Three Dimensional Finite Element Analysis Of Upper Dentition With Retractive Force

[Objective] To construct the 3-D finite element model of dentofacial complex with the original DICOM data of CT and investigate the biomechanics characters preliminarily with different direction and the magnitude of the retractive forces to maxillary complex of human being.[Materials and Methods]1. The establishment of 3-D finite element model of maxillary complex:spiral CT scaned,then CT workstation outputed CT images in DICOM format to personal computer,using ANSYS and Mimics software established the 3-D finite element model of maxillary complex of human being.2. 3-D finite element analysis of maxillary complex with backward retractive forces:based on the establishment of maxillary complex 3-D finite element model of human in experiment 1. Then the ANSYS software was used to analyse stress distribution and displacement of upper dentition.[Results]1. The establishment of maxillary complex three-dimensional finite element model:model,which was made up of 350125 units and 583391 nodes,included maxillary,arch wires,teeth of 14, maxilla cavity structures.Model and modeling were of the same size with a good geometric similarity.It had scalability which made it possible to attach brackets and wires, implants to start related studies.2. High and low traction:Changing the angle of traction along the Y axis, the displacement'changes of the points (U1,U2,UC,U6,A) in the Z axis was most effective, in the Y-axis were more effective,in the X axis were almost no effect.when the angle value,points moved to the negative direction of the Z axis, greater than 45 angle, points moved to the position direction of the Z axis. When the traction angle between 0 to 15 angle,clockwise rotation directon will occurred on maxilla. occlusional plane angle 45-60 angle, the counterclockwise rotation would happened on occlusional plane.30 angle, the occlusional plane shows movement without any rotation.3. effects on upper dentition with retraction force:with the increase of the value, each landmarks (U1,U2,UC,U6,A)showed larger displacement,values of displacement and force the size suggested a linear relationship,with the increase of the force value displacement increased significantly,showing that there were an obvious backward effect on upper dentition.2N, the major principal stress was light.[Conclusion]1. With the traction angle between 0 to 15 angle,clockwise rotation directon will occurred on occlusional plane,45-60 angle, the counterclockwise rotation would happened on.occlusional plane.30 angle, the occlusional plane shows bodily movement without any rotation.2. values of displacement and force the size suggested a linear relationship,with the increase of the force value displacement increased significantly,showing that there were an obvious backward effect on.occlusional plane.2N, the major principal stress was light.