The purpose of this study is to develop a three-dimensional (3D) finite element model of the temporomandibular joint (TMJ) and to further investigate the stress distributions after occlusal splint therapy. Six patients with anterior disc displacement without reduction were reconstructed before and after six months of occlusal splint treatments from computed topography (CT) and magnetic resonance imaging (MRI). One must focus on the magnitude and location of the maximum stresses under physiological loading. In the 3D model studies, each mandibular condyle, disc, and articular eminence was divided into five regions: anterior, posterior, central, medial, and lateral. The results of this study show that the abnormal von Mises stresses occurred in the condyle during jaw closing, and overloading of the anterior condyle and posterior disc during jaw opening occurred before treatment. Stresses of all regions became well distributed after treatment, and an approximately 30% stress reduction in the condyle and a 35% stress reduction in the disc were found during jaw opening (p < 0.05), a remarkable difference. This result shows the potential clinical benefits in terms of proven superior biomechanical behavior according to occlusal splint treatment.
Ming-Hung Tsai, Chi-Ming Wu, Ming-Hong Lin, Ching-Zong Wu, Han-Yi Cheng and Keng-Liang Ou