rhPTH加速上颌前部截骨术后正畸牙移动中的实验研究

The study of rhPTH accelerating the orthodontic tooth movement after anterior maxillary osteotomyChen Xiaoyan, Tang Zhenglong, Li Yao, Wang Dongxiang, Gao Qiong

摘要:

目的：研究重组人甲状旁腺激素（recombinant human parathyroid hormone, rhPTH）促进上颌前部截骨术后正畸牙移动的可行性及其调控机制。方法:48只兔建立上颌前部截骨术及右侧上颌第一磨牙正畸移动模型，随机分成实验组和对照组。实验组术后隔日皮下注射rhPTH 20 μg/kg；对照组隔日皮下注射等量生理盐水。两组分别于5、7、14及21天测量右侧上颌第一磨牙向近中移动的距离，并取移动牙近中牙周组织行TRAP染色破骨细胞计数、免疫组化和荧光定量PCR检测骨硬化蛋白(Sclerostin，SOST)、骨形态蛋白-2（bone morphogenetic protein-2，BMP-2）的表达及变化。结果：在同一时间段，实验组右上颌第一磨牙移动距离及速度均快于对照组（P<0.05）。实验组右上颌第一磨牙的近中牙周组织中表达的破骨细胞计数明显大于对照组（P<0.05）。免疫组化和荧光定量PCR检测中发现，实验组右上颌第一磨牙近中牙周组织中SOST mRNA及蛋白的表达明显大于对照组（P<0.05）；而实验组BMP-2 mRNA及蛋白的表达则低于对照组（P<0.05）。结论：隔日皮下注射rhPTH可能通过上调正畸牙近中压力侧SOST的表达，下调BMP-2的表达，增加牙槽骨的改建从而加快上颌前部截骨术后正畸牙的移动速度。

Abstract:

Objective:To study the feasibility and regulation mechanism of recombinant human parathyroid hormone(rhPTH) to promote orthodontic tooth movement after maxillary anterior osteotomy. Methods: Forty-eight rabbits were used to a model of anterior maxillary osteotomy and the orthodontical movement of right maxillary first molars. They were randomly divided into experimental group and control group. The group received subcutaneous injection of rhPTH 20 μg/kg or normal saline every other day. On the 5th, 7th, 14th, and 21th days, the animals were sacrificed respectively. Then the mesial movement distance of the right maxillary first molars was measured. The TRAP staining, immunohistochemistry and fluorescence quantitative PCR were performed on the proximal periodontal tissues of the moving tooth. Results: At the same stage, the moving distance and speed of the first molars in the experimental group were faster than those in the control group (P<0.05). In the mesial periodontal tissue of right maxillary first molars, the osteoclast counts of the experimental group was significantly larger than that of the control group (P<0.05). Through immunohistochemistry and fluorescence quantitative PCR Testing, In the mesial periodontal tissue of right maxillary first molars, the expression of Sclerostin (SOST) mRNA and protein in the experimental group was significantly higher than those in the control group (P<0.05), while the bone morphogenetic protein-2(BMP-2) mRNA and protein in the experimental group were lower than that of the control group (P<0.05). Conclusion: In the proximal pressure side of the orthodontic tooth after maxillary anterior osteotomy, subcutaneous injection of rhPTH may increase the alveolar bone remodeling to accelerate the movement speed of orthodontic tooth by up-regulating the expression of SOST and reducing the expression of BMP-2.