Normal and abnormal temporomandibular joint disc and posterior attachment as depicted by magnetic resonance imaging in symptomatic and asymptomatic subjects.

PURPOSE: This investigation provides a detailed assessment of the morphologic and signal intensity changes of the temporomandibular joint disc and posterior disc attachment as depicted by magnetic resonance imaging in symptomatic versus asymptomatic subjects.

PATIENTS AND METHODS: Sixty-one asymptomatic volunteers and 58 symptomatic subjects were imaged using a 1.5 tesla magnetic resonance system utilizing bilateral high-resolution surface coils with the jaw in the closed and maximal opened position. Disc shape and signal intensity characteristics were tabulated along with a detailed assessment of the various regions of the disc posterior attachment in a blinded fashion as to symptomatology.

RESULTS: Deformity of the disc was noted in 34 of 116 (29.3%) of joints in patients and in 5 of 122 (4%) of joints of volunteers ( P < .0005; chi-square test). There was a large region of increased signal intensity in the posterior band of the disc on proton- or T1- weighted images in 13 of 116 (11.2%) joints in patients versus 1 of 122 (0.8%) joints in asymptomatic subjects ( P < .0005). In all joints with disc displacement with or without reduction, the temporal posterior attachment was visualized in only 43.5% in the closed jaw position ( P < .0005 versus all normal joints) and in 30.4% ( P < .0005 versus all normal joints) in the open jaw position.

CONCLUSION: Magnetic resonance allows an in vivo characterization of the fine structural details of the disc and the disc posterior attachment, separating normal from internal derangement temporomandibular joints.