyglycolic acid (Dexon) or polyglactin (Vicryl) are common synthetic-absorbable sutures. They produce very little tissue-inflammatory reaction because they are synthetic polymers that are degraded by hydrolysis.
Polyglycolic acid is a high-molecular-weight polymer produced by exposing hydroxyacetic acid to heat and a catalyst. Polyglactin is a copolymer of glycolide, derived from hydroxyacetic acid, and lactide, derived from lactic acid. Filaments of these polymers are stretched and braided to form suture material.
Synthetic-absorbable sutures will last in subcutaneous tissues for 4 months and in the oral cavity at least 14 days. Inflammatory-tissue reactions are minimal, with some studies showing that degradation products inhibit bacteria, thereby minimizing inflammation.
Nonabsorbable sutures may be biologically derived natural materials or synthetic materials. Silk and cotton are examples of biologically derived suture materials and nylon, Dacron, polypropylene, stainless steel, tantalum, and titanium are examples of synthetic materials.
Silk is an organic material that is the most commonly used suture in the oral cavity. It is classified as a nonabsorbable material and it is so for all practical purposes in dentistry. It does slowly dissolve by proteolysis over a 2-year period, which is longer than it would be used for any oral or facial use.
Braided with excellent handling characteristics, silk sutures are inexpensive and do not cause inflammation in adjacent mucosa. It initially produces more inflammatory-tissue response than nonabsorbable-synthetic material; however this evens out at about 7 days. Silk has low tensile strength, slightly above gut and it is easy to use in the oral cavity.
Nylon is a popular suture for closure of skin wounds. It is not commonly used in the oral cavity, as it tends to tear through nonkeratinized mucosa, is more expensive, and more difficult to use than silk, Dexon, or Vicryl. The cut ends of the knot are not flexible and are irritating to the patient when used in the mouth.
Available as braided or monofilament suture, monofilament nylon is the most popular suture. Inflammatory tissue reaction is minimal with nylon sutures, partially due to the antibacterial properties of degradation products of nylon. Tensile strength is good.
The extruding and stretching of the nylon polymer during manufacturing gives nylon sutures a "memory." They have a tendency to try to remain straight and knots tend to untie, making nylon sutures more difficult to work with. Multiple square knots are tied when using nylon sutures to prevent untying.
Dacron, polypropylene, and sutures of similar materials are braided which provide high tensile strength and good retention of a tied knot. Inflammatory tissue reaction is minimal.
Metal sutures are made of stainless steel, tantalum, or titanium and are used in some situations, such as scar revisions in patients who tend to form keloids. They are not used in dentistry.
For the first 4 to 7 days, the reaction by the body to sutures is about the same regardless of the suture material used. An inflammatory reaction occurs due to the intrusion of the tissue by the needle. This reaction is set off by the trauma caused by the needle, even if no suture material is present.
Inflammation occurs in response to the initial injury. Inflammatory chemical mediators, including the injured-tissue cells, macrophages, mast cells, and blood proteins, signal surrounding blood vessels to dilate, which increases the flow of blood to the site of injury and causes the redness and heat that are present with inflammation. After a few days, leukocytes, monocytes, macrophages, and fibroblasts are present.
The tissue response after 4 to 7 days is related to the suture material used. An intense response is seen to biologic-absorbable material, such as plain gut, with an abundance of neutrophils and macrophages. Nonabsorbable-suture material provokes a less intense response. When suture material is used for skin or mucosal closure, for 5 to 7 days epithelial cells will track down the suture pathway. The epithelial cells will track farther down the suture track the longer the suture is in place and will remain after removal of the suture. They may form inclusion cysts, form keratin, or disappear. Suture scars, the so-called "railroad track," that sometimes remain after sutures are removed are due to the growth of the epithelial cells into the deep tissues along the path of a suture.
In addition to epithelial-cell growth, sutures form a path for bacteria on the skin to travel, gaining access to deeper tissues. Removing sutures as soon as possible helps prevent such infections. Typically, skin sutures on the face are left in place 3 to 5 days, while intraoral sutures are removed in 5 to 7 days. Other skin sites, especially those that are under tension or over joints, are left in place 5 to 10 days.
Most facial lacerations seen in the dental office in association with injured teeth or jaws will be relatively minor. Lacerations that are more involved are usually noticed in the field and the patient is brought to an emergency room of a hospital for repair. Oral lacerations may or may not be obvious to the patient before examination by the dentist. Often, a displaced tooth is noticed and the patient is brought to the dentist who upon full examination will notice extensive lacerations of the oral mucosa or tongue.
The general rule of thumb in the repair of facial injuries is "inside, out," i.e., dental injuries and oral lacerations are treated before facial lacerations, to avoid tension on or tearing of repaired lip or facial lacerations. This may not always be possible if the patient's facial lacerations were first treated in an emergency room prior to referral to the dentist.
Generally, an absorbable suture, such as 4-0 Vicryl, Dexon, or gut is used for lacerations of the oral mucosa and tongue. These suture materials can be used for deep muscle repair as well as wound surface closure. Silk sutures can be used, but they need removal, which can be difficult if they become buried around swollen or inflamed tissue. Nylon materials are not acceptable, as they need removal and the straight ends of the knot retain their memory and stick up, "poking" the patient and irritating any tissue that may rub against them.
For skin lacerations, 4-0 Vicryl or Dexon sutures can be used for muscular and subcuticular closure, when necessary. Nylon or Dacron sutures are placed in an interrupted fashion for surface closure of the laceration. Generally, 4-0 or 5-0 sutures are used for skin around the lips and face. Delicate skin, such as around the eye, may require 6-0, but the small size of the needle and suture material make these difficult to work with and to remove.
After skin wounds are sutured, they should be covered with an antibiotic ointment and can be covered with a nonadhesive dressing, such as Telfa, which is taped in place. Antibiotics and tetanus toxoid are appropriate for potentially contaminated wounds.
Sutures in the skin of the face are removed in 3 to 5 days to avoid "railroad track" suture scars caused by epithelial growth along the suture tract. When they are removed, Steri-Strips or similar skin tape can be placed to continue to hold the wound together while the wound continues to heal and gain tensile strength.
Certain types of lacerations require special considerations. These include tongue lacerations, lip lacerations, and "de-gloving" type lacerations.
|Figure 14 : Repaired laceration, requiring suturing of the muscle layers and the ventral and dorsal mucosa using absorbable sutures. Also note the repaired facial laceration.||Figure 13 : Laceration of the tongue caused by a motorcycle accident. The wound extends all the way though the ventral surface, muscle, and dorsal surface.|
Tongue lacerations occur when the tongue is lacerated by a foreign body or is bitten by the patient during an injury. Sometimes tongue lacerations along with injuries to the teeth and alveolus occur when a well-meaning person tries to force something between the teeth while the patient is having a seizure.
The tongue is composed of extrinsic muscles and intrinsic muscles. The genioglossus, hyoglossus, and styloglossus muscles are extrinsic muscles and they are responsible for the protrusion, retraction, and lateral movements of the tongue. They are deep inferior to the intrinsic muscles and are infrequently lacerated. The body of the tongue consists of intrinsic muscles that change the shape of the tongue without changing its position. They are arranged in groups of fibers that run in several different planes. From superior to inferior, the intrinsic muscles include the superior-longitudinal muscle, which runs anterior to posterior, a band of transverse muscle running right to left, a band of vertical muscles, another band of transverse muscle, and the interior-longitudinal muscle running anterior to posterior. The tongue is divided down the middle by a band of connective tissue, the median septum, and both halves contain identical bands of muscle. It is not necessary, or generally possible, to clinically identify the various bands of intrinsic-muscle fibers when repairing a tongue laceration.
