Abstract: PURPOSE : To evaluate the value of magnetic resonance image (MRI) on the diagnosis of perforation of the temporomandibular joint (TMJ). METHODS : Consecutive 1845 patients (2524 TMJs) diagnosed as temporomandibular disorders (TMD) were collected from April 1st, 2003 to March 1st, 2010 in our department. All the patients were examined by MRI and treated by arthroscopy or operation. The findings of interpreting MRI were recorded as positive, suspicious and negative according to the MRI radiographic criteria. After comparing the findings of MRI with those of arthroscopy or operation, the numbers of true positive, true negative, false positive and false negative were obtained. Through SPSS16.0 software package, receiver operator characteristic curve (ROC curve) was made with 1-specificity as abscissa and the sensitivity as ordinate, and the area under the ROC curve was calculated. According to the area, the diagnostic value of MRI was evaluated. RESULTS : According to the criteria above, we found 189 TMJs were positive, 197 TMJs were suspicious, and 2138 TMJs were negative. After comparing the findings of MRI with those of arthroscopy or operation, true positive in 102 TMJs and false positive in 87 TMJs were detected among 189 positive TMJs, perforation in 42 TMJs and no perforation in 155 TMJs were detected among 197 suspicious TMJs, and true negative in 2075 TMJs and false negative in 63 TMJs were detected among 2138 negative TMJs. The area under ROC curve was 0.808(0.77,0.85)(P<0.05). CONCLUSIONS : It is concluded that the diagnostic accuracy of MRI was good, but the accuracy depends on both whether there was joint fluid and the experience of the doctors.

Key words: Temporomandibular joint, Perforation, MRI