MRI assessment of temporomandibular disc position among various mandibular positions: a pilot study.

PURPOSE: The aim of this pilot study was to assess temporomandibular joint disc movement relative to the condyle among centric relation (CR), physiologic rest position (PRP), and maximal intercuspation position (MIP) in healthy patients without signs or symptoms of any temporomandibular disorder. The hypothesis was that as the condyle rotated clockwise or translated anteriorly, the disc would also move in an anterior direction. MATERIAL AND METHODS: Magnetic resonance images were obtained on 20 volunteers in CR, physiologic rest, and MIP. Three investigators measured the location of the disc among the different mandibular positions. RESULTS: Disc location differences between CR and PRP exhibited the widest range of measurement. The largest amount of disc protrusion relative to the condyle was found between CR and PRP on the right side. The largest amount of disc retrusion relative to the condyle was found between CR and MIP on the right side. The hypothesis was not supported by the results. CONCLUSIONS: According to the results of this pilot study, the direction of movement of the temporomandibular disc does not correlate with the rotational movement of the condyle in hinge positions. CLINICAL IMPLICATIONS: Increased knowledge of temporomandibular disc movement among various mandibular positions in asymptomatic patients may help clinicians recognize deviations in symptomatic patients.