The lingual frenulum is a fold of mucosa on the inferior surface of the tongue that secures the tongue to the floor of the mouth and limits posterior movements. It is sometimes lacerated from foreign bodies or mandibular-anterior teeth. Arterial blood supply is from bilateral-lingual arteries. The tongue is extremely vascular and bleeds profusely when lacerated.
Superficial lacerations of the mucosa or muscle are sutured in the standard method using absorbable-interrupted sutures. Full-thickness lacerations should have multilayer closure. This can be accomplished in several ways. The easiest is to close the mucosa on the inferior aspect of the tongue, followed by the muscular layer, and then the mucosa on the superior surface.
Isolated lacerations of the lingual frenulum are sutured or not, depending on the severity of the laceration. These lacerations generally do not require repair unless they are extensive.
Lacerations of the lip may be superficial, involving only the mucosa or only the skin, or they may be more complex full-thickness lacerations that cut through skin, muscle, and mucosa. Lip lacerations can be closed without tension even if there is significant avulsion of tissue.
Simple lacerations of the skin or mucosa are treated with cleansing, debridement, hemostasis, and closure with interrupted sutures. Full-thickness lacerations must have multilayer closure. Repairs should always begin by closing the mucosal side first with absorbable sutures, such as 4-0 Dexon, Vicryl, or gut. Following this the muscular layer is closed using absorbable sutures, taking care to properly approximate the segments into normal position. Sutures should not be tied so tightly that they cause bunching of the tissue.
If the vermillion border is involved, it is crucial that it is lined up properly or the cosmetic result of the healed wound would be poor. Temporary placement of a suture through the skin to align the vermillion border helps greatly in the accurate approximation of the muscle layer. Once the muscular layer and subcuticular layers are sutured, the skin may be sutured with an interrupted-suture technique using nonabsorbable sutures, such as 4-0 or 5-0 nylon. The wound is covered with antibiotic ointment.
A de-gloving type of laceration is a laceration that pulls the mucosa and periosteum off the bone. It typically occurs in the labial aspect of the anterior mandible from injuries in which the patient falls with a heavy impact that pulls the lip down. Falling over the handlebars of a bicycle and landing on pavement is a common way to do this. As the lip strikes the ground and stops while the head continues, the gingiva pulls away from the teeth along with the underlying periosteum. The periosteum is often traumatically dissected all the way to the inferior border of the mandible, exposing the labial bone and bony chin. Sometimes this type of injury will extend laterally to expose the mental nerves.
Often a de-gloving injury is not immediately apparent. When the lip goes
back to its
normal position as soon as the patient stands up, the mucosa and periosteum are in a fairly normal position. Only the laceration of the gingival tissues is noticed at first. When the lip is retracted upon examination, however, the full extent of the injury is immediately evident.
Since the mechanism of this type of wound is face against the ground, these wounds are frequently contaminated with extensive amounts of dirt, gravel, grass, and other debris. They need to be meticulously debrided of all foreign materials and then irrigated well. Once the wound is clean, the repair is generally straightforward. The tissue is repositioned and often all that is necessary is to suture the labial-interproximal gingiva to the attached lingual-interproximal gingiva with interrupted sutures, similar to reattaching a periodontal-surgical flap.
The patient should be placed on antibiotics and the patient's tetanus-toxoid status checked. If the mental nerve was visualized, the patient should be warned of the possibility of long-term anesthesia or paresthesia of the lip and chin.
: Laceration of the lip extending through the vermillion border and
through muscle and oral mucosa.
||Figure 16 : Repaired lip laceration. After temporary alignment of the vermillion border, absorbable suture is used to suture the oral mucosa, followed by the muscle and subcuticular layers. Finally, the skin is sutured using nonabsorbable sutures.|
Extending from the upper region of the body of the mandible, the alveolar process is the portion of the bone that supports the teeth. It is subject to fracture due to traumatic injuries, which are particularly common in the anterior mandible and anterior maxilla. The fracture may or may not involve an alveolar socket and tooth.
Alveolar-process fractures may occur as isolated fractures or in conjunction with complete fractures of the mandible. Isolated alveolar-process fractures occur due to a direct blow to the alveolus. Common causes include violence, motor-vehicle accidents, bicycle accidents, and sports injuries. Usually, direct blows to the teeth are the cause of alveolar-process fractures; however, direct blows to the alveolar process itself can cause fractures. When the teeth sustain a force that forces them posterior and they are not displaced from their sockets, the roots are forced anterior fracturing the thin alveolar bone in the process.
Multiple teeth are usually involved in fractures of the alveolar process in the anterior mandible. Often, the fracture involves four teeth, the two central incisors and the two lateral incisors. Occasionally, the mandibular–cuspids are also included in the fractured segment. These large, tooth-bearing segments may be displaced with adjacent tissue attached or may be totally avulsed, tearing them from their soft-tissue attachment.
Alveolar-process fractures of the anterior maxilla are caused from direct blows to the teeth or alveolus from an anterior or lateral direction, or from an upward blow to the mandible, such as when the chin is sharply forced against the chest, steering wheel, or other such object. In the maxilla, fractures of the alveolar bone may involve only one tooth or multiple teeth. The maxillary-central incisors and/or the lateral incisors are most often the teeth involved. Maxillary cuspids can also be involved, but this is not very common. It is rare that bony segments of maxillary-alveolar fractures will be completely avulsed. Tissue usually remains attached to the bone, especially the palatal tissue.
Fractured segments of either mandibular- or maxillary-alveolar processes may contain fractured teeth or fractured roots in addition to fractures of the bone. The injuries to the teeth must be considered in the total treatment plan. Damage to the neurovascular supply of the teeth or to the periodontal ligament is possible, resulting in pulpal necrosis, a common occurrence, or external inflammatory resorption of the root, a rare occurrence.
In severe injuries, especially from high-speed motor-vehicle accidents, segments of fractured-alveolar process may be completely avulsed and displaced into the soft tissues of the floor of the mouth or tongue. Any puncture wounds or lacerations of the lips, tongue, mucosa, or floor of the mouth that are found in conjunction with missing alveolar segments or teeth should be thoroughly examined for fragments of teeth, bone, or other foreign bodies.
Fractures of the posterior segments of the mandibular- or maxillary-alveolar process are possible, but rare. They are usually caused by a severe force, such as in motor-vehicle accidents. In most cases, this force will fracture the entire mandible through the inferior border and not just the alveolar process.
Iatrogenic causes are another source of alveolar-process fractures, especially common in the posterior segments secondary to extractions of teeth. Extraction of a tooth requires some displacement of alveolar bone. While generally performed by controlled force, when resistance is encountered a dentist may apply excessive force to achieve mobility and fracture the alveolar process. This is most common when removing a single maxillary first or second molar that is solitary with no other teeth immediately adjacent. Buccal bone in this area may be very dense due to the proximity of the zygomatic process (buttress) of the maxilla. The roots of the tooth may be in the maxillary sinus, giving no bone support. Excessive force during extraction may fracture the dense cortical plate on the buccal, and the tooth and bone may be removed as a unit, leaving an exposure into the sinus. Other times, the entire alveolar process in the area may fracture along with the tooth. This is most common with removal of solitary second or erupted third molars. The tooth remains solidly intact within the mobile alveolar process.
|Figure 17: Displaced fracture of the maxillary alveolus containing teeth # 9 and #10. After reduction, such a fracture can be stabilized with an arch bar or semi-rigid splint.|
There will be a history of an injury or impact in traumatic causes of fractures of the alveolar process. The patient may complain of displacement or loosening of the bone, teeth, or of malocclusion. Pain, bleeding, and swelling of adjacent lips or tissues may be present, as may soft-tissue lacerations of the lips, gingiva, tongue, or floor of the mouth.
