Three-dimensional finite-element analysis investigating the biomechanical effects of human mandibular reconstruction with autogenous bone grafts

Purpose: To investigate the biomechanics of the mandible following reconstruction with autogenous bone grafts. Material: Computerized tomography scan images of a human mandible, fibula and iliac crest were collected and used to build models on a PC. Methods: Four finite-element analysis (FEA) models of mandibles reconstructed with autogenous bone were created. The principal stresses of marked points, the Von Mises stresses at anatomical index regions, and the force values of temporo-mandibular joints and masticatory muscles were calculated. Results: Compared with the normal mandible, the one repaired with a fibula had greater Von Mises stresses on the grafted bone; the one repaired with iliac crest bone had the similar distribution of the Von Mises stresses as in the normal mandible. The principal stresses in the autograft varied between tensile and compressive stresses from the right graft/bone binding interface to the left in all reconstructed mandibles. On the whole, the maximum Von Mises stress was greater on the mandible reconstructed with fibula than that reconstructed with iliac crest. Conclusion: Mandibles repaired with iliac crest grafts have more mechanical properties similar to normal than those repaired with fibula grafts. (C) 2006 European Association for Cranio-Maxillofacial Surgery.