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。     

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.     

骨皮质切开术对大鼠牙移动影响的实验研究

目的建立骨皮质切开术正畸牙移动实验动物模型,观察移动速率和对牙周组织改建的影响。方法 75只SD大鼠,实验组35只行上颌双侧中切牙骨皮质切开术,1周后与对照组35只同时进行正畸加力,空白对照组5只不进行加力。按不同加力时间处死,测量牙齿移动的距离,观察组织学改变。结果实验组2周时牙齿移动距离(3.471±0.359)mm,对照组为(1.247±0.198)mm,具有显著性差异;HE染色结果表明,实验组牙周膜内玻璃样变组织的形成相对于对照组来说,范围缩小,时间缩短。结论骨皮质切开术能够加速正畸牙移动。     

大鼠实验性牙移动过程中三叉神经节内甘丙肽表达的研究

目的：研究实验性牙移动过程中大鼠三叉神经节内甘丙肽表达的变化,探讨其与正畸疼痛缓解之间是否具有内在的联系。方法：选择雄性Wistar大鼠35只,建立正畸牙移动动物模型,将大鼠随机分为实验组与空白对照组。实验组左侧为加力侧,右侧为未加力侧,左右自身对照,分别于加力6h、12h、1、3、5、7d后处死动物,取大鼠三叉神经节,标本制备,进行免疫组织化学染色与图像分析。采用SPSSl6．0统计学软件进行统计学分析。结果：与空白对照组相比,实验组加力1d甘丙肽阳性细胞数增多,表达增强（P〈O．05）;加力3d阳性细胞数增多明显（P〈O．01）;加力5d甘丙肽免疫阳性细胞数达到高峰,神经节细胞中甘丙肽免疫阳性染色呈强阳性表达（P〈0．01）。实验组未加力侧各时间点与空白对照组之间甘丙肽表达无统计学差异。结论：GAL作为内源性镇痛物质与正畸牙移动所致牙体与牙周疼痛的缓解具有一定的内在联系。     

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。     

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.     

Evening primrose oil effects on osteoclasts during tooth movement

This study was conducted to investigate the influence of supplemented evening primrose oil (EPO) on osteoclast expression during experimental tooth movement in rats. Forty-eight 10-week-old male Sprague-Dawley rats were divided into experimental and control groups. Animals in the experiment group were fed a 7.25 g/kg daily dose of EPO orally by gastric intubation for 20 days before orthodontic tooth movement. The animals in the control group received an equivalent volume of distilled water by the same method. On day 21, a 40-g mesial tipping force was applied to the maxillary right first molar of each rat. After loading, six animals in each group were sacrificed on days 0, 3, 7, and 14 with the appliance in situ. On day 3, the number of osteoclasts on the appliance side of the experimental group was significantly increased compared with the control group (P < .05). On day 7, the number of osteoclasts on the non-appliance side of the experimental group was significantly increased compared with the control group (P < .05). This study indicates that oral administration of EPO can increase the number of osteoclasts and may accelerate orthodontic tooth movement.     

Long-term orthodontic tooth movement response to short-term force in the rat.

Both the amount of force applied and the duration of the application affect tooth movement. To study the effect of duration, adult male Sprague-Dawley rats were fitted with orthodontic appliances delivering a 40-gm initial mesial tipping force to the maxillary molars. The animals were divided into two longitudinal groups (I: 1 hour and II: 24 hours; N = 15). Sham-treated control (III) and 14 day (IV) continuous cross-sectional force tooth movement data were also included for comparison (72 rats per group). Extraoral cephalometric radiographs were obtained at appliance placement and at 1, 3, 5, 7, 10, & 14 days. Tooth movement was determined with respect to palatal implants. ANOVA indicated significant differences existed over time in each group (p = 0.0001). Continuous force applied for 14 days generated a classic three-part tooth movement curve. Short-term forces were characterized by initial mesial movement, a distal relapse period (d3-d5), and a late mesial movement period (d7-d14). The results suggest short-term forces of 1 and 24 hours initiate remodeling events, which result in tooth movement 7 to 14 days later and that the minimum effective duration of a 40-gm activation is less than 1 hour in this animal model.     

大鼠正畸牙牙周膜中增殖细胞核抗原表达的研究

目的通过观察大鼠正畸牙移动过程中牙周膜内增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)的表达变化,探讨正畸过程中细胞增殖变化的机制。方法选用幼年SD大鼠,建立正畸牙移动模型,分别在加力后24 h、3 d、5 d、7 d、14 d、21 d处死动物,制备标本。进行免疫组化分析。结果对照组大鼠牙周组织中增殖细胞核抗原弱表达,实验组牙周膜中张力侧增殖细胞核抗原24 h时表达上调,3、5 d达最顶峰,7 d后逐渐下调,21 d趋于正常。结论正畸力促进牙周组织中细胞增殖,从而完成牙周组织的改建。     