In the case of iatrogenic fractures of the alveolar process during extractions, the patient will have few or no symptoms since the region is anesthetized with local anesthesia; however, the injury should be readily apparent to the dentist.
Clinical examination shows mobility of the alveolar segment. Teeth within the fractured segment are usually solid within the mobile fractured segment. The segment may be displaced and locked solidly into the new position. Clots or evidence of bleeding may be present, and gingival or mucosa lacerations are common. Percussion of the teeth produces a dull sound.
On examination, it is important to determine that the fracture is limited to the alveolar process and does not go through the inferior border of the mandible or entire maxilla. A mistake often seen in emergency rooms is to examine a mobile anterior maxilla and conclude that it is an alveolar fracture, when in fact the entire maxilla moves due to a complete Le Fort I type of fracture of the maxilla.
Lacerations of the adjacent gingiva, mucosa, and lips are common. Lacerations of the tongue and floor of the mouth are less common.
Radiographic appearance of an alveolar fracture is variable, depending on the angle of the central x-ray beam. Vertical fractures on the medial and lateral sides of the fractured segment may be seen. Horizontal fractures may be seen in various locations from the cervical region to the periapical region and may be superimposed over the roots. Determination needs to be made whether this is only a fracture of the alveolus or whether the roots are also fractured. Taking another radiograph after changing the angulation of the central x-ray beam will not change the location of the vertical fracture line of a root fracture, but will move the fracture line of an alveolar fracture superior or inferior in relation to the root surface.
While radiographs are preferable prior to treating an alveolar fracture, there are times when periapical or panoramic radiographs are not available, such as when the patient is treated in an emergency room of a hospital. In such cases, the alveolar process fracture can be reduced and stabilized based on clinical examination and periapical radiographs taken at a later date.
Under local anesthesia, the displaced segment of the alveolar process and teeth are repositioned into normal anatomical alignment. Apices of involved teeth may be locked against adjacent bone and may need to be disengaged. Usually, displaced segments can easily be repositioned, although considerable force is sometimes needed.
|Figure 18 : Rigid fixation used to stabilize a displaced alveolar fracture of the maxilla.||Figure 19 : Displaced segment of fractured alveolus lying on tongue, attached by a small amount of lingual gingiva.|
|Figure 20: Segments of alveolar fractures that have no blood supply from soft tissue will not reattach to the bone and should be removed.|
Once repositioned, the fracture is stabilized for 3 to 4 weeks using a rigid splint, such as an Erich-arch bar, or a semirigid wire and resin splint. The splint is attached to several stable teeth on either side of the fracture and then to the teeth in the fractured segment. When an arch bar is used, a 24-gauge stainless steel wire is placed circumdentally around each tooth.
Small fragments of bone not attached adequately to soft tissue will necrosis if left in place and, therefore, should be removed. Large segments of alveolar bone that have adequate blood supply from tissue attachment may be positioned in contact with adjacent bone. After debridement of the wound and reduction and stabilization of the fracture, any gingival or other soft-tissue lacerations are sutured.
The occlusion should be checked to make sure no hyperocclusion of the teeth in the injured segment is present. If it is there, selective grinding to adjust the opposing occlusion is advisable.
As this is an open, contaminated wound, the patient should be placed on antibiotics for 7 to 10 days. Prescription analgesics are advisable. Home-care instructions include a soft diet, avoiding biting down on the injured teeth. Ice packs may help to reduce soft tissue swelling of the lips that often occurs with such injuries.
After the splint is removed, the teeth should be monitored for vitality and external inflammatory resorption. They should be examined at 1, 3, 6, and 12 months after the injury and annually thereafter. Check for signs of pulpal necrosis or external inflammatory resorption with radiographic and clinical testing, including evaluation of the color of the crown, percussion, palpation, mobility, and electric- and cold-vitality testing.
Fractures of the mandible and the facial bones (maxilla, zygoma, and nasal bones) are often seen in association with injuries to the teeth and mouth. While most dentists in general or specialty practice will not usually be treating these types of injuries, they will see patients with them. The chapters on mandible fractures and facial fractures are provided in order that all dentists who see dental injuries are able to diagnose facial fractures in their patients and provide immediate care until the patient is referred to the treating surgeon. Also, an understanding of the treatment and long-term consequences of the injury is helpful in providing continuing care after the fractures have healed.
The location and prominence of the mandible within the facial skeleton make it susceptible to trauma. It is not surprising that it is the most commonly fractured bone in the facial skeleton. About two-thirds of the fractures occurring to the facial bones involve the mandible.
Early historical reports often mentioned mandible fractures, but rarely midface fractures. The mandible tends to fracture when subjected to severe impact, while the midface has more ability to dissipate the force before fracturing. It takes a much more severe injury to fracture the midface than the mandible. Until World War II, mandible fractures were far more common than midface fractures. After World War II, the number of midface fractures increased due to high-speed transportation.
Fractures of bones may occur from a variety of causes and are somewhat age-related. Very young children have bones that are pliable and flexible, requiring severe force to cause a fracture. In young people, fractures commonly occur from falls, motor-vehicle accidents, sports injuries, and violence.
As the bones thin and weaken with old age, falls and motor-vehicle accidents are common causes. The alveolar process disappears due to disuse atrophy when teeth are extracted. In isolated areas of extraction, the atrophy of the alveolar-process bone weakens the mandible, making it more susceptible to complete fracture of the mandible through the inferior border. When a patient is completely edentulous, the extensive atrophy of the alveolar process predisposes the mandible to fracture from minor trauma.
|Figure 22 : To place arch bars and intermaxillary fixation, wire cutters, wire twisters, Erich-arch bars, and 24-gauge wire are needed.||Figure 21 : Intermaxillary fixation is used to treat fractures of the mandible. Erich-arch bars are placed on the maxillary and mandibular arches, the fracture is reduced, the patient brought into occlusion, and intermaxillary wires placed to stabilize the fracture.|
|Figure 24 : Panoramic radiograph of the same patient with displaced fractures of the right parasymphysis and left body of the mandible.||
: Intraoral view of displaced fractures of the right parasymphysis and left body of
Bone is a complex material containing organic and inorganic components. Organic components, including cells, fibers, and ground substance, account for 35% of the mass of bone and contribute to its growth, flexibility, and tensile strength. The major portion of the extracellular matrix of bone is collagen, present in the form of long, highly oriented strands. Other protein mucopolysaccharides and lipids make up most of the other extracellular components of bone. The inorganic components, consisting of small crystals of hydroxyapatite and calcium phosphate, are infused within the densely packed collagen fibers and account for 65% of bone mass.
When a bone is fractured, a several-week period of healing begins. Four physiologic phases of healing occur during this time: hematoma formation, fibrocartilagenous callus formation, bony callus formation, and bone remodeling.
When a bone fracture occurs, there is a rupture of the blood vessels of the bone marrow, cortex, periosteum, and surrounding tissues and muscles, causing hemorrhage. The blood released from torn blood vessels clots, forming a hematoma within 6 to 8 hours from the time of injury. The hematoma completely surrounds the ends of the fractured bone, bone marrow, and surrounding tissues. Inflammation develops along the site of the hematoma. These inflammatory cells digest fragments of bone, bone marrow, periosteum, muscle, and connective tissue that may have been incorporated into the hematoma. This phase occurs during approximately the first 10 days following the injury and the reduction of the fracture.
