Establishment of biomechanical model of rigid internal fixation applied in the treatment of mandibular fracture

Purpose:A three dimensional finite element model which covers part of maxillary fracture, four kinds of mandibular fractures and rigid internal fixation is established in this paper, aiming at four parts where mandibular fractures occur frequently in clinical.Methods:CT images of the patients are imported to Mimics medical modeling software for jaw bone reconstruction. Maxilla and mandible structures of cortical bone and cancellous bone are distinguished respectively by adjusting the threshold, and their 3D modelsare established for editing and processing. File data are refined in Geomagic Studio, noise and sharp structures are removed to form Nurbs surface, thus igs files are exported.Files are imported to SIEMENS.PLM.NX.V to be stitched into the materialization model.And then the models are cut and assembled for the final fracture model which covers part ofmaxillary bone and the mandibular bone. Results:Themodel established for part ofmaxillary fracture, four kinds ofmandibular fractures at different parts and rigid internal fixationcan accurately reflect the shape and anatomical characteristics of jaw bone, and can provide precise geometric configuration and materials group for the later FEA analysis.Conclusion:Biomechanics analyses are applied between the implant sites of titaniumscrewand the direction of traction according to different kinds of mandibular fractures with FEAmethod, the results show that 3D finite element model of part of maxillary fracture, four kinds of mandibular fractures and rigid internal fixation has good geometry and mechanics similarity, which can be used to further explore the optimal implant site of titaniumscrewand the best traction direction of the rubber band for normal occlusion, to provide biomechanics theory basis for treatment of mandibular fractures by internal fixation with titanium plateand titanium screwbetween jaws.