MR imaging of the temporomandibular joint.

MR imaging allows detailed evaluation of temporomandibular (TMJ) anatomy because of its inherent tissue contrast and high resolution. Joint biomechanics can be assessed through imaging patients in the closed and open jaw positions. Despite the accuracy of MR imaging in detecting disc position, results must be interpreted together with clinical findings, because an anteriorly displaced disc can be seen in up to one-third of asymptomatic patients, and a normal disc position can be seen in up to one-quarter of symptomatic patients. Interpretation of MR imaging requires knowledge of the normal anatomy and an understanding of normal and abnormal biomechanics.