rhPTH加速上颌前部截骨术后正畸牙移动中的实验研究

Study of recombinant human parathyroid hormone to accelerate orthodontic tooth movement after anterior maxillary osteotomy

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 20μg/kg;对照组隔日皮下注射等量生理盐水。2组分别于第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抗酒石酸酸性磷酸酶(tartrate resistant acid phosphatase,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(fluorescence quantitative polymerase chain reaction,qPCR)检测发现,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。

Objective:To study the feasibility and regulation mechanism of recombinant human parathyroid hormone(rhPTH)for promoting orthodontic tooth movement after the maxillary anterior osteotomy.Methods:Forty-eight rabbits were used to establish the model of anterior maxillary osteotomy and orthodontical movement of right maxillary first molars.They were randomly divided into the experimental group and the control group.The experimental group received subcutaneous injection of rhPTH 20μg/kg,while the control group received the normal saline every other day.The mesial movement distance of the right maxillary first molars was measured on the 5th,7th,14th and 21th day.The mesio-periodontium of moving teeth were taken and tartrate resistant acid phosphatase(TRAP)staining of osteoclast count,immunohistochemistry and fluorescence quantitative polymerase chain reaction(qPCR)of sclerostin(SOST)and bone morphogenetic protein-2(BMP-2)were performed.Results:During the same period,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 count in the experimental group was significantly larger than that in the control group(P<0.05).According to the immunohistochemistry and qPCR,the expression of SOST mRNA and protein of the mesial periodontal tissue of right maxillary first molars in the experimental group was significantly higher than that in the control group(P<0.05),while the expression of BMP-2 mRNA and protein in the experimental group was lower than that in the control group(P<0.05).Conclusion:In the proximal pressure side of the orthodontic tooth after maxillary anterior osteotomy,subcutaneous injection of rhPTH on every other day may increase the alveolar bone remodeling to accelerate the movement speed of orthodontic tooth by upregulating the expression of SOST,downregulating the expression of BMP-2 and increasing the reconstruction of alveolar bone.