SIZE AND LOCATION OF THE HUMAN TEMPOROMANDIBULAR-JOINT

The literature abounds with conflicting data. on various morphometric aspects of the temporomandibular joint (TMJ). The purpose of this stud y was to observe the effects of sex, ethnic group, and edentulism on T MJ osseous morphology and to define possible factors which might influ ence variation in this structure. TMJs and related craniofacial struct ures were measured directly on 229 dry skulls and matching mandibles. Analysis of variance, principal component analysis, and cluster analys is were performed. Our results indicate that 1) the anteroposterior-re lated TMJ dimensions are independent of sex, ethnic group, and edentul ism; 2) the transverse TMJ dimension is related to cranial breadth mea sures; and 3) the projected distance, along a midsagittal plane, betwe en the TMJ and foramen magnum is independent of sex, ethnicity, and ed entulism. It is our assertion that the TMJ must not be considered as a single morphological structure but rather viewed as a functional unit with component parts which are subordinate to completely different se ts of influences. (C) 1996 Wiley-Liss, Inc.