INTERNAL DERANGEMENT OF THE TEMPOROMANDIBULAR-JOINT MR-IMAGING FOR STAGING

On the basis of MR imaging studies in 150 temporomandibular joints (TMJs) a classification system for internal derangement of the TMJ was defined. Clinically, internal derangement is characterized by disc displacement and disorders of the mandibular condyle. MR imaging enables a differentiation of early stages (I, II) with disc displacement, the intermediate stage (III), and the later stages (IV, V) with osseous destruction. Optimal diagnostic results (n = 140) allowed the use of proton-density sequences in both open and closed joint positions (TR/TE = 1000/28). Dynamic imaging of the TMJ was performed using fast-gradient echo sequences and a self-developed hydraulic opening deuce (n = 20). MR imaging has proved to be the method of choice for the pre- and post-therapeutic evaluation of internal derangement of the TMJ.