2016 Volume 39 Issue 1 Pages 9-14
The aim of this study was to compare the mechanical behavior of two different sizes of maxilla with obturator prosthesis by the three-dimensional finite element method （3D FEM）. 3D FEM models of an obturator prosthesis with Aramany class Ⅳ defect maxilla and a removable prosthesis with non-defect maxilla were constructed with mucosa, alveolar bone, periodontal ligament, 24, 25, 26, 27 teeth, and double Akers clasps. In the boundary condition, the base area of alveolar bone was fixed in all directions. A vertical force of 30 N was applied to the center on the equivalent of 14, 15, 16, 17 teeth （Total: 120 N）. Maximum values of stress at the supporting bone in the Aramany class Ⅳ model were higher than those in the removable partial denture model. The direction and amount of displacement were different, and were related with bone size. A higher value of displacement was observed in the Aramany class Ⅳ defect model, and rotational motion was also observed. A higher stress value and wider stress distribution on the alveolar bone were observed in the Aramany class Ⅳ maxillary defect model. Rotational motion of the obturator prosthesis was observed in the Aramany class Ⅳ defect model.
