GSK-3β对正畸牙齿移动的影响

目的:观察GSK-3β对正畸牙齿移动距离的影响.方法:分别选30 只野生C57小鼠和20 只GSK-3β基因敲除C57小鼠.野生型和基因敲除型各20 只,正畸加力3、5、7、14 d(5 只/组)后处死,取材固定上颌骨扫描Micro CT测量牙齿移动距离,冰冻切片免疫荧光染色观察破骨情况.野生型10 只腹腔注射LiCl(隔天100 ng/ml)加力3 d,7 d处死后扫描MicroCT.结果:与野生型组同期结果相比,GSK-3β基因敲除小鼠牙齿移动距离降低(P<0.05),压力侧破骨细胞减少(P<0.05);基因敲除组与野生型注射LiCl组牙齿移动距离无统计学差异.结论:GSK-3β可以影响破骨细胞形成从而影响正畸牙齿移动.     

药物对牙齿移动的影响

多种外用药被用于提高正畸的效果,加速牙齿移动,巩固治疗成果,该文从加速牙齿移动和减缓牙齿移动两方面分述影响牙齿移动的药物。     

加快正畸牙齿移动的外源性因素

近年来,国内外学者为加快正畸牙齿移动作了许多研究。作者从激素和西药类(前列腺素、甲状旁腺素、肾上腺皮质激素、骨钙素)、中药类(丹参、灯盏花、夜来香油)、细胞因子类(血管内皮生长因子)以及物理方法类(激光、磁场、超声波和超短波)对目前已证明能加快正畸牙移动的外源性因素进行综述。     

灌服川续断水煎液对大鼠正畸牙移动及牙周组织中破骨细胞的影响

目的:研究中药川续断在大鼠正畸牙牙周组织改建中的作用机制及其对破骨细胞的影响.方法:选取48只SPF级Wistar雌性大鼠,随机分为川续断组和对照组,每组24只,建立大鼠正畸牙移动实验模型.川续断组每天灌服6g/ks川续断水煎剂,对照组每天灌服3mL生理盐水,2组动物均于正畸加力7、14、21、28d时分批次处死,每批次5只.分离大鼠上、下颌骨,测量牙移动的距离,同时制作上颌第一磨牙区牙周组织切片,光镜观察,并利用PASW statistics18软件进行数据处理,分别进行t检验和方差分析.结果:川续断组牙移动距离明显大于对照组,差异有统计学意义(P<0.05).光镜显示,川续断组牙周组织中破骨细胞数目明显增多,与对照组差异有显著(P<0.05).结论:川续断水煎液能促进大鼠正畸牙移动过程中破骨细胞的增殖和分化,促进牙槽骨吸收及其修复重建,有利于正畸牙移动.     

前列腺素与正畸牙齿移动

前列腺素作为一种炎症介质参与了正畸组织变化过程,同时也是重要的生物活性物质,在体内与其它免疫活性因子协同作用,调节和控制细胞的代谢活动,发挥生物效应。深入研究前列腺素在正畸中的作用机制对缩短矫正治疗疗程有着重要的意义。     

降钙素对小鼠牙齿萌出途中破骨细胞的影响

目的:在体研究降钙素对正常小鼠牙齿萌出过程中破骨细胞的影响,并分析其机制。方法:同一窝10只出生3d小鼠随机分成对照组和降钙素组,后者皮内注射鲑鱼降钙素每日1U/100g,连续3d。自注药起7d取其下颌骨,分别用酶组织化学和免疫组织化学的方法检测破骨细胞、RANKL阳性细胞在牙胚周围组织中的变化情况。结果:降钙素组的平均破骨细胞数、RANKL表达较对照组明显降低。结论:降钙素对正常小鼠牙齿萌出过程中的破骨细胞可能有抑制作用,这可为牙齿萌出的研究提供一定参考。     

消炎痛对正畸牙齿移动影响的研究

本研究选用健康的中国兔２０只，以２５克力推兔下牙远中移动，通过牙齿移动距离测量与组织学观察等方法观察消炎痛对正畸牙齿移动速度的影响，结果表明消炎痛可抑制牙周组织对正畸力的反应。建议在矫治之前应充分了解消炎痛类药物的用药史，以免影响矫治、延长疗程。     

