微小种植体正畸支抗生物力学的三维有限元分析

A three-dimensional finite element analysis for the biomechanical characteristics of orthodontic anchorage micro-implant

目的:建立微小种植体正畸支抗的三维有限元模型,分析以不同倾斜角度植入微小种植体时,种植体-骨界面的生物力学变化,为微小种植体正畸支抗系统的设计和临床应用提供理论依据。方法:利用ANSYS6.1大型通用有限元分析软件,建立倾斜角度分别为30°、40°、50°、60°、70°、80°、90°的7个微小支抗种植体模型。分析在200g水平力作用下,种植体-骨界面应力及位移的分布情况。结果:随种植体倾斜角度的增大,种植体颈部的Von-Mises应力值峰值分别为1.0792、1.0104、0.8848、0.8181、0.7583、0.6339及0.5608MPa。位移峰值分别为5.5513、4.9900、3.7419、3.1264、2.5874、1.3624及0.8027μm。结论:微小种植体可在任何倾斜角度上承载200g的水平向正畸力。增加种植体的倾斜角度,可以提高其承载水平向正畸力的能力,提示临床应选择垂直于颊侧牙槽骨的方向植入微小支抗种植体。

PURPOSE:To establish a three-dimensional finite element model for orthodontic anchorage micro-implant,and to analyze the influence of different titled angles on the biomechanical characteristics of orthodontic anchorage implant-bone interface. METHODS: ANSYS( Analysis System)finite element analysis software was used to perform the finite element modeling of the micro-implant with 7 different tilted angles, including 30°, 40°, 50°, 60°, 70°, 80° and 90°. A simulated orthodontic force ,which was 200 grams ,was loaded mesiodistally to the mathematical models.The stress and displacement distribution on the implant-bone interface were analyzed. RESULTS: As the titled angle increased , the Von-Mises stress at the cervix of the implants were 1.0792, 1.0104, 0.8848, 0.8181, 0.7583, 0.6339 and 0.5608MPa ,while the displacement were 5.5513, 4.9900, 3.7419, 3.1264, 2.5874, 1.3624 and 0.8027μm?CONCLUSION: The micro-implant can be safely loaded with 200 grams of mesiodistal orthodontic force .The increase of the titled angle can efficaciously enhance the ability,implicating that the implant can bear a mesiodistal orthodontic force,vertical angle should be chosen when the micro-implant is embedded. Supported by Natural Science Foundation of Liaoning Province (20042076).