Finite element stress analysis of Aramany class I maxillectomy defect with single- and two-piece closed bulb obturators.

AIM: To evaluate the stress on the surrounding structures of Aramany class I maxillectomy defect restored with different obturator prostheses. METHODS AND RESULTS: Definitive three-dimensional (3D) finite element (FE) model of Aramany class I defect rehabilitated with single- and two-piece closed bulb obturator prostheses was constructed based on patient computed tomography (CT) using a software. Unilateral defect restored with tripodal design single-piece closed bulb obturator was used as FE model 1- and two-piece magnet retained closed bulb obturators as FE model 2. Finite element analysis (FEA) with three different load (150 N, 200 N and 250 N) applications was used to calculate the equivalent von Mises stress. A least stress value of 62.28 MPa was observed in two-piece closed bulb design with 150 N force, and highest stress value of 104.15 MPa was observed in single-piece obturator with application of 250 N force. CONCLUSION: Minor difference in stress distribution pattern was observed between single-piece obturator and two-piece obturator, and stress value was comparatively lesser in two-piece than single-piece obturator. The stress pattern, distribution and numerical values increased with increase in magnitude of forces. More stress was observed on the lateral slopes of obturator closer to defect than in other areas of the obturator.