Blunt trauma, mandibular pain, and malocclusion are typically seen in patients with mandibular fractures. A step-off in the dental line or ecchymosis or hematoma to the floor of the mouth is often present. Mandibular fractures may be open to the oral cavity, as manifested by gum lacerations. Dental trauma is frequently seen. Other clinical features include inferior alveolar or mental nerve paresthesia, loose or missing teeth, dysphagia, trismus, or ecchymosis of the floor of the mouth (considered pathognomonic). Multiple mandibular fractures are present in more than 50% of cases because of the ringlike structure of the mandible. Mandibular fractures are often classified as “favorable” or “unfavorable.” Fractures displaced by masseter muscle contraction are unfavorable and inevitably require fixation, whereas fractures that are not displaced by masseter contraction are favorable and, in most cases, will not require fixation. Injuries creating unstable mandibular fractures may create airway obstruction because the support for the tongue is lost. Mandibular fractures are also classified based on the anatomic location of the fracture. Dislocation of the mandibular condyles may also result from blunt trauma and will always have associated malocclusion, typified by an inability to close the mouth.
Open Mandibular Fracture. An open fracture is suggested by the misaligned teeth and gingival disruption. (Photo contributor: Lawrence B. Stack, MD.)
Management and Disposition
A dental panoramic film is the best diagnostic image for evaluating mandibular trauma. If only plain films are available, obtain anteroposterior, bilateral oblique, and Towne views to evaluate the condyles. Treat nondisplaced fractures with analgesics, soft diet, and referral to oral surgery in 1 to 2 days. Displaced fractures, open fractures, and fractures with associated dental trauma need urgent consult. Treat all mandibular fractures with antibiotics effective against anaerobic oral flora (clindamycin, amoxicillin/clavulanate) and give tetanus prophylaxis if needed. The Barton bandage has been suggested to immobilize the jaw in the ED.
The most sensitive sign of a mandibular fracture is malocclusion. The jaw will deviate toward the side of a unilateral condylar fracture on maximal opening of the mouth.
A nonfractured mandible should be able to hold a tongue blade between the molars tightly enough to break it off. There should be no pain in attempting to rotate the tongue blade between the molars.
Bilateral parasymphyseal fractures may cause acute airway obstruction in the supine patient. This is relieved by pulling the subluxed mandible and soft tissue forward and, in patients in whom the cervical spine has been cleared, by elevating the patient to a sitting position.
Sublingual Hemorrhage. Hemorrhage or ecchymosis in the sublingual area is pathognomonic for mandibular fracture. (Photo contributor: Lawrence B. Stack, MD.)