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3-1. GENERAL

Fractures and dislocation of the jaw occur frequently among members of the military population, particularly in combat. Immediate treatment involves lifesaving techniques to maintain respiration, control hemorrhage and shock, and observation for possible brain damage. Immediate treatment should also include immobilization of the head and neck to prevent damage to the spinal cord until the possibility of injury to the cervical spine has been ruled out at a definitive care facility. Among the more common traumatic facial injuries are fractures of the mandible and maxilla. Displaced bone segments from fractures of the maxilla and bilateral subcondylar or parasymphysis fracture of the mandible may result in airway problems. These fractures are often associated with soft tissue injury or loss, bone loss, and comminuted or impacted fragments of bone. Jaw fractures and associated injuries should be referred to the dental officer (usually an oral surgeon) for treatment. A diagnosis is usually established following a thorough examination that includes visual inspection, palpation, and radiographs.

3-2. COMMON SIGNS AND SYMPTOMS

Most patients with jaw fractures have a history of trauma and complain of pain. In addition, many patients have abnormal mobility of the fractured jaw and trismus (muscle spasm). Some common signs and symptoms of mandibular fractures include: malocclusion, laceration over the fracture site, ecchymosis (bleeding into the skin or mucosa) in the floor of the mouth, step defect, paresthesia (numbness or abnormal sensation), lack of condylar movement on opening, lateral deviation on opening, and the inability to open the mouth. Fractures of the maxilla and other bones of the mid-face have the following common signs and symptoms: distortion of facial symmetry, open bite due to displacement of the maxilla, ecchymosis, and paresthesia.

3-3. CLASSIFICATION OF FRACTURES

Fractures may be classified by their severity and tissue involvement. Figure 3-1 has examples of some types of fractures.

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Figure 3-1. Types of mandibular factures.

Simple Fracture. A simple fracture is a break in the bone that does not produce an open wound in the skin. A simple fracture can be complete (complete severance of the bone) or incomplete. Tissue adjacent to the fracture may or may not suffer considerable injury.

NOTE: A greenstick fracture is one in which one side of the bone is broken and the other side is bent.

Compound Fracture. A compound fracture is a break in the bone with an external wound extending to the bone. Communication from the bone to the skin or other covering surface is an invitation for contamination.

Comminuted Fracture. A comminuted fracture is one in which the bone is splintered into three or more fragments or is crushed.

NOTE: A compound-comminuted fracture is one with both a splintering of the bone and a break in the bone with an opening to the covering surface.

Depressed Fracture. A depressed fracture is a break in which the fractured part is driven below the normal level of the bone, as in a skull fracture.

Impacted Fracture. An impacted fracture is a break in which the hard cortical bone of one fragment is driven into the softer cancellous bone of another fragment.

Pathologic (Spontaneous) Fracture. A pathologic fracture is a break without external violence at an area of the bone that has been weakened by a local disease.

Multiple Fracture. A multiple fracture is a break in which two or more fractures occur in the same or different bones.

Favorable Fracture. A favorable fracture is when the line of the fracture occurs in a direction that does not allow the pull of the muscles on the segments to displace the segments.

Unfavorable Fracture. An unfavorable fracture is a fracture with displacement or separation of the fractured segments due to muscle pull on the segments.

3-4. FRACTURES OF FACIAL BONES

Fractures of the Maxilla. Fractures of the maxilla commonly occur as horizontal fractures through the floor of the nose, horizontal fractures of the premaxillary area, tuberosity fractures, alveolar process fractures, and nasal process fractures. (The nasal bone is the most common facial bone fracture.) See figure 3-2.

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Figure 3-2. Fractures of the maxilla.

Fractures of the Mandible. The mandible is the second most commonly fractured facial bone. Fractures of the mandible commonly occur in the body of the mandible, the neck of the condyle, and the angle of the mandible. See figure 3-3.

Fractures of the Zygomatic Bone. Fractures of the zygomatic bone include fractures involving the zygomatic arch (cheekbone) as well as the temporal, frontal, and maxillary bones.

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Figure 3-3. Fractures of the mandible.

3-5. TREATMENT OF FRACTURES

Treatment of fractures requires restoration of the parts to their normal positions (reduction of a fracture) and immobilization (fixation) of the parts for about 6 to 8 weeks until a union between the bony parts takes place. Reduction of the fracture may be either closed or opened. In a closed reduction, the bone segments are manipulated back into position without surgically exposing the bone. Usually arch bars and wires are used for fixation. In an opened reduction, the fractured bone segments are surgically exposed, which allows the fracture to be reduced exactly because of unobstructed, direct vision. In opened reductions, fixation generally is accomplished by drilling holes on either side of the fracture and using wire or metal plates to hold the segments in close approximation. Careful postoperative care is needed. Patient instruction in proper diet is essential because often the teeth are immobilized in the closed position, called intermaxillary fixation (the jaws being wired together). A dental liquid or soft diet is used because it is a high protein and high carbohydrate diet that provides the nutrients necessary for the healing of fractured bones.

3-6. DISLOCATION OF THE JAW

In a dislocation of the mandible, the head of the condyle is displaced from its normal relationship with the glenoid fossa. The condylar head slips down and out of the glenoid fossa and in front of the articular tubercle or eminence. The patient is unable to close his mouth, and often there is pain, discomfort, and swelling. Dislocation of the jaws may be caused by a blow, yawning, laughing excessively, or otherwise opening the mouth too wide. In all cases, the dental officer or some other trained person should be summoned immediately, for it is essential to restore the joint to its normal position as rapidly as possible. This is done by placing the thumbs in the posterior sulcus of the mandible in the region of the molar teeth and pressing downward and backward to slip the condyle under the articular tubercle. Since the jaw is likely to slip back into place quickly, it is essential to prevent the anterior teeth from being traumatically fractured.

David L. Heiserman, Editor

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Revised: June 06, 2015