Comparison of arthrotomographic and magnetic resonance images of 50 temporomandibular joints with operative findings.

Arthrotomography and magnetic resonance imaging (MRI) were carried out on 50 temporomandibular joints (TMJs) in 48 patients who were being considered for surgery for clinically diagnosed internal derangement. The patients presented over a 4-year period with pain and dysfunction which had failed to respond to conservative management. Open surgery was carried out on all TMJs and operative findings compared with the results of imaging. The clinical diagnosis of internal derangement was confirmed in every case by imaging and at surgery. Arthrotomography over-diagnosed non-reducibility of an anteriorly displaced meniscus and perforation. MRI over-diagnosed non-reducibility to a lesser extent and under-diagnosed perforation. MRI demonstrated neither bony changes nor adhesions. Dynamic arthrotomography produced the best images of meniscal derangement in function and the pre-arthrogram tomograms were the best indicator of osseous abnormality. Arthrotomography was the preferred imaging technique.