实验性牙移动过程中三叉神经节内神经生长因子受体TrkA的改变

目的观察实验性牙移动时,神经生长因子受体TrkA在三叉神经节内的改变。方法采用免疫荧光方法观察大鼠实验性牙移动后,三叉神经节内TrkA免疫阳性细胞的改变。结果实验性牙移动加力24 h组3、d组、1周组,实验侧三叉神经节内TrkA免疫阳性神经元较对侧增多;2周组实验侧三叉神经节TrkA免疫阳性神经元与对照组相比差异无显著性。结论实验性牙移动时,实验侧三叉神经节内TrkA免疫阳性神经元增多。     

大鼠正畸牙移动过程中TRPV1和CGRP在三叉神经节中的表达变化

目的建立SD大鼠正畸牙移动模型,研究牙移动过程中,三叉神经节(trigeminal ganglion,TG)中瞬时受体电位香草酸亚型1（transient receptor potential vanilloid 1,TRPV1）及降钙素基因相关肽(calcitonin gene related peptide,CGRP)的表达位置及表达量的变化规律,进而探讨其在正畸疼痛中的作用机制。方法将66只SD大鼠随机分为空白对照组（6只）、假手术组（6只）和实验组（54只）。建立正畸牙移动模型,实验组大鼠施加50 g力后,分别于4、8 h、1 d（1 d组按力值大小分为1 d-30 g、1 d-50 g、1 d-80 g 3个亚组）、3、5、7、14 d,随机处死6只,切取三叉神经节,采用免疫荧光技术分别检测大鼠三叉神经节中TRPV1及CGRP的表达位置及表达量变化。采用SPSS16.0软件包对数据进行统计学分析。结果免疫荧光染色显示,TRPV1及CGRP主要表达于小型及中型神经元。随着加力时间的延长,三叉神经节中TRPV1免疫反应阳性（TRPV1-IR）神经元百分比及CGRP免疫反应阳性（CGRP-IR）神经元百分比增加,1~3 d相继达到高峰,之后逐渐降低,回落至初始水平,且两者随加力力值增大而呈现增高趋势。结论大鼠正畸牙移动过程中,三叉神经节内TRPV1及CGRP的表达随加力时间及加力力值改变呈现规律性变化,提示TRPV1及CGRP可能在正畸疼痛的发生机制中具有重要作用。     

正畸力作用下大鼠牙周组织中骨桥蛋白的表达

目的：观察SD大鼠正畸牙齿移动过程中牙周组织内骨桥蛋白（osteopontin,OPN）的表达,探讨OPN在正畸牙齿移动过程及成骨方面的作用和机制。方法：选用6～8周龄雄性SD大鼠40只,以左侧上颌第一磨牙为实验组,右侧上颌第一磨牙不加力为对照组,通过自制的加力装置牵引移动大鼠的磨牙,分别在加力后8h、24h、3d、7d处死实验动物,即刻取上颌骨制备组织标本,通过免疫组织化学方法检测SD大鼠牙周组织中OPN的表达。结果：实验组大鼠牙周膜中张力侧OPN表达明显高于对照组,3d、7d组差异有统计学意义（P〈0.01）。结论：在正畸治疗牙齿移动过程中,OPN参与牙周组织的改建并与新骨的形成相关。     

