The articular disc position relative to the mandibular condyle in patients with skeletal class III malocclusion on MRI

Objectives: To investigate the status of the articular disc of the temporomandibular joint (TMJ) in patients with skeletal Class III malocclusion by means of magnetic resonance (MR) imaging. Methods: The position of the articular disc of the TMJ in closed- and opened-mouth positions was investigated in 50 adult patients with untreated skeletal Class III malocclusion by means of proton-density weighted MR imaging. Results: Of 100 joints of 50 patients, the lack of positional change of the articular disc relative to the mandibular condyle in both closed- and opened-mouth positions was observed in 62 joints. Conclusions: Although the cause of the lack of positional change of the disc relative to the condyle was unclear, this peculiar relationship of the disc and the condyle might possibly be associated with the function of the temporomandibular joint in skeletal Class III malocclusion.