1.
The Dental-Trauma Patient
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 neededExamination of the Dental-Trauma Patient
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.
History
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:
General
/ 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?
Medical
/ 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?
Dental
/ 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?
Clinical Examination
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.
Extraoral Examination
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.
Oral Examination
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.
With 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.
Radiographic Examination
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.
2.
Injuries to Permanent Teeth
Concussion and Subluxation
General Considerations
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.Treatment
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.
Crown Fractures
General Considerations
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.
Enamel Fractures
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.
Enamel and Dentin Fractures
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 Into the Pulp
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 completerootformation 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.