Bilateral condylar fractures may cause the above signs and symptoms, but on both sides. Malocclusion and restricted jaw movement are usually more severe. Bilateral body or parasymphysis fractures are sometimes termed "flail mandible", and can cause involuntary posterior movement of the tongue with subsequent obstruction of the upper airway. Displacement of the condyle through the roof of the glenoid fossa and into the middle cranial fossa is rare. Other rare complications of mandibular trauma include internal carotid artery injury, and obliteration of the ear canal due to posterior condylar dislocation. Bilateral condylar fractures combined with a symphyseal fracture is sometimes termed a guardsmans fracture. The name comes from this injury occurring in soldiers who faint on parade grounds and strike the floor with their chin. Diagnosis
Plain film radiography
Traditionally, plain films of the mandible would be exposed but had lower sensitivity and specificity owing to overlap of structures. Views included AP (for parasymphsis), lateral oblique (body, ramus, angle, coronoid process) and Townes (condyle) views. Condylar fractures can be especially difficult to identify, depending on the direction of condylar displacement or dislocation so multiple views of it are usually examined with two views at perpendicular angles. Panoramic radiography
Panoramic radiographs are tomograms where the mandible is in the focal trough and show a flat image of the mandible. Because the curve of the mandible appears in a 2-dimensional image, fractures are easier to spot leading to an accuracy similar to CT except in the condyle region.
The mandible is usually divided into the following zones for the purpose of describing the location of a fracture (see diagram): condylar, coronoid process, ramus, angle of mandible, body (molar and premolar areas), parasymphysis and symphysis. Alveolar
This type of fracture involves the alveolus, also termed the alveolar process of the mandible. Condylar
Condylar fractures are classified by location compared to the capsule of ligaments that hold the temporomandibular joint (intracapsular or extracapsular), dislocation (whether or not the condylar head has come out of the socket (glenoid fossa) as the muscles (lateral pterygoid) tend to pull the condyle anterior and medial) and neck of the condyle fractures. E.g. extracapsular, non-displaced, neck fracture. Pediatric condylar fractures have special protocols for management. Coronoid
Because the coronoid process of the mandible lies deep to many structures, including the zygomatic complex (ZMC), it is rare to be broken in isolation. It usually occurs with other mandibular fractures or with fracture of the zygomatic complex or arch. Isolated fractures of the coronoid process should be viewed with suspicion and fracture of the ZMC should be ruled out. Ramus
Ramus fractures are said to involve a region inferiorly bounded by an oblique line extending from the lower third molar (wisdom tooth) region to the posteroinferior attachment of the masseter muscle, and which could not be better classified as either condylar or coronoid fractures. Angle
The angle of the mandible refers to the angle created by the arrangement of the body of the mandible and the ramus.