Wall architecture and disc attachment of the human temporomandibular joint

Abstract

In an attempt to evaluate the potential behaviour of the temporomandibular joint wall during mandibular movements, joint specimens of 18 individuals, ranging in age from 15-45 years, were examined macroscopically and in the light microscope. The inner part of the joint wall was consistently formed by the superior and inferior lamina of the disc attachment. A distinct fibrous capsule existed in the posterior and lateral joint region, while anteriorly and medially, it could hardly be identified. The posterior attachment to the temporal bone of both the disc and capsule was clearly anterior to the squamotympanic and petrosquamosal fissure. A collagenous sheet inserting in and around these fissure was considered the deep lamina of the parotid-masseteric fascia. With reference to collagen arrangement, content in elastic fibres, and type of synovial lining, the postero-superior disc attachment appeared to be highly extensible, although not elastic enough to effectively pull the disc back upon posterior movements of the condyle. On the other hand, the latero-inferior disc attachment gave the impression of a rigid band well suited to drag the disc along with the condyle and still allowing condylar rotation. In addition, however, the postero-inferior disc attachment in combination with condylar rotation might also contribute effectively to the control of disc position on the moving condyle.