Three-dimensional Animation of the Temporomandibular Joint

The aim of this investigation was to develop a method to reconstruct three-dimensionally the temporomandibular joint (TMJ) by means of magnetic resonance (MR) tomograms and to combine this reconstruction with jaw motion data, recorded with six degrees of freedom by means of the opto-electronic system Jaws-3D, in order to analyse the movement of the whole condyle within the fossa during opening and closing, protrusive and laterotrusive movements. The three-dimensional reconstruction of the TMJ was calculated and animated on a graphics workstation. The condyle - fossa distance during jaw movements was computed for every condylar point and visualized by shading the surface of the condyle with pseudo colors. Furthermore, the location of the minimum condyle-fossa distance was calculated and displayed in a plane graph representing the condylar surface. For five subjects without any past or present history of myoarthropathies of the masticatory system the resulting patterns were analyzed and compared.