中文摘要：

目的：研究成骨特异转录因子Runx2在去势大鼠正畸牙移动过程中牙周组织内的表达规律。方法：选用3月龄雌性未孕SD大鼠50只，随机分为去势组（OVX）与假手术组（Sham）各25只。全麻下行大鼠去势术或假手术，术后饲养3个月。构建大鼠上颌第一磨牙正畸牙移动模型，并分别于牙移动0d、1d、3d、7d与15d处死去势组大鼠和假手术组大鼠各5只，取上颌第一磨牙周围牙周组织，行H-E染色和免疫组织化学染色后观察正畸牙移动牙周组织的改建。结果：去势大鼠与假手术大鼠正畸牙移动过程中牙周组织的改建基本相似，即张力区以成骨为主，压力区以破骨为主。去势组大鼠牙移动15d张力区成骨细胞及压力区破骨细胞均显著多于假手术组大鼠（尸〈0．05）。大鼠正畸牙移动过程中牙周组织Runx2表达先升后降。牙移动1d、3d、7d张力区与压力区Runx2表达均显著高于0d（P〈0．05），15d与0d则无显著差异。去势组大鼠牙移动牙周组织Runx2表达变化与假手术组大鼠基本一致，但是去势组1d压力区和7d张力区Runx2表达均显著高于假手术组大鼠（P〈0．05）。结论：去势大鼠正畸牙移动过程中的牙周组织改建符合正畸牙移动的基本规律，但其牙周组织的改建更为活跃。去势大鼠正畸牙移动牙周组织内Runx2的表达增强，这可能与活跃的牙周组织改建相关，其机制需进一步研究。

英文摘要：

Objective： To study the expression of runt-related transcription factor 2 （Runx2） in the periodontal ligament during orthodontic tooth movement. Methods： 50 three-month-old female Sprague-Dawley rats were randomly assigned to ovariectomy group （OVX） or sham-ovariectomy group （Sham）. OVX rats were subjected to bilateral ovariectomy and sham-ovariectomy was conducted in Sham rats. After 3 month, the upper left first molars were moved by, coil spring in all rats and lasted for 15 days. The maxillary tissue obtained at 0d, ld, 3d, 7d and 15d in both OVX group and Sham group were applied to histological study. Results： The changes in the periodontal ligament of the OVX rats were similar to that in the Sham rats, which meant bone formation in the tension side and bone resorption in the pressure side. But on 15d, there were more osteoblasts in the tension side and more osteoclasts in the pressure side in the OVX rats when compared with that in Sham rats （P〈 0.05）. The expression of Runx2 significantly increased in periodontal ligament on ld, 3d and 7d of orthodontic tooth movement （P 〈 0.05）. Expression of Runx2 in the periodontal ligament during orthodontic tooth movement in OVX rats was similar to that in the Sham rats, but expression of Runx2 in the pressure side on ld and in tension side on 7d in the OVX rats was significantly higher than that in the Sham rats. Conclusion： The periodontal tissue remodeling during orthodontic tooth movement abode by the basic rules of orthodontic tooth movement, but that appeared more active in the ovariectomied rats. The expression of Runx2 in the periodontal tissue increases during orthodontic tooth movement in the ovariectomied rats, and this may be related to the active periodontal tissue remodeling.