Elucidation of the effects of periodontal pathogenic factor and excessive mechanical stress on signaling pathway of orthodontic tooth movement

我们发现，IL-1 β的组成型表达是必不可少的诱导表达MIP-2和MCP-1在成骨细胞的机械应力的方式依赖于MyD 88，IL-1受体和TLR的衔接分子。提示MyD 88信号通路参与了正畸治疗早期的骨重建过程。高浓度的IL-1 β可促进机械应力诱导的成骨细胞炎症反应。临床研究发现，牙根长度与咬合接触丧失有关。此外，部分不良骨桥在植骨后的早期阶段通过正畸牙齿移动得到改善。结果提示，咬合力和机械应力所产生的功能应力可能促进牙根长度的形成和骨改建。

We found that the constitutive expression of IL-1beta is essential for the induced expression for MIP-2 and MCP-1 in osteoblasts by mechanical stresses in a manner dependent on MyD88, an adaptor molecule for IL-1 receptor and TLRs. Thus, it is suggested that MyD88 signaling pathway is involved in bone remodeling in the early phase of orthodontic treatment. Our findings also indicated that high level concentrations of IL-1beta may promote inflammatory responses of osteoblasts induced by mechanical stress. In the clinical research, it was found that the dental root length was related to the loss of occlusal contact. Additionally, some of the poor bone bridges were improved by orthodontic tooth movement in the early phase after bone graft. These results suggested that the functional stress by occlusal force and mechanical stress may promote root-length formation and bone remodeling.