大鼠正畸牙移动中Osterix的表达

目的：通过观察大鼠正畸牙移动过程中牙周膜内转录因子Osterix（Osx）的表达,初步探讨Osx与正畸矫治过程中牙周组织改建的关系。方法：将54只雄性SD大鼠随机分为9组,每组6只,即正畸加力0、3、6、12、24 h和3、5、7、14 d组,以右侧上颌第一磨牙不加力为自身对照组,左侧上颌第一磨牙为实验组,使用自制的加力装置移动磨牙并制备组织标本。SABC免疫组织化学法检测实验性大鼠正畸牙齿移动过程中牙周组织Osx的表达。结果：对照组大鼠牙周组织中Osx低表达,实验组于加力5 d时Osx表达水平达到最高,且张力区整体上比压力区阳性染色深。结论：正畸力作用下Osx参与牙周组织的改建,是正畸成骨的调控途径之一。     

局部应用二磷酸盐对鼠正畸牙移动影响的研究

目的 探讨局部注射Zoledronate溶液对鼠正畸牙齿移动距离与牙周组织形态的影响。方法 选用42只雄性Wistar大鼠，牵引其上颌第一磨牙近中移动。实验中分别将Zoledronate溶液及生理盐水注射入实验组（左侧）及对照组大鼠（双侧）上颌第一磨牙腭侧的粘骨膜下。注射于实验前3d开始，共进行9次，每3d一次。分别在加力0、3、7、14、21d后记录上颌第一磨牙移动距离，组织HE染色后，观察牙周组织形态学的改变。结果 ①实验组大鼠牙齿移动距离明显低于对照组。②实验组大鼠压力侧破骨细胞数在实验全过程中均低于对照组，而根分叉区破牙骨质细胞数除加力14d外，2组差异无显著性。③实验过程中Zoledronate溶液对破骨细胞和破牙骨质细胞以外的细胞作用不明显。结论 Zoledronate能有效地抑制支抗牙移动，减少压力侧牙槽骨表面破骨细胞数。     

MMP-3及TIMP-1在正畸牙周组织改建过程中的表达

目的：探讨大鼠正畸牙周组织改建过程中基质金属蛋白酶－３（ＭＭＰ－３）和金属蛋白酶组织抑制因子－１（ＴＩＭＰ－１）与正畸牙齿移动的关系。方法：在ＳＤ成年大鼠上颌左侧第一磨牙上颌切牙之间安置正畸装置,建立大鼠上移动实验模型。于牙齿移动１、３、５、７、１４ｄ后取材分别进行免疫组化染色,图像分析,观察ＭＭＰ－３和ＴＩＭＰ－１表达的变化。结果：牙齿移动１ｄ后,牙周组织细胞ＭＭＰ－３表达增强,５ｄ后ＭＭＰ－３     

实验性牙移动后三叉神经脊束核尾侧亚核CGRP的研究

目的：研究实验性牙移动过程中，三叉神经脊束核尾侧亚核(Vc)内降钙素基因相关肽(CGRP)的改变。方法：在大鼠左侧上颌第一、二磨牙间塞入一弹性橡皮圈模拟临床正畸加力状态。于不同加力时间点对三叉神经脊束核尾侧亚核进行CGRP免疫组化染色。结果：加力后6h和24h，实验侧三叉神经脊束核尾侧亚核CGRP样纤维明显少于对侧；施力3d后Vc浅层中CGRP样阳性终末与对照侧无明显差异，加力后1w大于对侧，2w时恢复至对侧水平。结论：实验性牙移动引起CGRP在三叉神经脊束核尾侧亚核释放。     

Increased expression of TRPV1 in the trigeminal ganglion is involved in orofacial pain during experimental tooth movement in rats

To investigate whether transient receptor potential vanilloid type 1 (TRPV1) is involved in pain induced by experimental tooth movement, experiments were performed in male Sprague‐Dawley rats weighing 200–250 g. Directed face‐grooming behavior was used to evaluate nocifensive behavior in rats during experimental tooth movement. The distribution of TRPV1 in the trigeminal ganglion (TG) was evaluated by immunohistochemistry, and its expression was detected by western blotting at several time points following the application of various magnitudes of force during tooth movement. Immunohistochemical analysis revealed that TRPV1 was expressed in TG, and its expression was increased after experimental tooth movement. Western blot results also showed that experimental tooth movement led to a statistically significant increase in expression of TRPV1 protein in TG. Meanwhile, the time spent on directed face‐grooming peaked on day 1 and thereafter showed a gradual decrease. In addition, both the change in TRPV1 expression in the TG and directed face‐grooming behavior were modulated in a force‐dependent manner and in concert with initial orthodontic pain responses. Our results reveal that TRPV1 expression is modulated by experimental tooth movement and is involved in tooth‐movement pain.     

