Abstract
The purposes of this study was to deduce a typical MR image of the temporomandibular joint with the disc perforation from evaluation of a number of similar cases and to investigate the predictability of MR imaging of disc perforation.
Material and methods: The first pair of subject groups used for comparison were 50 TMJs with perforation and 50 TMJs without perforation. The second pair of compared groups were 10 TMJs with perforation and 10 TMJs without perforation. All TMJs were examined by MR imaging at 0.3 Tesla (MRP-7000 HITACHI MEDICO, Tokyo). The case of disc perforation was judged by double-contrast arthrotomographic examination. Typical MR images of the TMJ with disc perforation were determined from the first pair of subject groups. The second pair of subject groups were used for determination of diagnostic accuracy on the basis of the typical MR findings of perforation discs, such as sensitivity, specificity, and positive and negative predictive values.
Results: The typical MR findings of a perforated disc had marginal proliferation of the condyle, surface irregularity of the area ranging from eminence to fossa and disc deformation such as biconvex. Diagnostic accuracy of the findings was 75 to 80 % from a single finding and 85 % from multiple findings.