Within 24 to 48 hours, new-blood vessels grow into the clot and there is a proliferation of fibroblasts and osteocytes in the periosteum and endosteum adjacent to the fracture site. These cells then grow into the clot and form a primary callus, also known as a soft callus. This soft callus is initially a fibrous granulation tissue that then is transformed into a dense connective tissue callus containing fibrocartilage and hyaline cartilage, called a fibrocartilagenous callus. The primary callus consists of an anchoring callus, developing near periosteum and forming osteoblasts, a sealing callus, developing on the inside surface of the fractured bone, and a bridging callus, forming between the fractured ends.
Endochondral ossification occurs in the callus within a week and new bone begins to form. The trabeculae grow until they span the width of the fracture to join the two fragments. This is known as a bony callus or a hard callus. The bone consists of laminated bone able to withstand active use, but does not have the Haversian structure of mature bone. It is heavily calcified and can be observed on radiographs. For about 60 days, the trabeculae grow stronger and thicker until the fracture is completely healed, replaced with new bone.
Over a period of months or years the bony callus is remodeled by functional reconstruction. Mechanical forces on the bone remodel the new bone into the pattern of the original unbroken bone. Functional use molds the shape of the bone, removing bone from one surface and adding it to another. Excess bone material is removed and needed bone is added to reconstruct cortical and medullary bone.
|Figure 25: Placement of 24-gauge wires to temporarily stabilize the fractures while patient is awaiting transportation or being treated for more serious injuries.||
: Panoramic radiograph of displaced angle fracture of the mandible. Angle fractures
frequently occur through the region of an impacted third molar.
There are any number of causes for fractures of the mandible, including falls, sports injuries, fights and violence, motor-vehicle accidents, industrial accidents, horseback-riding injuries, and gunshot wounds.
Most fractures of the mandible are caused by external force, such as a blow to the jaw. These may be due to a direct force substantial enough to cause a fracture directly at the site of impact, or due to an indirect force. With an indirect force, the impact is to a site other than the fracture. The force is transmitted and the bone bends, fracturing at the weakest point if the elasticity of the bone is surpassed. For example, when a person falls on his or her chin, the person may sustain a direct force fracturing the symphysis, but more than likely the force will be transferred posteriorly causing an indirect fracture of the weakest point one or both necks of the condyles. Another common indirect fracture is the fracture of the condylar neck on the opposite side from a blow to the angle of the mandible.
Internal muscular force can also cause fractures of the mandible. For example, an electrocution can cause violent contraction of the muscles fracturing teeth or the mandible. Bone weakened due to cysts, neoplasms, or removal of third molars may fracture during chewing.
Bone disease may predispose the mandible to fractures from external or internal forces. Hyperparathyroidism, osteomalacia, osteoporosis, and other generalized bone diseases may change the density and form of the mandible making it more susceptible to fracture. Local-bone diseases, such as cysts, benign neoplasms, malignant or metastatic neoplasms, may weaken bone, as may recent surgery. Such fractures are called pathologic fractures. Fractures of the angle of the mandible are common through areas of bone weakened by impacted third molars.
Anatomic considerations of areas likely to fracture include thin regions in the angle or neck of the condyle. Often the area at the junction of weak and strong portions of the mandible is the area that will fracture. Edentulous areas in which there has been significant atrophy of alveolar bone are predisposed to fracture. Weaker anatomical points, such as the area of the mental foramina, are areas where fractures occur more frequently.
Fractures of the mandible are classified in several ways, including location, type of fracture, severity of fracture, and the direction or displacement of fracture.
Locations include fractures of the symphysis, parasymphysis, body, angle, ramus, coronoid process, and condyle. Symphysis fractures occur through the midline of the mandibular central incisor. Parasymphysis fractures occur between the midline and the mandibular cuspid. Body fractures are those that occur between the cuspid region and the angle of the mandible. Angle fractures occur behind the second or third molar and extend to the angle of the mandible. Ramus fractures occur between the angle of the mandible and the coronoid (sigmoid) notch. Coronoid-process fractures occur in the coronoid process above the level of the coronoid notch. Condylar fractures occur in the head or neck of the condyle, above the level of the coronoid notch. Fractures on the region of the neck of the condyle are also known as subcondylar fractures. While various studies show different statistics as to percentage of fractures in each location, all show that condyle, angle, and body fractures are the most common and that coronoid-process fractures are rare.
Classification by type of fracture describes the injury to the bone. Classifications include greenstick, complex, comminuted, impacted, and depressed fractures. With greenstick fractures, the bone is bent, resembling green stick that has been partially broken, but without separation of the fragments. A complex fracture is one in which the fracture is severe and is displaced in several planes and includes fractures that extend into a joint. Comminuted fractures are simple or compound fractures that have many fragments. Impacted fractures are ones in which the fragments are driven into each other. Depressed fractures show a depression or deformity in the bone, such as depressed-zygomatic arch or depressed-skull fractures.
The severity of the fracture simply describes whether or not the fracture communicates through the skin or mucosa. A simple fracture is defined as a fracture that does not have a wound or communication through the skin, even if the fracture is grossly displaced. If no laceration is present, a severely displaced fracture of the mandibular condyle is considered a simple fracture by this definition. A compound fracture is one in which there is communication between the fracture and the outside. Any fracture that had a laceration of the skin or mucosa that extends to the bone would be a compound fracture. It is important to recognize that any fracture that extends alongside a tooth is a compound fracture, as oral bacteria can percolate along the side of the tooth to the underlying bone. Antibiotics are generally prescribed for compound fractures, although fractures of the mandible seem to be less likely to become infected through wounds extending through the oral cavity than wounds that extend to the bone through the skin.
The muscle pull and direction of the line fracture determine whether or not the fracture will be displaced, and, more than anything else, determine the treatment. Fractures are classified as favorable or unfavorable depending on whether or not the direction of the line of fracture will allow the muscles to distract the fragments. For example, in a fracture of the body, if the fracture line extends from the inferior border in the molar region anteriorly to the bicuspid region, the fracture is unfavorable. The elevator muscles acting on the ramus (the masseter and medial pterygoid) will distract the fracture by elevating the posterior fragment away from the anterior fragment. If the fracture extends from the inferior border of the mandible in the bicuspid region to the retromolar region on the posterior alveolus, the fracture is favorable since the elevator muscles will pull the posterior fragment up into the anterior segment.
Most fractures of the mandible are described by a variety of terms using the location, severity, displacement, and type of fracture. Examples would be "displaced subcondylar fracture of the mandible," "non-displaced, compound parasymphysis fracture of the mandible," or "comminuted fracture of the body of the mandible."
|Figure 27 : Closed reduction with intermaxillary fixation of displaced angle fracture. Impacted teeth in the line of fracture should be removed.|
A detailed history of the injury is important in diagnosing fractures of the mandible. Circumstances of the injury including the direction of the force, the intensity of the force, and other details help in establishing what type of injury to consider in the differential diagnosis. A patient with a blow to the side of the mandible should be evaluated for fractures at the site of the impact and the contralateral-condylar region. With blows to the symphysis area, fractures of the necks of the condyles should be considered. The state of consciousness at and after the injury is important to evaluate the possibility of head or brain injuries.
Symptoms of patients who have sustained fractures of the mandible include pain, tenderness, swelling, ecchymosis, trismus, abnormal function, crepitus, malocclusion, anesthesia/paresthesia, excessive salivation, and fetor ex or.
Pain is usually present on movements of the mandible. Due to the injury of the bone, periosteum, inferior-alveolar nerve, or soft tissue adjacent to the injured site, it is usually present immediately after an injury. Condylar fractures should be suspected if there is pain in the condylar or TMJ regions that occurs with attempts to open the mouth
Palpation over a fracture site can cause severe tenderness over the fracture site.
