Finite Element Analysis Of Biodegradable Materials For Mandibular Bone Defects

To investigate the feasibility of applying various personalized biodegradable materials for bone graft fixation in mandibular RBS-type bone defects, and to provide biomechanical insights for the design of personalized biodegradable materials in mandibular defect reconstruction. Finite element models of personalized internal fixation systems combined with fibula reconstruction for mandibular RBS-type bone defects were established. Finite element simulations were performed on personalized biodegradable materials (zinc alloy, magnesium alloy, and polylactic acid) to analyze the feasibility of their application in internal fixation for mandibular RBS-type bone defects, with titanium alloy as a comparative control. Biomechanical changes were investigated by evaluating whether the maximum stress on fixation plates and screws exceeded the materials’ ultimate strength and identifying stress concentration areas within the fixation system. The maximum stress of magnesium alloy and polylactic acid was higher than their yield strength. The maximum equivalent stress of zinc alloy internal fixation reconstruction plate and screws was lower than their yield strength. Compared with the titanium alloy group, the zinc alloy group had lower equivalent stress and equivalent strain, more uniform stress distribution, and lower stress shielding of bone. The chin, mandibular angle turning point, and condyle were the stress concentration sites of the reconstruction plate. Finite element simulations demonstrated that the mechanical properties of biodegradable zinc alloy are sufficient for fixation in fibula-reconstructed mandibular RBS-type bone defects, although reinforcement at stress concentration areas of the reconstruction plate is required.