目的 采用有限元法分析机械振动加速正畸牙移动中颌骨及牙周组织的应力分布，探讨静态正畸力和低值高频机械振动组合载荷（动静组合载荷）加速正畸牙移动的机理。方法 采用Mimics、SolidWorks、Geomagic 和ANSYS Workbench 等软件建立包括牙齿、牙周膜、牙槽骨松质骨、牙槽骨皮质骨的有限元模型，施加侧向静态正畸力、低值高频机械振动载荷，进行动力学分析。结果 牙槽骨及牙周组织的近远向正应力（Y向应力）分布可清晰区分张力区、压力区分，呈现周期性变化，并且其频率与加载的低值高频机械振动载荷一致；牙槽骨及牙周组织的米塞斯应力亦呈现周期性变化，但无法区分张力区和压力区。结论 在口腔正畸领域，近远向正应力为合适的力学激励表征量；侧向静态正畸力与低值高频机械振动载荷组合的动静组合载荷是一个可行的加速正畸牙移动的方法。本研究可对低值高频机械振动加速正畸移动提供指导。
Purpose The stress distribution of mandible bone and periodontal ligament during acceleration of orthodontic tooth movement by mechanical vibration was analyzed by using finite element method, and then mechanism of static-vibration coupled loading to accelerate orthodontic tooth movement was discussed. Methods The finite element model including tooth, periodontal ligament, cancellous bone and cortical bone was established by Mimics software，Solid Works software，Geomagic software and ANSYS Workbench software. Conventional static orthodontic force and low-load high-frequency mechanical vibration load were applied to the finite element model for dynamic analysis. Result The compression and tension zones of alveolar bone and periodontal tissue were identified based on y-normal stress distribution of alveolar bone and periodontal tissue, which was periodic with the same frequency as the applied low-magnitude high-frequency vibration. The von Mises stress of alveolar bone and periodontal tissue also showed periodic changes, but the compression and tension zones of alveolar bone and periodontal tissue were not identified based on von Mises stress distribution of alveolar bone and periodontal tissue. Conclusions In the field of orthodontics, y-normal stress was a reasonable mechanical stimulus, and static-vibration coupled loading was an effective method for accelerating orthodontic treatment. This study could provide guidance for mechanical vibration to accelerate orthodontic tooth movement.