局部注射重组人转化生长因子对大鼠正畸牙移动的影响

目的:探讨局部注射重组人转化生长因子 (rhTGF -β1)对大鼠正畸牙移动速度的影响。方法:80只模型大鼠随机分为实验组和对照组,每组又按1、4、7、10和14 d再分为5个小组,每小组8只。实验组从加力的第1天开始,每2 d在大鼠加力侧上颌第一磨牙颊侧黏膜下注射rhTGF-β1 0.1 mL(5 ng/mL),对照组注射相同容量的PBS。加力后依实验设计时间分别处死每1小组大鼠。体视显微镜观察并采集图像,运用计算机图像分析软件测量牙移动的距离,同时应用TRAP组织化学染色观察不同时段压力侧破骨细胞数量的变化,采用SPSS 17.0 软件包对数据进行统计学分析。结果:局部注射rhTGF-β1的牙移动速度较对照组快,在加力后第7天,牙移动距离差异显著(P<0.05);第10天和第14天相比,差异显著(P<0.01)。实验组压力侧破骨细胞的TRAP阳性细胞数较对照组显著增多(P<0.01)。结论:局部注射rhTGF-β1增强了大鼠正畸牙破骨细胞的活性,促进了破骨细胞的骨吸收功能,加速了正畸牙移动。     

大鼠正畸牙移动过程中牙周组织NGF的表达变化

目的了解大鼠正畸牙移动过程中牙周组织内神经生长因子(nerve growth factor,NGF)的变化,探讨NGF在正畸牙移动过程中的作用。方法将85只雄性SD大鼠随机分为17组,其中空白对照组(0d组)、实验加力和对照不加力组各6h、12h、24h、3d、5d、7d、14d、21d组。选择左上第一磨牙作为实验牙,制备大鼠正畸牙移动不同时间牙周组织切片,进行免疫组织化学研究。结果正畸牙移动过程中,牙周组织内NGF表达发生改变。NGF表达量在正畸模型加载后迅速上调,实验组和对照组分别于5d、1d时表达水平达到最高,所有观察区域牙周膜内NGF表达显著增加,且实验组明显高于对照组。结论NGF在正畸牙移动过程中牙周组织改建的多个阶段起作用,参与了牙周膜早期的炎症反应及修复和晚期的改建。     

rhPDGF-BB与rhTGF-β1联合应用对大鼠正畸牙压力侧破骨细胞FAK mRNA表达的影响

目的：观察外源性的血小板衍生生长因子-BB （rhPDGF-BB）与转化生长因子-β1（rhTGF-β1）联合应用对大鼠正畸牙压力侧破骨细胞FAK mRNA 基因水平的表达变化。方法：将160只SD大鼠随机分为实验组和对照组。每组又根据检测时间点不同分为5个小组（n＝16）,分别建立正畸牙移动模型。实验组从加力第1天开始在正畸牙颊侧黏膜下隔日注射rhP-DGF-BB 10 ng与rhTGF-β15 ng,对照组注射相同容量的PBS。加力后1、4、7、10和14 d分别处死每大组的一小组大鼠。收集标本,用TRAP染色观察压力侧破骨细胞数量的变化,实时定量PCR（RT-PCR）检测FAK mRNA基因的表达。结果：rhP-DGF-BB及rhTGF-β1联合注射明显促进压力侧破骨细胞数目的增加（P＜0．05）;破骨细胞内FAK mRNA基因量的表达7 d前增加（P＜0．05）,7 d后逐渐降低,14 d时与对照组无显著差异（P＞0．05）。结论：外源性PDGF-BB和TGF-β1联合应用促进正畸牙压力侧破骨细胞增殖,增加了破骨细胞内FAK mRNA基因表达。     

