Nowadays, orthodontic treatment has become increasingly popular. However, the biological mechanisms of orthodontic tooth movement (OTM) have not been fully elucidated. We were aiming to summarize the evidences regarding the mechanisms of OTM. Firstly, we introduced the research models as a basis for further discussion of mechanisms. Secondly, we proposed a new hypothesis regarding the primary roles of periodontal ligament cells (PDLCs) and osteocytes involved in OTM mechanisms and summarized the biomechanical and biological responses of the periodontium in OTM through four steps, basically in OTM temporal sequences, as follows: (1) Extracellular mechanobiology of periodontium: biological, mechanical, and material changes of acellular components in periodontium under orthodontic forces were introduced. (2) Cell strain: the sensing, transduction, and regulation of mechanical stimuli in PDLCs and osteocytes. (3) Cell activation and differentiation: the activation and differentiation mechanisms of osteoblast and osteoclast, the force-induced sterile inflammation, and the communication networks consisting of sensors and effectors. (4) Tissue remodeling: the remodeling of bone and periodontal ligament (PDL) in the compression side and tension side responding to mechanical stimuli and root resorption. Lastly, we talked about the clinical implications of the updated OTM mechanisms, regarding optimal orthodontic force (OOF), acceleration of OTM, and prevention of root resorption.

如今，正畸治疗已变得越来越流行。然而，正畸牙齿移动（OTM）的生物学机制尚未完全阐明。我们的目的是总结有关 OTM 机制的证据。首先，我们介绍了研究模型，作为进一步讨论机制的基础。其次，我们提出了关于牙周膜细胞（PDLC）和骨细胞在OTM机制中的主要作用的新假设，并通过四个步骤总结了牙周膜在OTM中的生物力学和生物反应，基本上按OTM时间顺序，如下：（ 1）牙周组织细胞外力学生物学：介绍了正畸力作用下牙周组织非细胞成分的生物、力学和材料变化。(2) 细胞应变：PDLC 和骨细胞中机械刺激的感知、转导和调节。(3)细胞激活和分化：成骨细胞和破骨细胞的激活和分化机制、力诱导的无菌炎症以及由传感器和效应器组成的通讯网络。（4）组织重塑：受压侧和张力侧的骨和牙周膜（PDL）响应机械刺激和牙根吸收的重塑。最后，我们讨论了更新的 OTM 机制的临床意义，包括最佳正畸力 (OOF)、OTM 加速和牙根吸收的预防。