To test the hypothesis that flattening of the slope of the articular eminence occurs with progressive internal derangement (ID) of the TMJ.
MR images of 170 TMJs in 130 patients with proven disk displacement were studied. The correlation between the prevalence of a flattened articular eminence and radiological stage of ID was analysed.
The prevalence of a flattened articular eminence was significantly higher in the joints with advanced ID (Mann-Whitney's U-test, P < 0.05).
It appears that a flattening of the slope of the articular eminence occurs as a result of remodeling or degenerative changes secondary to ID.