重组人血小板衍生生长因子-BB对大鼠正畸牙移动过程中破骨细胞内黏着斑激酶表达的影响

目的观察血小板衍生生长因子-BB（plateletderived growth faetor-BB,PDGF—BB）对大鼠正畸牙移动过程中破骨细胞内黏着斑激酶（focal adhesion kinase,FAK）表达的影响,探讨PDGF-BB对正畸牙移动骨改建中破骨细胞的作用及其下游信号通路。方法80只sn雄性大鼠上颌安装施加50g力的正畸装置,牵引上颌第一磨牙近中移动,隔日于正畸牙局部黏膜注射10ng的重组人血小板衍生生长因子-BB（recombinant human ptatelet derived growth factor-BB,rhPDGF-BB）,对照组注射磷酸盐缓冲液,在加力后1,4、7、10、14d处死动物,制备标本并测量牙齿移动距离,抗酒石酸酸性磷酸酶计数压力侧破骨细胞数量,免疫组织化学方法观察破骨细胞内FAK表达变化。结果PDGF-BB明显促进压力侧破骨细胞增殖,加速正畸牙移动,除第1天实验组与对照组牙移动距离差异无统计学意义以外,其余均有统计学意义（p〈0．05）;各观察点实验组破骨细胞FAK表达均高于对照组,灰度值比较差异均有统计学意义（p〈0.05）。结论外源性的PDGF—BB影响正畸牙移动骨改建过程。在大鼠正畸牙压力侧牙槽骨改建的过程中,FAK参与了破骨细胞信号转导的下游通路,其表达能被外源性的rhPDGF-BB所调节。     

辛伐他汀对牙周炎大鼠牙移动保持阶段OPG表达影响的实验研究

目的：观察牙周炎大鼠正畸性牙齿移动保持阶段,全身给予辛伐他汀对牙周组织中OPG表达的影响。方法：选用雄性Wistar大鼠65只,随机分组。1）空白对照组：不做任何处置。2）阴性对照组和实验组：根据Fishcer等人的方法,在大鼠上颌第一磨牙牙颈部用3～0丝线龈缘水平进行结扎,28d后诱导形成大鼠牙周炎,牵引其上颌第一磨牙向近中移动。实验组在加力装置去除前1d开始,腹膜下注射辛伐他汀,阴性对照组注射生理盐水,1次/d,分别保持1、3、7、14、21、28d后处死,免疫组化染色配合定量分析方法观察上颌第一磨牙牙根的近远中侧OPG的表达变化。结果：移动牙近中牙周组织OPG的表达在加力结束后逐渐减少,第7天时阴性对照组低于空白对照组,14d后两组均有少量增加;远中侧阴性对照组OPG的表达在加力结束后1、3d变化不明显,而实验组OPG的表达逐渐增加,但在21d后变化不明显。相同时间段比较,实验组OPG表达量均高于阴性对照组。结论：辛伐他汀能够增加牙周炎大鼠正畸牙移动后牙周组织中OPG的表达量。     

M-CSF油包水型微乳对大鼠正畸牙齿移动的影响

目的探讨巨噬细胞集落刺激因子（M—CSF）油包水型（W／O）微乳对大鼠正畸牙齿移动及其牙周组织改建的影响。方法选用蓖麻油和无水乙醇分别作为表面活性剂和助表面活性剂,油酸聚乙二醇甘油酯作为油相,M-CSF水溶液为水相,制备成M—CSF油包水型微乳。加力ld开始,每2d将该微乳局部注射于大鼠左上第一磨牙,分别于1d,3d,7d,14d测量上颌第一磨牙移动距离,用HE染色观察牙周组织改建情况。结果加力1d,4组间无明显差异（P〉0．05）;加力3d,M—CSF微乳组正畸牙移动距离大于其它组,但与M—CSF水溶液组差别无统计学意义（P〉0．05）;加力7d和14d,M-CSF微乳组正畸牙移动距离同样大于其它组,差异有统计学意义（P〈0．01）,且压力侧牙槽骨骨吸收陷窝增多,呈“锯齿”状。结论大鼠正畸牙齿局部注射M．CSF油包水型微乳可以促进其移动及压力侧牙周组织改建。     

