目的 观察大鼠正畸牙移动牙槽骨的改建及叉头框蛋白O1（forkhead box O1, FOXO1）的表达改变，初步探讨FOXO1在正畸力介导的牙槽骨改建中的作用。方法 构建大鼠牙移动模型，左侧上颌第1磨牙在50 g力作用下近中移动。分别于牙移动1、3、7 d处死大鼠。通过HE染色及免疫组织化学法观察牙移动不同时间点第1磨牙根分叉区牙槽骨的改建及FOXO1的表达水平。结果 正畸力作用后，大鼠上颌第1磨牙不断近中移动。牙移动组根分叉区牙槽骨内破骨细胞较对照组明显增加，牙移动第3 d时破骨活性最强。加载正畸力后，根分叉区牙槽骨内活跃的成骨细胞逐渐增加，成骨活性增强；根分叉区牙槽骨内FOXO1主要表达于成骨细胞内，且随着成骨细胞的增加，FOXO1的表达逐渐增强。结论 正畸力介导了根分叉区牙槽骨的改建，FOXO1的表达改变可能与正畸牙移动骨改建相关。

Objective To study the remodeling of alveolar bone and change in expression of forkhead box O1 (FOXO1) during orthodontic tooth movement (OTM) in rat, so as to preliminarily investigate the role of FOXO1 in alveolar bone remodeling induced by orthodontic force. Methods The rat OTM models were established and the left maxillary 1st molars were moved with force of 50 g. The rats were executed on the 1st, 3rd and 7th day of OTM, respectively. HE staining and immunohistochemical staining were used to observe the remodeling of alveolar bone in the inter-radicular region of the 1st molars and expression of FOXO1 at different time points during OTM. Results The 1st molars were constantly moved mesially under orthodontic force. There were more osteoclasts in the alveolar bone of OTM group than that in non-OTM group, and the osteoclasts on the 3rd day of OTM showed the highest activity. The number of active osteoblasts gradually increased in the inter-radicular region of alveolar bone under orthodontic force, with the enhanced osteoblast activity. Expression of FOXO1 in OTM group was elevated compared with non-OTM group. Most osteoblasts in alveolar bone during OTM were FOXO1 positive, and the expression of FOXO1 was gradually increased with the number of osteoblasts increasing. Conclusions Orthodontic force induces bone remodeling of alveolar bone in the inter-radicular region during OTM, and the change in FOXO1 expression may be related to alveolar bone remodeling during OTM.

国家自然科学基金项目(81371121，11342005，30901698，10972142，81570950)，上海市科委资助项目（13ZR1423700，12JC1405700)，上海交通大学“医工交叉基金”（YG2012MS40)，SMC-晨星青年学者奖励计划优秀青年教师（B类计划），上海高校高峰高原学科建设项目