Clinical examination

• Advanced trauma life support protocol
• Note facial lacerations, swellings, and hematomas. A common site for a laceration is under the chin, and this should alert the clinician to the possibility of an associated subcondylar or symphysis fracture.
• From behind the supine or seated patient, bimanually palpate the inferior border of the mandible from the symphysis to the angle on each side. Note areas of swelling, step deformity, or tenderness.
• Note areas of paresthesia, dysesthesia, or anesthesia along the distribution of the inferior alveolar nerve. Numbness in this region is almost pathognomonic of a fracture distal to the mandibular foramen.
• Standing in front of the patient, palpate the movement of the condyle through the external auditory meatus. Pain elicited through palpation of the preauricular region should alert the clinician to a possible condylar fracture.
• Observe any deviation on opening of the mouth. Classically, deviation on opening is toward the side of the mandibular condyle fracture. Note any limited opening and trismus that may be a result of reflex muscle spasm, temporomandibular effusion, or mechanical obstruction to the coronoid process resulting from depression of the zygomatic bone or arch.
• Changes in occlusion are highly suggestive of a mandibular fracture. A change in occlusion may be due to a displaced fracture, fractured teeth and alveolus, or injury to the temporomandibular joint.
• Look for intraoral mucosal or gingival tears. Floor of the mouth ecchymosis may indicate a mandibular body or symphyseal fracture.
• If a fracture site along the mandible is suggested, grasp the mandible on each side of the suspected site and gently manipulate it to assess mobility.

The indications for closed versus open reduction have changed dramatically over the last century. The ability to treat fractures with open reduction and rigid internal fixation (ORIF) has dramatically revolutionized the approach to mandibular fractures.

Traditionally, closed reduction (CR) and ORIF with wire osteosynthesis have required an average of 6 weeks of immobilization mandibular fracture (IMF) for satisfactory healing. Difficulties associated with this extended period of immobilization include airway problems, poor nutrition, weight loss, poor hygiene, phonation difficulties, insomnia, social inconvenience, patient discomfort, work loss, and difficulty recovering normal range of jaw function.

In contrast, rigid and semirigid fixation of mandible fractures allow early mobilization and restoration of jaw function, airway control, improved nutritional status, improved speech, better oral hygiene, patient comfort, and an earlier return to the workplace.

The technique of rigid internal fixation was developed and popularized by AO/ASIF (Arbeitsgemeinshcaft fur Osteosynthesefragen/Association for the Study of Internal Fixation) in Europe in the 1970s. The basic principles of the AO, outlined by Spiessl, call for primary bone healing under conditions of absolute stability. Rigid internal fixation must neutralize all forces - tension, compression, torsion, and shearing - developed during functional loading of the mandible to allow for immediate function. This is accomplished by interfragmentary compression plates. Use an inferior border plate to counter compression forces and a superior border plate or arch bars to counter traction or tension forces at the superior border.

AO reconstruction plates also impacted the management of comminuted and infected mandibular fractures. Ellis reported a 7.5% infection rate in treatment of mandibular angle fractures with and AO reconstruction plate without IMF.

During the same time that Spiessl was expounding the AO doctrine, Champy et al in France was developing the concept of adaptive osteosynthesis. Champy advocated transoral placement of small, thin, malleable stainless steel miniplates with monocortical screws along an ideal osteosynthesis line of the mandible. Champy believed that compression plates were unnecessary due to masticatory forces that produce a natural strain of compression along the inferior border.

These two changes of AO rigid internal fixation and the Champy method of monocortical miniplates revolutionized the treatment approach to mandibular fractures. Many fractures previously treated with closed reduction or open reduction with wire osteosynthesis are now commonly treated with open reduction with plate and screw fixation. An example of this evolution is the treatment of comminuted mandibular fractures. These were thought to be treated best by closed reduction to minimize stripping of the periosteum of small bone fragments. Although this treatment modality is still used, rigid fixation now enables the clinician to avoid closed reduction with the use of reconstruction plates and good soft tissue coverage.