Increase of galanin in trigeminal ganglion during tooth movement

It is known that nerve fibers containing neuropeptides such as galanin increase in the periodontal ligament during experimental tooth movement. However, the origin of galanin-containing nerve fibers in the periodontal ligament remains unclear. This study was conducted to examine our hypothesis that the increased galanin nerve fibers have a sensory neuronal origin, and that the peptide is associated with pain transmission and/or periodontal ligament remodeling during experimental tooth movement. In control rats, galanin-immunoreactive trigeminal ganglion cells were very rare and were observed predominantly in small ganglion cells. After 3 days of experimental tooth movement, galanin-immunoreactive trigeminal ganglion cells significantly increased, and the most marked increase was observed at 5 days after experimental tooth movement. Furthermore, their cell size spectrum also significantly changed after 3 and 5 days of movement: Medium-sized and large trigeminal ganglion cells began expressing, and continued to express, galanin until 14 days after experimental tooth movement. These findings suggest that the increase of galanin in the periodontal ligament during experimental tooth movement at least partially originates from trigeminal ganglion neurons and may play a role in pain transmission and/or periodontal remodeling.     

Effects of gradually increasing force generated by permanent rare earth magnets for orthodontic tooth movement

OBJECTIVE: To examine the effects of gradually increasing force generated by permanent rare earth magnets for orthodontic tooth movement by using a novel experimental rat model and computer simulation. MATERIALS AND METHODS: Fifty-five male rats (age 18 weeks) were used as animal experiments. Magnetic (experimental groups) or titanium (control group) cuboids (1.5 x 1.5 x 0.7 mm) were bonded to the lingual surface of the maxillary first molars. The initial distance between materials was 1.0 mm, generating 4.96 gf (experimental group I), or 1.5 mm, generating 2.26 gf (experimental group II). Tooth movement was measured and periodontal structures were observed with microfocus x-ray computed tomography radiographs. RESULTS: The distance between the magnets decreased with time in experimental groups I and II (P < .001), whereas there was no tooth displacement in the control group. Experimental group I showed rapid tooth movement in the initial phase followed by slower tooth movement. Experimental group II showed gradual tooth movement. Horizontal sections on microfocus computed tomgraphy radiographs revealed no pathological changes, such as root resorption, on the compressed side in the experimental groups. CONCLUSIONS: The initial light force and gradual increasing force in magnetic attractive force induced effective tooth movement in rats without inducing any pathological changes.     

釉基质蛋白衍生物对大鼠牙移动后复发和牙根修复的影响

目的:观察釉基质蛋白衍生物对大鼠正畸牙移动后早期复发和牙根吸收的影响.方法:选用20只10周龄雄性SD大鼠,实验组和对照组各10只,在左上第一磨牙施加100 g力,使其近中移动,加力14d后拆除装置.自拆除加力装置起,实验组局部注射釉基质蛋白衍生物,对照组不注射任何药物.分别于拆除装置后当天及第14天分别行Micro-CT活体扫描,分析牙根吸收陷窝以及牙移动距离的变化.采用SPSS19.0软件包对数据进行统计学分析.结果:拆除装置14 d后,实验组与对照组牙根吸收陷窝体积修复量分别为(0.0295±0.0052) ×1 07 μm3、(0.0189±0.0086)×107 μm3;牙移动后复发距离及复发百分率分别为(0.089±0.005)mm、(64.76±3.63)％和(0.127±0.010)mm、(92.28±1.90)％.统计学分析表明,拆除装置14 d后,牙根吸收陷窝体积修复量、牙移动后复发距离及复发百分率均有显著差异(P＜0.05).结论:一定浓度的釉基质蛋白衍生物可在一定程度上加强大鼠正畸移动后牙根吸收后修复效应,减弱牙移动后早期复发.     

