Finite element analysis of stress distribution on reconstructed mandibular models for autogenous bone grafts

BACKGROUND: There are several challenges in terms of mandibular reconstruction. The defect size, graft materials, and plate combinations should be taken into consideration in surgical planning. OBJECTIVE: The aim of this study was to evaluate the effect of different reconstruction variations on the stress distribution of segmental resected mandibles with two different defect sizes using finite element analysis (FEA). METHODS: Computerized tomography images of a human mandible, fibula, and iliac crest were used as references to build three-dimensional (3D) models on a PC. The virtual plates and screws were used to simulate reconstruction of the mandibular defects. The models were divided into two groups based on the longitudinal defect size. Different osteosynthesis variations and autogenous graft material combinations were used to reconstruct the mandibles. RESULTS: In all models, higher von Mises stress values occurred on the mandibles reconstructed with the fibula than those with the iliac crest. Fixation of the bone grafts with a reconstruction plate for the 10-mm defects and using a mini-plate in addition to the reconstruction plate for the 30-mm defects decreased stresses on the grafted bones. CONCLUSIONS: Mandibular reconstruction with the iliac grafts is biomechanically superior to that with the fibular grafts. In addition, osteosynthesis methods and the defect size affect the stress distribution.