Swelling can occur almost immediately after a fracture due to hemorrhage into the soft tissue adjacent to the site of fracture. It can be significant and can cause distortion of the facial symmetry, suggesting a fracture. Swelling can increase due to edema for several days following a fracture.
Bruising (ecchymosis) follows the hemorrhage or hematoma, causing red, blue, or purple discoloration of the skin and mucosa. Ecchymosis in the floor of the mouth or buccal gingiva and mucosa should suggest the possibility of a fracture.
Trismus due to pain on movement of the mandible causes a reflex spasm of the muscles that limits oral opening in an attempt to avoid pain. It is frequently seen with fractures of the ramus or angle of the mandible when the elevator muscles spasm. Patients may be unable to open their mouth and may avoid trying to chew.
Displaced fractures of the mandible may alter the function or range of motion of the mandible. When a displaced fracture of the mandible occurs in the subcondylar region the midline of the teeth may be deviated towards the side of the fracture. On opening or protruding the mouth the mandible will deviate towards the fractured side due to the lack of function of the lateral-pterygoid muscle.
When fractured segments of bone rub or move against each other during attempts to open or close the mouth, they may produce a grating or grinding sound called crepitus. Patients may report this in describing their symptoms. Crepitus may also be noted on physical examination with bimanual palpation of the mandible. It usually is associated with pain during bimanual palpation.
With displaced fractures of the mandible, one of the things patients notice first is a change to their occlusion. They will notice even a slight change to the occlusion and may complain they are unable to close their teeth together in the normal fashion.
Injury to the inferior-alveolar nerve may cause numbness (anesthesia) or tingling (paresthesia) to the lip and chin region. The nerve may be stretched, crushed, severed, or may have sustained other damage.
The salivary glands are stimulated to produce excessive saliva due to pain and tenderness at the fracture site. This excessive saliva along with pain on swallowing causes drooling.
Managing Dental Injuries
Foul-smelling breath, fetor ex or (fetor of breath), is caused by bacterial degeneration of food, blood clots, and mucous. It is quite obvious to the patient, family, and medical personnel.
The clinical diagnosis of a mandible fracture can be established if one or more of the following clinical findings is present: malocclusion, mobility of the fracture site, crepitus at the fracture site, or abnormal function of the mandible. In addition, while not pathognomonic for a mandible fracture, the presence of swelling, ecchymosis, lacerations, and fractures or displacement of teeth should give a high index of suspicion of the possibility of a fracture.
A change in the patient's occlusion is one of the most reliable findings of a displaced fracture of the mandible. When fractures occur through the teeth, the dental arch may be displaced. There may be separation between teeth, a step in the level of the occlusion, and mobility on swallowing. Bilateral condylar or subcondylar fractures may cause an anterior open bite. Posterior cross bites may be present with unilateral subcondylar fractures.
Movement of the bones at the fracture site to bimanual palpation is evidence of a fracture. This will also be accompanied by pain. Bimanual palpation of a greenstick fracture may not cause movement, but rather may elicit pain giving a high suspicion of a fracture.
Crepitus is grinding or grating that can be heard or felt during bimanual palpation of a mobile fracture site. Like mobility of the bone, it is pathognomonic for a fracture of the mandible.
Abnormal range of motion during function of the mandible is due to displacement of the bone fragments following a fracture of the mandible. Deviation of the occlusion on closing or deviation of the midline on opening is indicative of a fracture, although some midline deviations may indicate internal injury of the disc of the temporomandibular-joint rather than a fracture of the bone.
Mandible fractures are usually fairly easy to diagnose from radiographs. Specific radiographic views are used to examine various parts of the mandible.
A panoramic radiograph is an excellent screening radiograph and can show fractures in all areas of the mandible, including the condyles. Other views that are helpful include a PA skull or PA cephalometric view. Displacement of angle, ramus, or body fractures can be better visualized with this view than on a panoramic radiograph. Towne's views taken with the mouth wide open give good visualization of the condyle region when evaluating for fractures. They are a frontal view taken at right angles to a panoramic view. Hospitals often take oblique lateral views of the mandible to visualize the ramus and body. They are often insufficient to clearly show the condylar region and are not as diagnostic as a good panoramic radiograph.
Condylar head fractures, followed by subcondylar fractures, are probably the most missed fractures both clinically and radiographically, and are a common source of litigation. Clear views of the condyles are mandatory during a radiographic examination.
Separation of teeth
Misalignment of dental arch
Arch may be narrowed due to telescoping of fragments
Mobility of bone fragments
Ecchymosis of floor of mouth or labial gingiva and mucosa
Swelling of the floor of the mouth
Often associated with lacerations of the lip
Suspect possibility of unilateral or bilateral condyle fracture
Separation of teeth
Misalignment of dental arch
Arch may be narrowed due to telescoping of fragments
Mobility of bone fragments
Ecchymosis of floor of mouth or labial gingiva and mucosa
Managing Dental Injuries
Swelling of the floor of the mouth
Displaced bilateral parasymphysis fractures: anterior segment of
arch may be displaced inferiorly due to muscle pull and cause swallowing difficulty.
Separation of teeth
Misalignment of the dental arch
Mobility of bone fragments
Ecchymosis of the floor of the mouth or buccal gingiva and mucosa
Swelling of the floor of the mouth
Probable anesthesia or paresthesia of the lip and chin in displaced fractures
Amount of displacement dependent on favorable or unfavorable line of fracture
Line of fracture frequently through impacted third molar
Mobility of bone fragments as palpated with one hand on ramus and one on body
Fracture may be displaced medial or lateral
Ecchymosis of the floor of the mouth
Swelling of the floor of the mouth
Swelling of submandibular area of the face in the region of the angle
Probable anesthesia or paresthesia of the lip and chin in displaced fractures
Suspect body or subcondylar fractures on opposite side of the mandible
Infrequent location of fractures due to protection of masseter muscles
Often fractures in this location are extensions of subcondylar or angle fractures
Submasseteric space swelling
Malocclusion if fracture displaced; however, muscles tend to stabilize fracture
Suspect angle or body fractures on opposite side of the mandible
|Fractures may be|
- High: above the level of lateral pterygoid insertion
- Middle: immediately below the lateral pterygoid insertion
- Low: subcondylar, in the neck of condyle
Asymmetry of face chin deviated to the side of fracture
Anterior open bite due to premature posterior contact of teeth
Deviation of midline towards the side of the fracture on opening
Tenderness to palpation over temporomandibular-joint
Tenderness to palpation of anterior external auditory canal
Swelling or ecchymosis of skin in temporomandibular-joint region
Caused by severe blow directly to the side of the face
Isolated coronoid process fractures are rare
Often associated with fractures of the zygomatic arch
Rarely are displaced, as are stabilized by temporalis muscle
Pain and swelling over coronoid process
Treatment generally not necessary
Pain at the fracture site
Misalignment of the dental arch, if displaced
Arch may be narrowed due to telescoping of fragments
Mobility of bone fragments
Ecchymosis of the floor of the mouth, gingiva, and mucosa
Swelling of the floor of the mouth
Dentures will not fit if displaced, or tissue is swollen
Once diagnosed, fractures of the mandible are generally referred to an oral and maxillofacial surgeon for definitive treatment.
In many rural areas, patients may need to be transported over some distance to be seen by an oral and maxillofacial surgeon. Most patients who are seen in an outpatient dental office are sufficiently stable to be transported that distance. If trauma is severe enough that the patient was seen in an emergency room and the patient needs transportation, consideration should be given to the competency of the airway, swelling of the mouth or submandibular regions, and bleeding. Evacuation by medical helicopter or airplane should be considered.