Compensatory bone formation in young and old rats during tooth movement

The aim of this study was to investigate compensatory lingual alveolar bone formation during tooth movement in young and old rats, using the vital bone marker tetracycline. Wistar male rats were separated into the following groups: 13-week-old rats without appliances (13C: control, n = 5), 60-week-old rats without appliances (60C: control, n = 5), 13-week-old rats with appliances (13E: experimental, n = 10), and 60-week-old rats with appliances (60E: experimental, n = 10). The upper first molars of the 13E and 60E groups were moved lingually using fixed appliances. On the third day of tooth movement, tetracycline (TC) was intra-peritoneally injected in all animals including the controls. On the 21st day of tooth movement, the animals were killed and unfixed, and undecalcified, 5-microm frozen frontal sections of the rat first molar areas in both control and experimental groups were examined under light and fluorescent microscopes. In the 13C group without tooth movement, tetracycline labelling lines were obvious in the alveolar crest, apical areas, and interradicular septum, indicating vertical alveolar bone growth. However, in the 60C control group, tetracycline labelling was almost undetectable throughout the alveolar bone. Although the lingual alveolar crest was resorbed from the periodontal side after lingual tooth movement, the sharp, bright labelling lines were still present from the crest to the lingual periosteal alveolar bone in the 13E group. In the 60E group the lines appeared in the lingual periosteal alveolar bone containing the crest, indicating considerable new bone formation. The results indicate that compensatory bone formation occurs in the alveolar crest area and, consequently, alveolar bone height is maintained, even in aged rats.     

超声波加速正畸牙移动的实验动物研究

目的:在大鼠正畸模型中,对第一磨牙牙周组织施加超声波振动,观察超声波是否能加速正畸牙移动。方法:选用30只SD大鼠,建立以中切牙为支抗,移动单侧第一磨牙的正畸模型,分为常规正畸组和超声波振动组。于加力第7、14、28天测量牙移动距离,HE染色,trap染色破骨细胞计数,Masson染色观察第一磨牙牙周组织的变化。结果:牙周组织接受超声波振动刺激后,大鼠第一磨牙在第7、14、28天移动速率显著高于常规正畸组(P<0.05);同时可观察到超声波振动组中TRAP阳性的破骨细胞显著多于常规正畸组(P<0.05)。而Masson染色则显示,在加力第7天,常规正畸组和超声波振动组中,皆出现新生骨;但第14天时,前者新骨形成更加明显;直到第28天超声波后者出现更大规模的成骨反应。结论:超声波显著、并持续地增加牙周组织内破骨细胞形成数量,此效应可能导致了大鼠正畸模型的牙齿移动的加速,成功建立超声波加速正畸牙移动的实验动物模型。     

骨皮质切开术辅助大鼠正畸牙移动中OPNmRNA、BSPmRNA、OCNmRNA表达的研究

目的:观察骨桥蛋白(OPN),骨涎蛋白(BSP),骨钙蛋白(OCN)在大鼠骨皮质切开术辅助正畸牙移动过程中的表达情况。方法:选取健康雄性Wistar大鼠65只,60只大鼠随机分成3组:组Ⅰ:选择性骨皮质切开术;组Ⅱ:传统的牙齿移动;组Ⅲ:混合组,剩余5只作为空白对照组(不作任何处理)。用镍钛螺旋拉簧施加约60 g力近中移动上颌实验侧第一磨牙,在第一磨牙颊腭侧行骨皮质打孔术式,分别在加载第7、14、21、28、42天颈椎脱臼处死取材,进行SYBR Green实时荧光定量PCR技术,对Ct值进行分析。结果:混合组中的成骨细胞相关细胞因子:OPN(骨桥蛋白),Bone sialoprotein(BSP骨涎蛋白),Osteocalcin(OCN骨钙蛋白)的表达早期增加暗示了同化合成反应的增加。结论:正畸牙齿移动初期骨皮质切开术加速了牙齿移动,改变了早期骨代谢状态,成骨活跃,支持区域性骨代谢加速学说。     

