【作者】 陈雁南；

【导师】 李晓智；

【作者基本信息】 重庆医科大学 ， 生物医学信息技术， 2012， 博士

【摘要】 牙齿接受正畸治疗时受正畸力产生移动。牙齿移动的过程正是颌骨改建的过程。破骨细胞具有骨吸收功能，成骨细胞具有骨形成功能，骨骼的完整靠这两种细胞功能间的平衡维持。以往的研究证实，多种药物、激素、生长因子及细胞因子参与颌骨改建的调控。OPG/RANKL/RANK系统是调控破骨细胞形成的生理基础，从而调控骨改建。骨保护素(OPG)属于肿瘤坏死因子受体的一种，RANKL属于肿瘤坏死因子受体配体，主要由成骨细胞分泌，它与破骨细胞表面的特异性受体RANK相结合，促进破骨前体细胞分化成熟形成具有骨吸收功能的破骨细胞，OPG与RANK的竞争性结合抑制了RANKL与RANK的结合。骨保护素的主要作用是抑制破骨细胞生成、活化，在牙槽骨抑制颌骨的吸收，维持颌骨的完整。二磷酸盐是一种人工合成的焦磷酸盐类似物，具有显著抑制羟基磷酸钙结晶溶解的特性,能显著抑制骨溶解。正畸医师所面临的治疗难点就是支抗牙移动的控制。传统增强支抗的方法均是通过增强机械力的方式，其效果依赖于患者的配合。而近年来应用广泛的微种植体支抗具有提供持续稳定的高强度支抗的优点，但其植入和取出均需外科手术，且费用较高。如果能够应用药理机制和牙齿移动的机制来控制破骨细胞的产生从而控制牙槽骨的吸收，就可以达到控制牙齿移动的目的，且不需患者配合，更不需外科手术。本文建立大鼠正畸牙移动实验模型，主要研究：（1）局部注射不同浓度的OPG比较不同浓度的OPG对大鼠正畸牙移动距离的影响、牙周组织形态的变化及破骨细胞数量的影响。（2）局部注射阿仑磷酸钠研究其对大鼠正畸牙移动距离的影响、牙周组织形态的变化及破骨细胞数量的影响。（3）比较局部注射不同浓度OPG与阿仑磷酸钠对鼠正畸牙移动、牙周组织形态、破骨细胞数量的影响的差别。实验中选用10周龄雄性SD（Spargue-Dewley）大鼠100只，体重250g-300g。按照局部注射药物与浓度随机分为0.5mg/kg OPG组、0.2mg/kg OPG组、0.05mg/kg OPG组、0.05mg/kg阿伦磷酸钠组、生理盐水组。安置于右侧上颌切牙和上颌第一磨牙间的镍-钛拉簧产生40g的牵引力，牵引上颌第一磨牙近中移动。按照局部注射剂量，将OPG、阿仑膦酸钠、生理盐水注射于大鼠右侧第一磨牙粘骨膜下靠近根分叉处。在注射药物后1d、4d、7d、14d，每组分别处死5只大鼠，测量右侧上颌第一磨牙近中移动的距离，取含右侧上颌第一磨牙的上颌骨块进行切片，行HE染色和TRAP免疫组化染色，观察牙周组织形态变化、计数破骨细胞数量。实验得出以下结果：1.7d和14d时，牙齿移动量：0.5mg/kg OPG组<0.2mg/kg OPG组<0.05mg/kg OPG组<0.05mg/kg阿伦磷酸钠组<生理盐水组，有显著性差异（p<0.05）。2．切片HE染色观察，7d和14d时，生理盐水组压力侧能观察到显著的牙槽骨吸收，0.5mg/kg OPG组、0.2mg/kg OPG组、0.05mg/kg OPG组和0.05mg/kg阿伦磷酸钠组压力侧牙槽骨吸收不明显。3.切片TRAP染色发现，4d和7d时，第一磨牙近中根压力侧破骨细胞数量0.5mg/kg OPG组<0.2mg/kg OPG组<0.05mg/kg OPG组<0.05mg/kg阿伦磷酸钠组<生理盐水组（p<0.05）。14d时，破骨细胞数量0.5mg/kgOPG组<0.2mg/kg OPG组<0.05mg/kg OPG组<生理盐水组（p<0.05），而0.05mg/kg阿仑磷酸钠组的破骨细胞数量和生理盐水组比较无显著差异（p>0.05）。更多还原

