The purpose of this study was to investigate the morphological changes on the mandibular fossa and articular eminence in case of TMJ articular disc perforation. The materials were the TMJs from 32 Japanese cadavers', including 7 perforated cases and 25 non-perforated cases. Morphological analysis was perfomed by macroscopic observation and the TMJ tomography. In addition, the morphology of the mandibular fossa was measured using the serial TMJ lateral tomographs. Morphological measurement of the mandibular fossa revealed significantly smaller values in the horizontal diameter, vertical diameter and front length in the of TMJ cases articular disc perfornation compared with the non-perforated cases by Student's t-test (P<0.01). Additionally, the larger the size of the perforation, the smaller the measurment values of the TMJ. In conclusion, these results suggest that the perforation of the TMJ articular disc leads to degenerative changes in the mandibular fossa and articular eminence.
