Abstract
Purpose: A three-dimensional finite element model of the mandible including the temporomandibular joint (TMJ) was constructed to examine the biomechanical influences of changes in the mandibular morphology on TMJ. This study investigated the influences of changes in the horizontal condylar angle and gonial angle on the condylar displacement.
Methods: Based on a juvenile human dry skull specimen and the specimen containing the TMJ, which was sliced into serial sections, a numerical model of the mandible, including the TMJ, was developed. In this model, the ramus of the mandible is modeled by rigid beam elements, and thus the horizontal condylar angle and the gonial angle can easily be changed. The direction of the condylar displacement was analyzed with respect to changes in the horizontal condylar angle and gonial angle.
Results:
1. In changes in the horizontal condylar angle, the direction of the condylar displacement was influenced in unilateral occlusion, but was not influenced in bilateral occlusion.
2. When the gonial angle was opened, the direction of the condylar displacement migrated to the anterior. On the other hand, when the gonial angle was narrowed, the direction of the condylar displacement migrated upward.
Conclusions: It was found that changes in the horizontal condylar angle and gonial angle influenced the direction of the condylar displacement.