Rarely the fractures need to be stabilized before transportation. If necessary, because of a delay in transportation or other reasons, some fractures may be temporarily reduced and temporarily stabilized by the dentist. This sometimes is also necessary to help with airway management, bleeding from a fracture site, or patient comfort. Under local anesthesia, displaced fractures can be bimanually reduced into anatomic position. A circumdental wire can be placed to stabilize fractures that occur between teeth. A 24-gauge wire is placed around 2 or 3 teeth on either side of the fracture and twisted tight to hold the fractured segments together.
The prime consideration in the definitive treatment by the oral and maxillofacial surgeon is establishing proper occlusion. This is done by placement of arch bars, generally from first molar to first molar, on the maxillary and mandibular arch. Any fractures through the dental arch are reduced and the teeth stabilized to the arch bar in normal alignment. Arch bars are stabilized by placing 24-gauze, circumdental wires around each tooth. After placement of the arch bars, any fractures that are not already reduced by the arch bar are bimanually reduced and the patient is brought into good intermaxillary occlusion. Three to five 26-gauze wires are placed between the maxillary and mandibular arch bars to immobilize the mandible, allowing for healing of the fractures. Intermaxillary fixation is sometimes accomplished using multiple rubber bands instead of wires. Placement of arch bars, bimanual reduction of fractures, and placement of intermaxillary fixation is called a closed reduction with intermaxillary fixation. Patients are generally in intermaxillary fixation for 6 to 8 weeks, depending on the location and severity of the fracture. Children are in intermaxillary fixation for shorter periods of time.
Some fractures cannot be reduced or
stabilized with closed reductions alone, requiring open reductions in addition. An open reduction
involves a surgical approach to the fracture site, reduction of the fracture, and stabilization of
the fracture with interosseous wires or bone plates. Some open reductions of the symphysis, body,
angle, and coronoid
process may be accomplished through an intraoral approach. Open reductions of the condyle require extraoral approaches, as do some fractures of the angle, body, or symphysis. Extensive fractures, comminuted fractures, and fractures with avulsions of portions of the mandible, such as those caused by gunshot wounds, require more extensive types of stabilization.
While the patient is in intermaxillary fixation, the patient will be on a completely liquid diet. Oral hygiene is difficult at best. Arch bars and intraoral lacerations make it difficult to brush the buccal and labial gingiva and it is not possible to brush the lingual gingiva. Plaque and bacteria cause gingival problems and foul breath. Sometimes the gingiva grows into or around the arch bars, especially in patients with poor oral hygiene.
Following the treatment of a mandible fracture, the patient should see a general dentist for continuing care. Hygiene and gingival condition should be assessed. Inflammation from arch bars normally resolves spontaneously with improved oral hygiene. Periodontal therapy may be needed in some cases. Teeth that were injured or that were adjacent to lines of fracture should be monitored for vitality.
|Figure 28: PA radiographic view of displaced left body fracture and displaced right angle fracture of mandible.|
Fractures of the midface include fractures of the bones of the maxilla, zygoma, zygomatic arch, and nose. Facial bone fractures are often seen in association with injuries to the teeth and mouth. While most dentists in general or specialty practice will not usually be treating these types of injuries, they will see patients with them. This chapter is provided so that all dentists who see dental injuries are familiar with and able to diagnose facial fractures in their patients.
The maxilla consists of four bones fused together, the right and left maxilla and the right and left palatine bones. From a functional standpoint it is considered one bone and is the largest part of the midface. Bones and processes of the maxilla contribute to the orbit, maxillary sinus, nasal cavity, and hard palate. Each maxillary bone has 4 processes that articulate with other bones. These are the frontal process, zygomatic process, and alveolar process. The maxillary teeth lie within the alveolar process. Superior to this is the maxillary sinus, the superior aspect of which is the floor of the orbit. Attached by strong buttresses of bone to the cranium, violent forces to the midface are absorbed by maxilla to protect the brain and spinal cord.
|Figure 29 : Displaced Le Fort fractures of the maxilla (type I, II, or III) will present with the posterior maxilla being displaced inferiorly, causing an anterior open bite.|
Fractures of the maxilla are relatively rare. They are seen much less often than fractures of the mandible. A significant impact to the midface is necessary in order to fracture the maxilla. Fractures of the maxilla are often caused by high-speed motor-vehicle accidents, falls from great heights, airplane crashes, and other high-impact forces. Any displacement of the maxilla is due to the impact itself. Unlike the mandible, muscle contraction has little effect on the displacement of fractures of the maxilla.
Because of the amount of trauma required to fracture the maxilla and the proximity to the skull, brain, orbits, nasal cavity, and maxillary sinuses, fractures of the maxilla are serious injuries. Major arteries, veins, and nerves are in the region.
Three types of fractures of the maxilla are generally described: Le Fort I, Le Fort II, and Le Fort III fractures. They are based on the fact that the maxilla tends to fracture along suture lines with adjacent bones. In practice, however, fractures are often comminuted and bones are "smashed" instead of following suture lines.
A Le Fort I fracture, also called a transverse maxillary fracture or a Guerin fracture, is a horizontal fracture that occurs through the walls of the maxilla at a level above the teeth. Note that some authors use the term transverse fracture to indicate a Le Fort III craniofacial disjunction type of fracture. The terms Le Fort I, Le Fort II, and Le Fort III are most often used to avoid any miscommunication.
Le Fort I fractures are similar in location to Le Fort I osteotomies used to correct malocclusion. The segment that is displaced from the base of the skull includes the alveolar process, teeth, palate, portions of the walls of the maxillary sinus and vomer bone, and lower regions of the pterygoid process of the sphenoid bone. This creates a "floating maxilla" that is attached only by soft tissue.
|Figure 30 : PA radiograph of a Le Fort I fracture of the maxilla with additional fracture through the palatal suture. Maxillary sinuses and nasal cavity are visible.||Figure 31 : PA tomogram of Le Fort II fracture of the maxilla, showing fractures of both infraorbital rims and the nasofrontal suture (arrows).|
Diagnosis of a maxillary fracture is usually straightforward. There is often external trauma, such as bruising, abrasions, lacerations, or swelling, of the lips or midface. Teeth may have fractures or be displaced from their alveolar sockets. If the fracture is partial or not displaced, the occlusion may be normal and the fracture minimally mobile. If the posterior maxilla has been impacted, the maxilla may not be mobile, but an anterior open bite will be present. If the maxilla is displaced, such as in a "floating maxilla," there will be an anterior open bite and the maxilla will be grossly mobile. Care must be taken to distinguish between an alveolar fracture of the maxilla and a total Le Fort I fracture.
With the latter, moving the anterior alveolus will move the entire palate and maxilla. With an alveolar fracture, only the anterior alveolar segment will move. Bleeding from the nose may be present. Occasionally, the maxilla will also fracture along the palatal suture. In such cases, the right and left maxillae may move independent of each other and there may be ecchymosis or lacerations of the palatal tissue.
Clinical examination is the most reliable method to diagnose a Le Fort I fracture of the maxilla. It is difficult to see fracture lines with radiographic examination, especially with a panoramic radiograph. A PA cephalometric, lateral skull, or Water's view may show fractures of the lateral walls of the maxilla, fractures of the walls of the nasal cavity, and blood in the maxillary sinus. A lateral cephalometric or lateral skull film may show posterior displacement of the maxilla, or an open bite. All of these radiographic findings should also be apparent on clinical examination.
