Sideways position of the temporomandibular joint disk: coronal cryosectioning of fresh autopsy specimens.

Forty-five fresh temporomandibular joint autopsy specimens from elderly persons were studied with respect to the position of the disk in the sagittal and coronal planes. In the sagittal plane 80% of the joints showed superior disk position and 20% showed anterior disk position. In the coronal plane 62% showed superior disk position, 33% showed medial disk position, and 4% showed lateral disk position. There were no statistically significant associations between disk positions in the sagittal and coronal planes. The vertical distance from the central part of the condyle to the fossa was measured in the coronal sections and was smaller in joints with medial disk position than in joints with superior disk position. It was concluded that medial disk position is relatively frequent in elderly persons and that this condition might represent a variant of temporomandibular joint internal derangement.