MAGNETIC-RESONANCE EVALUATION OF THE TEMPOROMANDIBULAR-JOINT DISC POSITION AND CONFIGURATION

Although magnetic resonance imaging (MRI) is the modality of choice fo r evaluation of TMJ disc position, it is sometimes difficult to determ ine when it is displaced or reduced. The MR images of 273 Patients wit h a clinical diagnosis of TMJ disorders were assessed for disc positio n and configuration. Most (90-97%) of the slightly anteriorly displace d discs were reduced to the normal position in the open-mouth position . However, the greater part (76%) of the distorted discs was completel y displaced anteriorly and without reduction. Since no distorted discs were found in the normal disc position, we conclude that discs are di storted after displacement.