Patients with Le Fort I fractures that are diagnosed in the dental office should be referred to a oral and maxillofacial surgeon for definitive treatment. Most often, treatment involves placement of arch bars, reduction of the fracture, and stabilization by bringing the maxillary fracture in occlusion with a stable mandible and wiring in place with intermaxillary fixation. Open reductions with interosseous wires or bone plates may also be used at times.
Le Fort II fractures of the maxilla, also known as pyramidal fractures, are caused by forceful impact to the upper maxillary region. This produces fractures of the frontal process of the maxilla and nasal bones. It is unlikely a patient with a Le Fort II fracture will present to the dental office instead of a hospital-emergency room.
Fractures extend from the nasofrontal suture laterally and inferiorly along the lacrimal bones, infraorbital rim, near or through the zygomaticomaxillary suture, the posterior lateral wall of the maxilla, and the pterygoid plates. From the nasal bones, it extends posteriorly through the perpendicular plate of the ethmoid bone and the medial walls of the maxillary sinus. Because of the general shape of this extensive fracture, it has also been called a pyramidal fracture. Le Fort II fractures may be associated with concomitant injuries, including head or brain injuries, basal-skull fractures, neck injuries, orbital injuries, and cerebrospinal rhinorrhea.
Clinical examination of a patient with a Le Fort II fracture shows a patient who is swollen throughout the entire middle face, including the nose and lips. The eyes may be swollen shut. Ecchymosis may be present in the eyelids and face. The white sclera of the eyes may be bright red due to subconjunctival hemorrhage. Cerebrospinal fluid may be draining through the nose, presenting as a clear fluid, as a result of a fracture of the cribriform plate of the ethmoid bone forming the base of the skull. Palpation of the anterior-maxillary alveolus will show mobility of the entire maxilla. Crepitus or mobility may be palpated over the infraorbital rims and nasofrontal suture.
Often, the bones involved in Le Fort II injuries are comminuted or crushed due to the severity of the injury. There may be significant damage to the lacrimal, ethmoid, and nasal bones, causing widening of the interorbital space or damage to the nasolacrimal duct.
Treatment involves stabilization of the fractures to restore the occlusion and stop cerebrospinal fluid drainage. Application of arch bars, and restoration of intermaxillary occlusion, followed by intermaxillary fixation, are necessary. If there is inferior displacement of the fracture that is reduced by the upward pull of the elevator muscles, internal fixation is necessary. The maxilla is suspended from wires passed around the zygomatic arch or by direct interosseous wiring of the fractures of the infraorbital rims.
Also known as craniofacial disjunction (or by some, transverse fractures), a Le Fort III fracture is a severe injury where the facial bones are literally torn from the base of the skull. It is unlikely a patient with a Le Fort III fracture will present to the dental office instead of a hospital-emergency room.
Le Fort III fractures are high, transverse fractures that usually occur along suture lines. Fractures extend through the zygomaticofrontal, maxillofrontal, and nasofrontal sutures, and then extend through the orbits, ethmoid bone, and sphenoid bone. Often such fractures are a combination of Le Fort II and Le Fort III fractures, extending along the zygomaticomaxillary suture. Orbital-blowout fractures of the floor of the orbit and multiple other facial fractures may be present, given the severe nature of the force required to cause a Le Fort III fracture. Neurological and neck injuries are also common concomitant injuries.
Clinical examination will show a patient that has the same general swollen and bruised appearance as a patient with a Le Fort II fracture. The midface may appear to be dished in. Cerebrospinal rhinorrhea may be present.
Treatment involves arch-bar application and intermaxillary fixation along with surgical repair of the multiple fractures. Craniofacial stabilization is sometimes necessary too, for stability and to restore proper facial height.
Fractures of the zygoma, also known as the malar bone, are caused due to a blow to the "cheekbone." Zygoma fractures are also known as malar-complex fractures. Despite being buttressed in strong bone between the cranium and maxilla, the prominence of the zygoma in the face makes it susceptible to injury. Common causes of fractures include motor-vehicle accidents and fights.
In zygomatic-complex fractures the zygoma bone itself is rarely fractured. Instead, fractures occur at its attachment by sutures to other bones. The fracture involves the zygomaticotemporal suture, the zygomaticomaxillary suture, and the zygomaticofrontal suture, and extends through the infraorbital rim and floor of the orbit. The zygoma bone itself is often displaced into the maxillary sinus. Periorbital fat or extraocular muscles may herniate through the orbital floor into the sinus.
Clinical examination may show a patient with a flattened face and depressed zygoma. Looking down from the top of the skull is a good way to compare the symmetry of the zygomatic complex and the zygomatic arch. The lateral-palpebral ligament may be displaced inferiorly with the lateral orbit, causing retraction of the lower lid, diplopia, and downward displacement of the eye. Ecchymosis and edema of the lower lid may be present along with subconjunctival hemorrhage. Bleeding into the sinus from torn tissues and bone may cause unilateral epistaxis. When the temporal process of the zygoma is depressed into the temporalis muscle, severe trismus and pain on opening the mouth may occur.
Radiographic examination will show the fracture of the infraorbital rim, the zygomaticoorbital suture, and a blood level in the maxillary sinus. Sometimes, a blowout fracture of the orbital floor is also present.
Treatment of a zygomatic-complex fracture is surgical. Depending on the position and amount of displacement, various surgical techniques are employed. A common procedure is to make incisions above the lateral brow and below the lower eyelid. Dissection is then made to the fractures of the zygomaticofrontal suture and infraorbital rim. The fracture is reduced and direct interosseous wires placed in the orbital rim to stabilize the zygoma.
|Figure 32 : View from below showing flattening of right cheekbone, as compared to left side, from depressed right zygomatic (malar) complex fracture. Also note ecchymosis around eye and subconjuctival hemorrhage.|
Fractures of the zygomatic arch are caused by direct impacts to the arch. The zygomatic arch is composed of the zygomatic process of the temporal bone and the temporal process of the zygomatic bone. The temporalis muscle passes through the arch and the masseter muscle is attached laterally.
Fractures of the arch depress the arch inward, fracturing it in three places: along the zygomatic process of the temporal bone, the temporal process of the zygomatic bone, and the zygomaticotemporal suture. The temporalis fascia prevents downward displacement and the masseter muscle prevents superior displacement. Zygomatic-arch fractures do not involve the orbit or maxillary sinus.
Clinical features of zygomatic arch fractures include a depression of the arch to palpation, pain on opening the mouth, and trismus.
Treatment is surgical via an intraoral or extraoral approach. When the fracture is reduced it will often "snap" into position and remain in place without fixation.
Fractures of the nasal bones are common isolated injuries due to the prominence of the nose and may also occur in accidents in which the face is thrown forward injuring teeth. Different types of fractures of the nasal complex are caused by impacts from the front, side, or base of the nose.
Any part of the nasal complex may be fractured. One or both nasal bones may be fractured. They may be detached from the maxilla, the nasal septum, or the frontal bone. Fractures of the internal septal bones, the perpendicular plate of the ethmoid or the vomer bone, may occur. Septal cartilages may be torn, fractured, or displaced. The exact diagnosis of the type of nasal fracture can be difficult, but it is not difficult to establish that a nasal fracture exists and a referral to a surgeon is indicated.
Clinical examination is often more useful than radiographic examination. Crepitus or bone movement on palpation over the nasal bones may be present along with pain on palpation. Intranasal structures including the septum may be fractured or deviated. Swelling and ecchymosis of the eyelids and nose may be present, as may be subconjunctival hemorrhage. The internal-nasal cavity may be obstructed with blood clots, mucosal swelling over the turbinate bones, and edema.
