目的 建立一种可以高效模拟正畸牙槽骨重建的方法。 方法 建立单颗门牙和磨牙的完整牙及牙周模型,模拟位移控制和力控制加载远中平移,基于外部重建理论和牙周膜应变理论,实现基于利用 ABAQUS 子程序UMESHMOTION 结合自适应网格技术(ALE),模拟牙槽骨重建过程。 结果 位移控制能够将初始远中位移加载量50 μm 通过骨重建算法实现,达到远中移动牙槽骨重建位移量 50 μm;力控制模式在施加 1 N 初始远中方向力并考虑最终衰减到 50% 初始力水平情况下,单、双根牙最终位移量分别为 67. 5、23. 77 μm。 两种模式均实现骨重建后牙周膜上绝对值最大主应力恢复到 0 应力水平,牙周膜达到新的力学平衡。 该算法可以在很短时间内很好模拟单、双根牙槽骨的重建过程。 控制成骨和破骨速率比为 7 ∶5时,单次迭代位移移动量控制在 0. 1 μm 能够得到稳定的重建过程。 结论 本方法首次实现了双根牙槽骨重建模拟,在位移和衰减力控制下均可以很好模拟牙槽骨重建的过程,为无托槽和有托槽正畸力系的设计提供有效工具。

Objective To establish a method for efficient simulation of orthodontic alveolar bone reconstruction. Methods A complete dental and periodontal model of a single incisor and molar was established, and displacement-controlled and force-controlled loading for distalization was simulated. According to the external reconstruction theory and the periodontal ligament (PDL) strain theory, alveolar bone reconstruction was simulated using the UMESHMOTION subroutine in ABAQUS combined with the adaptive mesh technology (ALE). Results In displacement-controlled mode, the initial distal displacement load of 50 μm could be achieved by the bone reconstruction algorithm to achieve distal alveolar bone reconstruction displacement of 50 μm. In force-controlled mode, the final displacement of the single-rooted tooth and double-rooted tooth was 67.5 μm and 23.77 μm, respectively, under the condition of applying the 1 N initial distal force and considering the final decline to 50% of the initial force level. In both modes, the absolute maximum principal stress on PDL returned to 0 stress level after bone reconstruction, and the PDL reached a new mechanical equilibrium. This algorithm could simulate the alveolar bone reconstruction process of single-rooted tooth and double-rooted tooth in a short period. At the osteogenesis-osteogenesis ratio of 7︰5, a stable reconstruction process could be obtained when the displacement of a single iterative displacement was controlled at 0.1 μm. Conclusions The proposed method achieved the the simulation of double-rooted alveolar bone reconstruction for the first time, and the process of alveolar bone reconstruction could be simulated well under displacement and decayed force controls, thereby serving as an effective tool for designing orthodontic force systems with or without brackets.

教育部科技发展中心,中国高校产学研创新基金(2021JH039),北京市科技新星计划交叉合作课题(20220484231)