正畸微植体动态植入过程有限元数值仿真

Dynamic Implantation Process of Orthodontic Micro-Implant:A Finite Element Numerical Simulation

目的 建立自攻型正畸微植体动态植入模型,研究微植体动态植入过程中周围骨应力分布情况。方法 基于CBCT数据重建口腔三维模型;利用ABAQUS软件建立微植体和种植区域骨组织的有限元模型;使用三维动态有限元方法,对微植体受40 N轴向推进力、0.5 r/s恒定转速植入骨内的过程进行仿真分析。结果 成功建立了自攻型正畸微植体动态植入过程的三维有限元模型、结果可视化展示了微植体动态植入过程;结果发现植入阶段和螺纹位置对骨应力分布影响明显且不同骨质应力状态差异明显:在植入过程中,皮质骨最大应力为167 MPa,稳定阶段最大应力为50 MPa;松质骨最大应力为30 MPa。结论 植入阶段和螺纹位置对骨应力分布影响明显;皮质骨和松质骨应力差异明显。可以利用应力特征判断骨质类型,通过种植体周围的骨应力分布情况判断颌骨是否处于合适的种植状态。

Objective To study the stress distributions of the surrounding bone during the dynamic implantation of micro-implants,a finite element model of self-attacking orthodontic micro-implant dynamic implantation was proposed and established.Methods A three-dimensional(3D)oral model was constructed using CBCT data.The local model around the implant and the 3D finite element model of the micro-implant were established using ABAQUS software.The micro-implant was implanted into the jaw with an axial propulsion force of 40 N at a constant speed of 0.5 r/s.Results The 3D finite element model was successfully established to simulate dynamic self-attacking orthodontic micro-implant implantation in the jaw bone.The results showed that implantation stage and thread position had significant effects on bone stress distribution and the stress states of different bones had obvious differences:the maximum stress on the cortical bone was 167 MPa,and the maximum stress at the stable stage was approximately 50 MPa.The maximum stress on cancellous bone was 30 MPa.Conclusions The implantation stage and thread position have apparent influences on stress distribution.The stress difference between the cortical and cancellous bones was evident.The stress characteristics can judge the bone type,and whether the jaw is in a suitable implantation state can be judged by the bone stress distributions around the implant.