Biomechanical analysis of stress distribution changes in the maxillomandibular complex following surgical correction for facial asymmetry with reverse occlusal cant: A pilot finite element study.

The effect of surgical correction for facial asymmetry on stress distributions remains unclear, particularly in cases where the occlusal cant inclines toward the side opposite to the mandibular deviation (reverse occlusal cant). This pilot study aimed to investigate the biomechanical effects of surgical correction for reverse occlusal cant using finite element (FE) analysis. FE model of the maxillomandibular complex with a reverse occlusal cant inclined at 3-degree to the Frankfort horizontal plane was constructed. Surgical simulations using Le Fort I osteotomy and bilateral sagittal split ramus osteotomy were performed for cant corrections ranging from 0- to 5-degree in 1-degree increments. Stress analysis under masticatory loading was conducted, and von Mises stress distribution around the temporomandibular joint (TMJ) and occlusal surfaces was compared across models. Cant correction from 0- to 3-degree revealed a decreasing trend in stress around the TMJ, while from 3- to 5-degree resulted in an increasing trend. Conversely, stress on the occlusal surface showed an opposite pattern, with both increases and decreases inversely related to TMJ stress. The 3-degree correction model demonstrated the lowest stress and minimal left-right stress imbalance around the TMJ, while exhibiting the highest stress and the largest distribution area on the occlusal surface. These findings suggest that surgical cant correction significantly alters stress distribution around the TMJ and occlusal surfaces in patients with skeletal asymmetry and reverse occlusal cant.