Synovial chondromatosis of the tempromandibular joint: Relationship between MRI information and potential aggressive behavior

Purpose To evaluate the types of synovial condromatosis (SC) of tempromandibular joint (TMJ) on MRI and their potential aggressive behavior. Methods 144 patients with pure SC of TMJ were included in. On MRI, 3 types of the lesion included loose body, homogeneous mass, and mixture of both loose body and homogeneous mass. Bony evaluations included 4 stages of erosion: without erosion, chondral breakdown, bony absorption and bony perforation. Results 47 (32.6%) cases were categorized in the type of loose body, 71 (49.3%) cases in the type of homogeneous mass, and 26 (18.1%) cases in the type of mixture. 80% of bony perforation belonged to the type of homogeneous mass and 20% belonged to the type of mixture. 2 patients were found recurrence. Conclusion The types of homogeneous mass and mixture of both on MRI were more aggressive. Homogeneous mass with bony erosion on MRI had potential recurrence.