Elusive "stuck" disk in the temporomandibular joint: diagnosis with MR imaging.

Abstract

To determine the incidence of a "stuck" disk and its importance in the overall scheme of internal derangement. Magnetic resonance (MR) images of 212 temporomandibular joints (TMJs) in 106 symptomatic patients were obtained and reviewed. Image analysis included assessment of disk position; disk mobility; and degree of condylar translation, with or without disk recapture in joints with displaced disks. Of the 127 joints with disks in a normal position, 94 had mobile disks and 23 had stuck disks. Ten joints revealed no condylar translation, which precluded assessment of disk mobility. Of 85 joints with displaced disks, 67 joints showed mobility, with recapture in 25 and no recapture in 42. Significant correlation existed between disk mobility and degree of condylar translation (P < .001). The TMJ disk may be stuck in a normal or displaced position and limits the normal degree of condylar translation, leading to restricted jaw opening. Recognition of a stuck TMJ disk could alter patient care.