Morphological changes of the articular eminence and the anterior disc displacement in youngsters

In this study, we focused on the relationship between the morphological features of the articular eminence and the presence of the anterior disc displacement on MR image in youngsters. We classified the morphology of the articular eminence into four categories, flattened, sigmoid, box and deformed on MR image. The results of this study indicated that morphological features of the articular eminence on serial MR images were related to the articular disc configuration, which were the presence of the anterior disc displacement in the intercuspal position, the levels of the anteriorly displaced disc in the intercuspal position and the presence of the reductions of the anteriorly displaced disc in the maximum opening mouth position. There were statistically significant differences in the distribution of the morphology of the articular eminence between normal disc position and anterior disc displacement in all of three sagittal planes. There were statistically significant differences in the morphology of the articular eminence among the levels of the anteriorly displaced disc in central and lateral planes. There was statistically significant difference in the distribution of the morphology of the articular eminence between presences of reduction of the anteriorly displaced disc in the central plane. We concluded that the morphological feature of the articular eminence continuously changes as dental arch develops in the time with temporal instability of mixed dentition, and seems to have positive correlation to the anterior disc displacement.