Determination of the radiographic position of the temporomandibular joint disk.

We describe a method of measuring displacement and reduction of the temporomandibular joint (TMJ) disk that makes use of reproducible geometric measurements from radiographs in the sagittal plane. This procedure leads to a simple quantitative classification scheme for condyle-disk-fossa/eminence relationships. The method was applied to microscopic sections of 12 human TMJs and then to 30 complete lateral corrected cephalometric arthotomographic studies of the TMJ. Statistical analyses of the classification scheme confirm that it is highly significant and consistent with clinical diagnoses.