Mandibular Fracture

David B. Hom

History

A 27-year-old man, involved in an altercation, was kicked to the jaw and anterior neck 2 hours previously. He did not lose consciousness. Since then, he complains of malocclusion and difficulty opening his mouth. He notes some neck discomfort and hoarseness but has full range of motion of his neck. On physical examination he has shifting of his jaw to the left and premature contact on his left posterior second molars (teeth #15 and #18). He also has numbness of his right anterior chin. The tympanic membrane is intact with no hemotympanum.

Differential Diagnosis—Key Points

By history and examination, several clinical entities must be considered with this presentation:

1. All patients with head and neck trauma warrant cervical spine evaluation to rule out cervical spine injury, which include cervical spine radiographs and clinical examination. Even in the emergent setting when the clinical situation dictates against complete cervical spine radiographs, the neck must be immobilized and protected from any out-of-axis movements until appropriate cervical injury is ruled out. In some instances low cervical spine injury can be missed despite performance of full cervical radiographic series because of the difficulty of radiographically imaging this area in an injured patient.

2. Laryngotracheal injury must be ruled out in patients who have cervical trauma with symptoms of tenderness at the laryngeal tracheal region, hoarseness, or dyspnea, Serious types of laryngotracheal injuries are fractures of the laryngeal or cricoid cartilages and laryngotracheal separation. Laryngeal fractures may present with anterior neck ecchymosis, subcutaneous crepitance (from free air dissecting out into the soft tissue planes), or crepitance with palpation of the laryngeal fracture. Fiberoptic flexible scope examinations may show edema, ecchymosis, or distortion of the internal anatomy. Hoarseness may be present. In laryngotracheal separation, the trachea is torn away from the larynx. In this instance, the patient may initially still have a good airway, but the airway will progressively decrease, requiring a tracheotomy.

3. Significant blunt cervical trauma can result in vascular involvement. This injury would include intimal disruptions of the carotid.

5. If the patient has missing or fractured teeth, suspicion for aspiration of a fractured tooth should be considered and a chest radiograph performed.

6. Most mandible fractures occur in pairs. When two fractures occur on the mandible, the mandibular bone is frequently drawn posteriorly by the attached lingual musculature. In addition, the suprahyoid musculature loses its stabilizing insertion points, which could result in a narrowed airway and inability to clear secretions. In this instance, airway obstruction can occur, which should be treated as an immediate priority.

Test Interpretation