The effect of pregnancy on orthodontic tooth movement in rats

Introduction: The purpose of this study was to investigate the effect of pregnancy on orthodontic tooth movement in Wistar rats. Material and Methods: Forty eight female three-month old Wistar rats with an average weight of 250±25 gr were selected and randomly divided into two experimental (pregnant) and control groups (non-pregnant). Maxillary central incisors were tipped distally by insertion of springs exerting 30g force. Two, seven and fourteen days after spring insertion animals were sacrificed. Then the mesioincisal distance between maxillary incisors were measured. Subsequently, histological sections were prepared to count osteoclasts under a light microscope. The data on the extent of orthodontic tooth movement, and the number of osteoclasts were analyzed by independent sample t-test. Results: The results indicated that 2,7 and 14 days after force application there was no significant difference in orthodontic tooth movement between experimental and control groups (p>0.05). The number of osteoclasts were significantly lower in the experimental group 7 and 14 days after spring insertion (p<0.05). Conclusion: Pregnancy may decrease the amount of tooth movement in the linear phase but it is not statistically significant. The number of osteoclasts is significantly decreased during pregnancy. Key words:Pregnancy, rat, orthodontic tooth movement, osteoclast.     

The effect of oral contraceptives on orthodontic tooth movement in rat

Introduction: The purpose of this study was to investigate the effect of ethinyl estradiol/norgestrel � used in some oral contraceptives- on orthodontic tooth movement in Wistar rats. Material and Methods: Forty eight female three-month old Wistar rats with an average weight of 250�25gr were divided into two experimental and control groups. One week prior to appliance insertion and during the appliance therapy period, 100 mcg/kg/day of ethinyl estradiol and 1mg/kg/days of norgestrel were administered to the experimental group by gavage; meanwhile the control group received an equivalent volume of Sodium Chloride 0.9 % (Saline). Maxillary central incisors were tipped distally by insertion of springs exerting 30g force. Two, seven and fourteen days after spring insertion animals were sacrificed. The mesioincisal distance between maxillary incisors were measured. Subsequently, histological sections were prepared for histomorphometric studies. Results: 14 days after force application the orthodontic tooth movement was significantly lower in the experimental group (p<0.05). The number of osteoclasts were significantly lower in the experimental group 2, 7 and 14 days after spring insertion (p<0.05). Conclusion: Ethinyl estradiol/norgestrel (oral contraceptives) can significantly decrease the amount of tooth movement in the linear phase. Key words:Oral contraceptives, orthodontic tooth movement, ethinyl estradiol, norgestrel.     

Galanin-immunoreactive nerve fibers in the periodontal ligament during experimental tooth movement

Neuropeptides have been suggested to play a role in pain transmission during orthodontic tooth movement. We examined this hypothesis by examining the effect of orthodontic tooth movement on the expression of galanin (GAL)-immunoreactive (ir) nerve fibers in the periodontal ligament (PDL) of one mesial root (MR) and two distal roots (DRs) of the rat maxillary first molar. In control rats, GAL-ir fibers were very rare in the PDL. One day after the insertion of the elastic band, the number of GAL-ir fibers increased, becoming most numerous at 3 days. From 5 to 28 days, GAL-ir fibers tended to decrease. Electron microscopic observation showed that all of the GAL-ir fibers were unmyelinated. These findings suggest that GAL-containing nerve fibers in the PDL may play an important role in the response of the tissue to experimental tooth movement.     

大鼠正畸牙移动中NF-κB通路相关差异基因的GO分析

目的:利用基因表达谱芯片对正畸加力组与正常大鼠牙齿牙周组织的基因表达谱进行对比分析,筛选差异基因并进行GO分析。方法:将6只SD大鼠随机分为加力组和对照组,加力组建立大鼠正畸牙齿移动模型。根据预实验结果,分别在0 h、12 h处死大鼠,并截取上颌第一磨牙及外周约1 mm的牙周组织,提取总RNA,进行全基因组表达谱芯片检测,对差异表达基因进行GO分析,并运用RT-qPCR对芯片结果进行验证。结果:芯片结果显示,共筛选到463条差异基因,其中实验组与对照组相比250个基因表达上调,213个基因表达下调,在差异基因中涉及到NF-κB信号通路的基因有8个,均表达上调。GO分析涉及到1189个不同的功能分类。结论:正畸加力12h后牙齿牙周组织中与炎症反应相关的基因和与中性粒细胞趋化相关的基因表达上调。