Correlation among the changes observed in temporomandibular joint internal derangements assessed by magnetic resonance in symptomatic patients.

PURPOSE: The objective was to assess possible correlations among the anatomy and position of the articular disc, the morphology of the articular eminence and of the condyle, and the presence of joint effusion.

MATERIALS AND METHODS: Magnetic resonance images of 142 joints of symptomatic patients were assessed. The articular disc was classified as normal, elongated, or folded; displacement was classified as normal, anterior with reduction, anterior without reduction, or posterior, lateral, or medial; the condyle was classified as rounded, convex, flattened, or angulated; and the articular eminence was classified as box, sigmoid, flattened, or deformed.

RESULTS: The most frequent forms of the articular disc, articular eminence, and condyle were normal, box, and flattened, respectively. Associations were confirmed between the form of the articular disc and its anterior and lateral positions; between the form of the condyle and an anterior position of the disc; and between the form of the articular eminence and the form of the disc. The form of the articular eminence was the only variant that was not associated to the presence of joint effusion.

CONCLUSIONS: Magnetic resonance imaging allowed the clear observation of articular structures, without attributing a cause-and-effect relation. The prevalence of changes observed was associated with the diagnosis of internal derangement and was statistically proved.