消炎前对正畸牙齿移动中牙周组织超微结构的影响

目的：在细胞水平上进一步研究消炎痛影响正畸牙周组织改建与牙齿移动的机理。方法：通过扫描和透射显微镜（ＳＥＭ和ＴＥＭ），观察牙周组织细胞超微结构的改变。结果：ＳＥＭ和ＴＥＭ观察表明，２５ｇ力可引起兔切牙牙周组织细胞超微结构发生改变，在压力和张力侧均出现损伤和修复性反应，消炎痛对正畸牙周组织细胞超微结构变化的影响包括两方面，一方面抑制了牙周组织的炎症反应和挫伤，另一方面也抑制了组织的修复过程，从而抑制     

偏侧咀嚼对正畸牙移动影响的实验研究

目的通过建立偏侧咀嚼大鼠模型,探讨偏侧咀嚼对正畸牙移动过程的影响。方法选择30只6～8周龄,（250±10）g,雄性SD大鼠,随机分为实验组与对照组,每组各15只。通过拔除实验组大鼠右下颌所有磨牙使右上颌第一磨牙丧失咬合接触建立大鼠偏侧咀嚼动物模型,同时,在两组大鼠双侧上颌切牙和第一磨牙间放置镍钛拉簧,初始力值为50g,近中移动磨牙。分别于第0、3、7、10、14天测量大鼠上颌第一磨牙近中移动的距离并通过HE染色观察大鼠上颌第一磨牙牙周组织形态学变化。结果各时间点代偿性咀嚼增强侧牙移动速率均小于对照组（P〈0.05）,牙周组织变化与对照组相似;失咬合侧牙移动速率大于对照组（P〈0.05）,牙周组织出现退行性改变;但三种咬合状态下牙齿移动速率曲线均表现为瞬时运动、迟滞期及后期移动三个阶段。结论动物实验证实偏侧咀嚼引起正畸牙牙周组织发生相应改变最终影响牙移动速率,但无论牙移动速率快慢,牙移动均符合正畸性牙移动的一般规律。     

参与正畸牙移动的相关因子研究进展

牙周组织的改建是正畸牙移动的生物学基础。在牙冠上施加作用力引起牙周组织的微循环发生变化,发生短暂的急性炎症反应,牙周膜和牙槽骨细胞释放炎性介质、细胞因子、蛋白酶等,导致微环境的细胞发生增殖、分化,介导局部软硬组织的改建,牙齿从而移动到新的位置。到目前为止,正畸牙移动的生物学机理尚未完全阐明。该文主要从分子层面对一些影响正畸牙移动的相关分子作一综述。     

Osteoimmunology in orthodontic tooth movement

The skeletal and immune systems share a multitude of regulatory molecules, including cytokines, receptors, signaling molecules, and signaling transducers, thereby mutually influencing each other. In recent years, several novel insights have been attained that have enhanced our current understanding of the detailed mechanisms of osteoimmunology. In orthodontic tooth movement, immune responses mediated by periodontal tissue under mechanical force induce the generation of inflammatory responses with consequent alveolar bone resorption, and many regulators are involved in this process. In this review, we take a closer look at the cellular/molecular mechanisms and signaling involved in osteoimmunology and at relevant research progress in the context of the field of orthodontic tooth movement.     

Leukotrienes in orthodontic tooth movement

Prostaglandins (PGs) and leukotrienes (LTs) are products of arachidonic acid conversion. PGs have an established role in mediating orthodontic tooth movement. The role of LTs in modulating or mediating orthodontic tooth movement was investigated in this study. One hundred thirty-two Sprague-Dawley rats were used; the animals weighed 300 to 400 gm with equal numbers of male and female rats. They were divided into five main groups of 24 animals each and a sham group of 12 animals. An orthodontic appliance was placed and activated on all the animals except the sham group; in this group the appliances were not active. Each main group was given one of the following treatments daily: distilled water, 5% gum arabic solution, PG synthesis inhibitor indomethacin, LT synthesis inhibitor AA861, and a combination of both drugs. Each group was divided into six subgroups of four animals; the animals were killed at either 1, 3, 5, 7, 10, or 14 days, and tooth movement measured. The three sham subgroups received distilled water and were killed at 1, 7, or 10 days. The first maxillary molar (the moved tooth) and surrounding tissues were removed from all animals in the sham group and the subgroups killed at 1, 7, and 10 days in the gum arabic solution group and the LT synthesis inhibitor group. Prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) were extracted, measured with radioimmunoassay (RIA), and standardized per milligram of protein in the sample. A significant inhibition of tooth movement occurred beginning on day 7 in the indomethacin, AA861, and combination groups; there was no significant difference among these groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intermittent force in orthodontic tooth movement

