Radiology, Vol 180, 463-466, Copyright © 1991 by Radiological Society of North America
Air in the temporomandibular joint fossa: CT sign of temporal bone fracture
BW Betz and MD Wiener
Department of Radiology, Duke University Medical Center, Durham, NC 27710.
Temporal bone fractures can be difficult to detect clinically and
radiographically. Air is sometimes present in the glenoid fossa of the
temporomandibular joint (TMJ) at computed tomography (CT) of acute basilar
skull fractures. This study evaluated TMJ fossa air as a sign of temporal
bone fracture. Initial CT scans of the head in 114 patients with a
diagnosis of basilar skull fracture at discharge were retrospectively
reviewed. TMJ fossa air was present in 23 of 114 patients (20.2%) and was
bilateral in three patients. Only temporal bone fractures were
significantly (P less than .001) associated with TMJ fossa air. Temporal
bone fractures were observed at CT in 23 of 26 cases of TMJ fossa air, but
in three of 26 cases, TMJ fossa air was the only CT sign of clinically
apparent temporal bone fractures. TMJ fossa air is associated with acute
temporal bone fracture and may be the only CT sign of an otherwise
inconspicuous temporal bone fracture.
