Figure 2: Finite element analysis model of temporomandibular joint (TMJ) stress. (a) Three-dimensional finite element mesh of the TMJ, including the mandible, disc (i), cartilage (ii), condyle (iii), and coracoid process (iv), with the mandible angle fixed (v) and alveolar ridge loaded by two-dimensional occlusal force vectors (vi). (b) State of stress in an orthotropic element. Each of the three material axes was assigned a value for the elastic modulus ( ), and each of the three planes defined by those axes received values for the shear modulus ( ) and Poisson’s ratio ( ). Thus, one principle stress ( ) and two shear stress ( ) values could be calculated from each plane of the element. 1, 2, and 3 indicate the same corresponding directions as in Figure 1. (c) Twenty-nine observation points map the TMJ for stress value collection.