A single orthodontic activation lasting one hour can initiate tooth movement. The purpose of this study is to examine tooth movement, osteoclasts, and root resorption in rats following several one-hour activations. Rats (n = 144) were randomly assigned to intermittent (multiple activations of 1 hr/day), continuous, and sham appliances. Twelve rats were killed at 3, 5, 7, and 14 days. Tooth movement, osteoclasts, osteoclast %, and root resorption % were quantified. Continuous force moved molars mesially at days 3 and 14 (p < 0.05), but intermittent and sham did not. Intermittent and continuous force increased osteoclast numbers at days 3, 5, and 7 (p < 0.05). Continuous force increased osteoclast surface on days 3 and 14 (p < 0.05). Continuous force increased root resorption at days 5, 7, and 14 (p < 0.05). These results demonstrate that orthodontic force for one hour in 24 stimulates osteoclasts at compression sites but does not stimulate tooth movement or root resorption.     

帕米膦酸钠对大鼠正畸牙移动过程中破牙骨质细胞及破骨细胞分化因子表达的影响

目的:研究帕米膦酸钠对大鼠正畸牙移动过程中牙周组织压力侧破牙骨质细胞及破骨细胞分化因子(ODF)表达的影响.方法:选择24只6周龄SPF级健康雌性Wistar大鼠,建立正畸牙移动动物模型,每只大鼠上颌分实验侧和对照侧,于安装矫治器前3d,于实验侧大鼠第一磨牙近中腭侧黏骨膜下注射帕米膦酸钠50 μL,对照侧注射0.9％生理盐水50 μL,每3d注射1次.于正畸加力3、7、14 d时分批处死8只大鼠,制作牙周组织切片,观察破牙骨质细胞数量,免疫组化观察ODF的表达情况.采用PASW Statistics 18软件包对实验数据进行统计学处理.结果:实验侧在3、7、14d时,第一磨牙压力侧破牙骨质细胞的数目均少于对照侧,其中,7、14d时两侧差异显著(P＜0.05);实验侧在3、7、14d时,第一磨牙压力侧ODF阳性表达均低于对照侧,其中,7、14 d时两侧差异显著(P＜0.05).结论:局部注射二膦酸盐帕米膦酸钠能够减少大鼠正畸牙移动过程中牙周组织压力侧破牙骨质细胞的数量及ODF的阳性表达.     

Estrous-cycle-dependent variation in orthodontic tooth movement

Sex hormones, including estradiol, play important physiological roles in bone metabolism. The purpose of this study was to investigate whether there is estrous-cycle-dependent variation in orthodontic tooth movement, and, if so, to determine the mechanism. Ten-week-old female Wistar rats were used. They received repeated orthodontic force during specific phases in the estrous cycle. Tooth movement in animals that received force principally in estrus was about 33% greater than that in animals that received such force principally in pro-estrus (p < 0.05). Serum estradiol levels also varied according to the estrous cycle, with a peak during pro-estrus and a nadir during estrus, and were inversely related to tooth movement. Furthermore, there were negative correlations between estradiol and both serum TRAP activity and pyridinoline (r = -0.42, p < 0.05; r = -0.59, p < 0.001). These results suggest that cyclic changes in the estradiol level may be associated with the estrous-cycle-dependent variation in tooth movement through its effects on bone resorption.     

Mechanisms of tooth eruption and orthodontic tooth movement

Teeth move through alveolar bone, whether through the normal process of tooth eruption or by strains generated by orthodontic appliances. Both eruption and orthodontics accomplish this feat through similar fundamental biological processes, osteoclastogenesis and osteogenesis, but there are differences that make their mechanisms unique. A better appreciation of the molecular and cellular events that regulate osteoclastogenesis and osteogenesis in eruption and orthodontics is not only central to our understanding of how these processes occur, but also is needed for ultimate development of the means to control them. Possible future studies in these areas are also discussed, with particular emphasis on translation of fundamental knowledge to improve dental treatments.     

正畸大鼠磨牙牙周膜内破骨细胞的出现与应力的关系

目的 :探讨正畸力作用下大鼠磨牙牙周膜内破骨细胞出现与应力的关系 ,寻找最佳正畸力。方法 :将大鼠磨牙近中移动两周 ,计数同一牙的五张牙周切片的破骨细胞总数 ,建立三维有限元模型 ,观察破骨细胞出现区的应力特点。结果 :40 g力值组破骨细胞总数明显高于 10 0 g力值组 ;78.2 %的破骨细胞出现在应力在牙齿移动方向上的分量 (S11)为± (2 0～ 2 6 )g/cm2 的等值应力线经过的牙周膜内。结论 :破骨细胞的出现与S11关系密切 ,当S11不超过毛细血管平均压力时破骨细胞较为活跃。