Methods: Three-dimensional images of the skull were reconstructed from CT images of patients with skeletal deviated occlusion by bone structure analysis software (TRI/3D-BON, RATOC System Engineering). Then, a finite element analysis software (TRI/3D-FEM, RATOC) was used to calculate the mechanical stress in the maxilla and mandible generated by simulated mastication loads. The total applied load (100N) was divided to 8 muscles depending on each cross-section ratio. The working points were set at the insertion location of the masticatory muscles and the load directions followed the direction of each muscle.
Results: High maximum principal stresses in the maxilla and the mandible were distributed similarly on both (deviated and non-deviated) sides. However, high minimum principal stresses tended to concentrate in the buccal alveolar bone surface of the deviated side of the maxilla and the non-deviated side of the mandible.
Conclusions: The results of this study suggest that asymmetric stress distribution in both the maxilla and mandible during mastication could be one of the exacerbation factors of skeletal deviated occlusion.
Acknowledgement: This study was supported by a Grant-in Aid for Scientific Research(C)(No. 22592281), from the Japan Society for the Promotion of Science.