Three-dimensional finite element analysis of the human temporomandibular joint disc

A three-dimensional finite element model of the articular disc of the human temporomandibular joint has been developed. The geometry of the articular cartilage and articular disc surfaces in the joint was measured using a mag netic tracking device. First, polynomial functions were fitted through the coordinates of these scattered measurements. Next, the polynomial descripti on was transformed into a triangulated description to allow application of an automatic mesher. Finally, a finite element mesh of the articular disc w as created by filling the geometry with tetrahedral elements. The articulat ing surfaces of the mandible and skull were modeled by quadrilateral patche s. The finite element mesh and the patches were combined to create a three- dimensional model in which unrestricted sliding of the disc between the art iculating surfaces was allowed. Simulation of statical joint loading at the closed jaw position predicted that the stress and strain distributions wer e located primarily in the intermediate zone of the articular disc with the highest values in the lateral part. Furthermore, it was predicted that con siderable deformations occurred for relatively small joint loads and that r elatively large variations in the direction of joint loading had little inf luence on the distribution of the deformations. (C) 2000 Elsevier Science L td. All rights reserved.