Treatment of nasal fractures is by closed or open reduction, depending on the specific injury.
At no time in dental school was I taught what to do for dental injuries that occur outside the office or hospital. While backpacking one day, I was eating lunch with friends on top of a 10,000-foot high mountain peak when all of a sudden one person screamed out in pain. He had fractured the buccal cusps of a molar on a peanut and had a pulp exposure. I opened our first-aid kit and, of course, found that there was nothing in it that I could use to help him. Fortunately, some softened wax from a survival candle helped cover the exposure until we could get him down the mountain.
Dental injuries and problems in the field are not that uncommon. Hunters frequently fracture teeth by biting down on steel shot found while eating ducks or pheasants they have shot. Restorations can fracture or become loose when biting down wrong on any number of things, such as candy, nuts, or ice cubes. Tripping or falling over rocks and logs can lead to fractures, displacement, or avulsion of teeth, to fractures of the mandible or facial bones, or to lacerations. Often the injured person is in remote areas hours or days away from dental care.
Many people know medical first aid, but few know dental first aid. As a dentist, you may be called upon to treat such injuries when they occur on a trip in which you are participating. Also, with the increasing use of cellular and satellite phones, you may start receiving phone calls from injured patients in remote-wilderness areas asking you what they should do to treat a dental emergency until they can see you.
If you have patients in your practice that hunt, fish, backpack, motorcycle, or participate in sports activities in areas not readily accessible, you may want to suggest to them that they include a dental first-aid kit as part of their first-aid kit. Also, those patients who take urban-emergency preparedness seriously would also want to have a dental first-aid kit. In case of large disasters or widespread power outages, dental services will be limited for a time.
A few items needed in dental emergencies in the field can easily be added to a medical first-aid kit. At a minimum, these would include the following, all of which are available in a dental office:
Cavit or Tempanol
Cotton pliers or other small tweezers
Small flat spatula-type instrument
Latex or vinyl gloves
A dentist may want to include other materials in the personal kit, depending on the remoteness of the location and access to local-dental care. These might include analgesics, antibiotics, a sterile-scalpel blade, sterile surgical drain, or fast-set acrylic for temporary denture repair.
Patients as a matter of course will not have access to dental materials and instruments. There are numerous commercially available alternatives, however. The following are some examples of materials commonly available without prescription at most pharmacies, drug stores, and markets. Other brands may be substituted if appropriate.
Commonly available commercial toothache medications include Red Cross Toothache Medicine containing 85% eugenol, Dent's Toothache Drops containing benzocaine and eugenol, and Orajel containing benzocaine. Some products include small-dental tweezers and cotton pellets.
Tempanol or Cavit are available for use as temporary restorative material. An alternative, if caught without these materials, is to use soft-dental (orthodontic) wax or softened wax from a candle. If a candle is used, wax is melted and let cool until it is pliable.
Adventure Medical Kits sells a dental first-aid kit called Dental Medic. Available at outdoor recreation stores, it is a pocket-sized plastic container that contains soft-dental wax, dental floss, a tube of SuperDent/Cavit, Orasol Gel, toothpicks, cotton pellets, cotton rolls, a tea bag, and written instructions for dental first aid. It is an easy way for patients to have everything they need.
While proper dental materials and techniques are preferable, there are times when materials and treatment need to be improvised in the field. Although this course is about traumatic dental injuries, field treatment of other common dental emergencies is also included in this section.
Proper care of teeth is important during a backcountry trip or survival situation, yet it is one of the first things people forget to do when they are in the wilderness. If a toothbrush is forgotten or lost, the end of a thin-green twig from a nonpoisonous tree or bush can be used as a brush to remove plaque. It can be chewed until it is soft and fibery and then the end used as a brush to clean teeth and gingival.
Game meat, such as deer and moose, can be stringy and become lodged in interproximal spaces. Flossing can be important to prevent localized gingival infections.
Pain from acute pulpitis due to caries or a fracture can incapacitate a person in a wilderness or field situation. Sometimes, an abscess in a tooth with a large carious lesion will drain through an opening in the cavity in the crown of the tooth. After eating, food may become lodged into the cavity preventing drainage of the abscess. Pressure in the pulp chamber will increase causing pain. This food can be removed with a toothpick, toothbrush, dental instrument, or small knife to allow for spontaneous drainage.
To treat acute pulpitis in the field, a cotton pellet (or a small piece of gauze or other material) is saturated in topical anesthetic, such as eugenol or benzocaine, and placed into the carious lesion or fracture. This can be placed with cotton pliers, small tweezers such as those used for tick removal, or an improvised tool such as a toothpick. This should give rapid relief. A temporary filling material may then be placed to keep the cotton pellet in place.
If available, nonsteroidal antiinflammatory drugs or narcotic analgesics, such as Vicodin, and antibiotics can be administered.
Abscesses may require incision and drainage in the field to relieve pain and spread of infection. The technique used is the same as one that would be performed in a dental office; however, proper instruments and materials may not be available.
It is unlikely that injectable local anesthesia would be available in the field. Topical-anesthetic liquids may be available in a medical first-aid kit. Topical anesthesia may also be achieved by applying ice or snow over the tissue immediately prior to incision.
Preferably, a sterile scalpel blade found in a medical or dental first-aid kit should be used to make the incision. If one is not available, other sharp instruments can be used, including a sharp knife, needle, or fishhook with the barb removed. They should be disinfected by heating over a match or other flame. A T-shaped drain can be placed to keep the incision open and draining. If sterile-drain material is not available, a drain may be improvised from a piece of latex or vinyl glove, or gauze material. Antibiotics should be administered if available, provided the patient is not allergic.
While an incision and drainage procedure may not be comfortable for the patient in the field, it can be done quickly and will relieve the pain almost immediately and help prevent the abscess from spreading.
Lost restorations can be filled with temporary materials, such as Cavit or Tempanol, or improvised materials, such as wax from a candle described above, to prevent impaction of food or sensitivity to temperature.
Prosthetic crowns that become dislodged do not need to be temporarily replaced unless the tooth is sensitive to temperature. If they need to be reseated, a thin layer of temporary filling material, denture adhesive, or even a thick slurry of water and flour can be used as temporary cement.
Displaced teeth can often be manipulated into place and held in position by biting on gauze. Avulsed teeth should be cleaned with water and reimplanted as described in the chapter on injuries to permanent teeth. Again, they can be held in place by biting on gauze. Typically, there will be nothing available to stabilize the teeth in the usual fashion. If dental care is not available in a reasonable time and periodontal packing material is present in the first-aid kit, it can be used to stabilize the teeth.
Fractures of the nose and mandible are possible in back country injuries from falls, horseback accidents, and vehicle collisions, among other things. They are generally not life threatening and require no immediate care other than stopping any bleeding with pressure and evacuating the injured person to medical care. If evacuation of the injured person is delayed, a bandage (elastic bandage, gauze bandage, etc.) may be placed under the mandible and around the top of the head to support the mandible in a closed position. Nasal fractures require no treatment in the field except stopping any bleeding.
Midface fractures are generally from high-speed impact and are rare in the field unless vehicles are being driven. They may also occur with falls from high elevations. Again, they do not require emergency stabilization before evacuation of the patient to medical care.
|Figure 34 : A complete dental first- aid kit should contain eugenol, Cavit or Tempanol, cotton pellets, dental floss, soft wax, small tweezers, and a spatula-type instrument.||Figure 33 : Many types of temporary filling materials are available to patients to carry in their first-aid kits. Tempanol is one brand that contains putty-like temporary material and an applicator stick.|