Biomechanical Analysis Of The Human Temporomandibular Joint During Clenching With The Three-dimensional Meshless-finite Element Coupling Method

The temporomandibular joint(TMJ)is the most complicated and subtlly used of all the body joints.In TMJ,the articular disc is the most important structure.Therefore,the biomechanical environment in the TMJ,especially the articular disc,is a key to understand the origin and progression of temporomandibular disorders(TMDs).Partâ… The reconstruction of three-dimensional meshless-FE coupling model of TMJMaterials and Methods:The three-dimensional finite element model of the mandible including the TMJ was identical to that used in the team of Yin Xinmin.As the TMJ was bilaterally symmetrical,only the left part was included in this study.This three-dimensional finite element model was imported into TrueGrid,a finite element pre-processing software,for hexahedron meshing except mandible and lower teeth for tetrahedron meshing and then opened in Marc2003.It was conserved as model 1. Afterwards,the three-dimensional finite element model,which was established by the team of Yin Xinmin,was imported into Hyper-Mesh, another finite element pre-processing software,only for tetrahedron meshing.The elements of glenoid fossa,condyle,mandibular rames and the nodes of the surface of articular disc were kept invariable and interior of articular disc was discretized with only a set of nodal points but without any mesh constraints in ANSYS8.0.Then a three-dimensional meshless-FE coupling model was established and conserved as model 2.Results:Model 1 was a three-dimensional finite element model including glenoid fossa,articular disc,condyle and mandibular rames,containing 33061 nodes and 105846 elements.Model 2 was a three-dimensional meshless-FE coupling model,containing 9354 nodes(consisting of 182 meshless nodes)and 36647 elements.Conclusion:On the basis of finite element model,a three-dimensional meshless-FE coupling model of TMJ can be constructed more precisely by means of technology of discretizing a set of nodal points.Partâ…¡:Biomechanical analysis of the human TMJ with the three-dimensional meshless-FE coupling methodMaterials and Methods:According to the boundary constrained condition,the simulations to two models started with the jaw in closed position.The three-dimensional finite element model was discriminated in Marc2003 using the finite element post-processing software.The three-dimensional meshless-FE coupling model was analyzed using a self-developed processor.The result data were input into the Ansys8.0 and then the stress distribution contours of the TMJ were obtained. Results:The stress distribution results between meshless-FE coupling methods and finite element method were compared and analyzed.They were found in very good agreement.The values of the Von Mises stresses were less on the glenoid fossa than on the condyle and the articular disc.In the articular disc,the high Von Mises stresses were seen at the intermediate zone and the bilaminar region.But the result of meshless-FE coupling method is more refined.Conclusion:The stress results between meshless-FE coupling methods and finite element method were found in very good agreement.But result of meshless-FE coupling method is more refined.The meshless-FE coupling method is able to be successfully applied in other fields within biomechanics.