【Abstract】 During orthodontic treatment,teeth is moved by orthodontic force. Theprocess of tooth movement is the process of jaw conversion. The dynamicbalance between osteoclast resorption and osteoblast bone formation andtheir coupling maintains the integrity of the bone. The previous studyconfirmed that a variety of drugs,hormones,growth factors and cytokinesinvolved in the regulation of jaw alterations. OPG/RANKL/RANKsystem is a physiological basis for the regulation of osteoclast formation,and thus the regulation of bone remodeling. Osteoprotegerin (OPG) is atumor necrosis factor receptor; RANKL is a tumor necrosis factor receptorligand, mainly secreted by osteoblasts.RANKL combines with osteoclastsurface specific receptor RANK to promote breaking differentiation andmaturation of precursor cells in the bone formation with bone resorptionfunction of osteoclasts. OPG competitively combines with RANK toprevent the combination of RANKL and RANK.The primary role of OPG is to inhibit osteoclastogenesis, activation, thusinhibiting the absorption of the jaw to maintain the integrity of the jaw. Thediphosphate is a synthetic analogue of pyrophosphate, a significantinhibition of hydroxyapatite crystallization of dissolved properties, and it is able to significantly inhibit osteolysis. In Orthodontic treatment, it isdifficult for orthodontic physicians to control the anchorage toothmovement. The traditional method to enhance the anchorage is to enhancethe mechanical force and its effect depends on the patients’cooperation.Application of a wide range of micro-implant anchorage in recent years hasthe advantage of steadily high strength anchorage, but the implants andremoval require surgery, and costs are high.To apply the pharmacologicalmechanisms and the mechanism of tooth movement in order to control thegeneration of osteoclasts and thus to control the absorption of alveolar bone,we would be able to achieve the purpose of tooth movement control,without patients’ cooperation and without surgery.In this study, anchorage tooth movement during orthodontic treatment issimulated through the establishment of animal models.It covers:(1).Localinjection of different concentrations of OPG to compare the differentconcentrations of OPG distance of orthodontic tooth movement in rats, themorphological changes of the periodontal tissues and the number ofosteoclasts.(2). Local injection of alendronate to study the impact ondistance of orthodontic tooth movement in rats, the morphological changesof periodontal tissue and the number of osteoclasts.(3). Comparison theimpact of local injection of different concentrations of OPG andalendronate on the distance of orthodontic tooth movement, periodontaltissue morphology, the number of osteoclasts. The study chooses100 10-week-old male SD (Spargue-Dewley) rats, weight at250g-300g. Inaccordance with local injection and the concentration, rats are randomlydivided into0.5mg/kg OPG group,0.2mg/kg OPG group,0.05mg/kg OPGGroup,0.05mg/kg alendronate group,saline group. Placed between the rightmaxillary incisors and maxillary first molar nickel-titanium extensionspring, extension spring opened to produce40g force, and traction of themaxillary first molar mesial movement. In accordance with local injectiondose,OPG,alendronate and saline was injected into the right first molarperiosteum near the root of the bifurcation. After injection,1d,4d,7d,14d,5rats of each group were sacrificed, measuring the distance of the firstmolar movement, take with the first molars of the experimental side, themaxillary bone slices, HE staining and TRAP immunohistochemicalstaining to observe the changes in morphology, the osteoclastcount.Experiment obtained the following results:1.7d and14d, the amount of tooth movement:0.5mg/kg OPG group<0.2mg/kg OPG group<0.05mg/kg OPG group<0.05mg/kg alendronategroup <saline group,with a significant difference (p <0.05).2. HE staining observation, pressure side in0.05mg/kg saline group can beobserved significant alveolar bone absorption, alveolar bone resorptionof pressure side in0.5mg/kg OPG group,0.2mg/kg OPG group,0.05mg/kg OPG group and0.05mg/kg alendronate group is not obvious.3. Slice TRAP staining,4d and7d, number of osteoclasts in the first molar root pressure side:0.5mg/kg OPG group0.2mg/kg OPGgroup<0.05mg/kg OPG group<0.05mg/kg alendronate group <salinegroup (p <0.05).14d,0.5mg/kg OPG group <0.2mg/kg OPGgroup<0.05mg/kg OPG group <saline group(p<0.05),0.05mg/kg OPGgroup and0.05mg/kg alendronate group have no significant differences(p>0.05).更多还原