下颌骨牵引成骨区即刻牙移动的实验研究

目的：研究下颌骨牵引成骨后在新骨区即刻牙移动时牙周组织的改建行为及牙移动规律。方法：选择4只牙列完整的Beagle犬,其中2只犬建立双侧下颌骨牵引成骨动物模型,牵引完成后,即刻以30g力远中移动下颌第三前磨牙进入牵引成骨区;另外2只犬拔除双侧下颌第四前磨牙后3个月,以30g力远中移动下颌第三前磨牙。实验中,每周加力1次拍摄X线片,并记录牙移动速率。牙移动8周后,观察实验牙及其牙周组织特点。测量数据采用SPSS12.0软件包进行t检验。结果：实验牙借助自制的持续加力装置移动进入牵引成骨区,实验牙未产生倾斜,牙无明显松动,牙根未见明显吸收。实验组牙移动速度显著快于对照组,P〈0.01。组组织学观察发现,牙槽骨和牙周膜未出现不可逆性损伤。结论：牵引成骨区的新生骨质中,牙可以快速而平稳地移动。     

牙周炎大鼠正畸牙移动张力侧牙周组织转化生长因子β1表达研究冰

目的研究炎性牙周条件下牙移动及牙周改建中转化生长因子β1（transforming growth factor—β1,TGF-β1）的表达。方法90只雄性SD大鼠随机分为为正常牙移动组、牙周炎牙移动组,通过对大鼠上颌第一磨牙的近中移动,在预定的0、0．5、1、2、3、5、7、14、21d时间点处死动物,运用免疫组织化学,检测牙移动张力侧TGF—β1蛋白表达强度及时间分布特点。结果正常牙移动组中,TGF-β1在牙周膜的成纤维细胞、成骨细胞和骨髓组织呈弱阳性表达,牙移动1d后,张力侧牙周膜区免疫染色的阳性反应明显增强,2d后达到高峰;牙周炎牙移动组,TGF-β1在破骨细胞、牙周膜成纤维细胞呈阳性表达,牙移动0．5d后,张力侧牙周膜区免疫染色的阳性反应明显增强,以后逐渐下降。结论牙周炎症影响正畸力效应下的牙周组织改建。     

Effect of misoprostol, a prostaglandin E1 analog, on orthodontic tooth movement in rats.

The purpose of this study was to investigate the effects of oral administration of misoprostol, a prostaglandin E1 analog, on orthodontic tooth movement and root resorption in rats. Sixty-four male Sprague-Dawley rats that initially weighed 250 +/- 20 g were used in this study. The animals were randomly assigned to 1 of 6 experimental and 2 control (nonappliance and appliance) groups. The experimental groups received 2.5, 5.0, 10.0, 25.0, 50.0, and 100.0 microg/kg misoprostol by gastric lavage every 24 hours for 2 weeks. A fixed orthodontic appliance consisting of a nickel-titanium closed-coil spring, 5.0 mm long was ligated between the maxillary right incisor and the maxillary right first molar. The initial activating force was 60 g. For analysis of root resorption, 99 maxillary right and left first molars from 61 animals were chosen. Serial histologic sections of the mesial root of the maxillary first molars were made, and histologic analysis of root resorption on the mesial and distal surfaces was performed. The results showed that oral misoprostol did increase the amount of orthodontic tooth movement in all the experimental groups compared with the appliance control group. This increase was statistically significant in doses of 10.0, 25.0, 50.0, and 100.0 microg/kg (P <.001). However, there were no statistically significant differences among these 4 different doses. There were no statistically significant differences in the amount of root resorption among the groups. However, a trend toward more root resorption was registered. On the basis of these findings, oral misoprostol can be used to enhance orthodontic tooth movement with minimal root resorption.     

前扣带回皮质层中牙移动疼痛相关蛋白质组学研究

目的研究正畸牙移动中前扣带回皮质层（ACC）的蛋白质组学表达,筛选牙移动疼痛相关的目标蛋白,探讨ACC在疼痛传导和形成中的作用。 方法30只雄性SD大鼠建立实验性牙移动模型后,根据行为学观测结果分组。实验组进行加力,对照组仅进行乙醚麻醉,24 h后进行行为学观测并取ACC组织,根据行为学观测结果选取4标样本进行蛋白质组学研究。ACC组织在提取蛋白并胰酶消化后,经串联质谱标记（TMT）试剂标记,进行液相色谱-串联质谱（LC-MS/MS）检测,并对差异表达蛋白进行生物信息学分析,进行基因本体（GO）注释,GO功能聚类分析,基因和基因组学京都百科全书（KEGG）代谢通路注释及功能聚类分析。 结果本实验共鉴定并定量3374种蛋白,其中表达上调蛋白12种、表达下调蛋白109种。GO注释和功能聚类分析中从生物过程、细胞组成、分子功能三个方面阐述了大鼠在实验性牙移动应力下发生的一系列应激反应及代谢调节。KEGG注释及功能聚类分析表明与炎症相关通路花生四烯酸通路及JAK-STAT信号通路表达下调,且差异具有统计学意义。花生四烯酸通路的前列腺素E合成酶（PGES）、谷胱甘肽过氧化物酶1（GPX1）、环氧化物水解酶2（EPHX2）,JAK-STAT信号通路的信号转导和转录因子1（STAT1）、STAT2显著下调,可能与炎症性疼痛的发生、发展密切相关。 结论TMT技术是组织蛋白质组学研究的有效方法。ACC在牙移动疼痛形成和调节中发挥重要作用,其中花生四烯酸通路、JAK-STAT信号通路可能是牙移动疼痛的关键信号通路。本实验为进一步探讨牙移动疼痛关键蛋白提供了重要的实验依据。     

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.