Imaging Studies
Radiographs
X-ray projections typically have been used to detect a mandibular fracture but are limited to anteroposterior (AP), lateral, and oblique views in an unstable trauma patient. These views are inadequate to detail the level of fracture displacement, and they show poor detail in the condylar region. [23]
The best plain film for assessment of the mandible is a panoramic view (ie, Panorex), which shows the mandible in its entirety in a single view. The panoramic view is not always available, as it requires a special radiographic machine. If the panoramic view is not available, or if the patient is unable to sit for the film, obtain routine mandible films.
Routine views include bilateral lateral oblique projections (to look at the angle, the body, and, to a lesser extent, the symphysis) and Townes view (to look at the condyles).
The submental view can be helpful in evaluating the symphysis.
Obtain chest films for patients with unaccounted for missing teeth to rule out aspiration.
Cervical spine radiographs may be indicated for patients with severe facial injuries, or for patients with a consistent mechanism and neck pain. [6]
CT, US, and MRI
For selected patients with nondiagnostic radiographs in whom mandibular fracture is strongly suspected, computed tomography (CT) may be necessary to diagnose condylar fracture. CT scan of the brain should be considered to rule out intracranial injury. [3, 4, 5]
CT is the imaging modality of choice when a traumatic mandibular injury is assessed. Multidetector-row CT reduces motion blur and therefore produces accurate coronal and sagittal reconstructions with 100% sensitivity in detecting a fracture. Furthermore, reconstructive 3-dimensional CT images gained from planar views allow better understanding of the spatial relationship of the fracture to other anatomic landmarks, ensuring better appreciation of the severity and classification of a mandibular fracture and enhancing operative planning. [23]
Multidetector-row CT is used to determine the most appropriate treatment, management, fixation method, and surgical approach; to assess the adequacy of reduction; and to evaluate potential complications in the postoperative period. [31]
Ultrasonography (US) is another useful modality for detecting a mandibular fracture when the patient is too unstable to be transferred to a CT scanner. Sensitivity, however, is less in comparison to a CT series of images, and limited detail on the fracture pattern is revealed. [23]
Magnetic resonance imaging (MRI) can be used to assess soft tissue injury of the temporomandibular joint, such as hematoma, as well as complications of trauma. [11] However, this is unlikely to be a matter of priority when a trauma patient is first assessed. [23]
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Anatomy of the mandible.
