女性正畸患者月经周期中最佳加力时机的初步研究

目的 通过在女性月经周期中的不同时期对正畸牙加力,研究龈沟液内雌激素（E2）、骨钙素（OCN）、核因子κ B受体活化因子配体（RANKL）、骨保护素（OPG）的时效性表达,从而为临床选择最佳加力时机提供理论依据。方法 选取18~28周岁双侧对称拔除第一恒前磨牙青年女性恒牙患者12人。随机选取其中6人为月经期加力组,6人为排卵期加力组,于右侧尖牙单侧使用镍钛拉簧施加1.5 N正畸力使之远中移动,对侧尖牙不做处理。使用牙周滤纸分别于加力前,加力后15、30、45 d取右侧尖牙远中（压力侧）龈沟液样本。使用化学发光法测定龈沟液中E2、OCN的活性水平。使用酶联免疫法检测龈沟液中RANKL及OPG的活性水平。结果 排卵期加力组龈沟液E2和OCN水平高于月经期加力组（P<0.05）。月经期加力组与排卵期加力组中RANKL水平与OPG水平及RANKL/OPG比值均未见明显差异（P>0.05）。结论 女性正畸拔牙患者于雌激素水平较高的排卵期施加正畸力,骨保护因子E2、OCN表达增强,不利于牙槽骨改建。而于月经期加力,上述因子表达减弱,可能有助于牙齿快速移动。     

正畸力作用轻度牙周炎患牙后龈沟液中RANKL、OPG的表达

目的检测正畸力作用轻度牙周炎患牙后龈沟液中核因子κB受体活化子配体(receptor activator for NF-κB ligand,RANKL)、骨保护素(Osteoprotegerin,OPG)的浓度变化,探讨正畸力是否加重患牙的牙周损伤。方法选择20例无牙周炎病史正畸患者和20例伴有轻度牙周炎但炎症已被控制的正畸患者;分别在正畸加力后0 h、1 h、24 h、7 d、14 d、21 d收集上颌双侧尖牙远中龈沟液;应用酶联免疫吸附(enzyme-linked immune sorbent assay,ELISA)实验测定龈沟液中RANKL、OPG浓度;分析正畸过程中RANKL、OPG的变化趋势及两者比值。结果在正畸加力后各时间点,两组患者龈沟液中RANKL、OPG浓度无明显差异(P>0.05),除加力后7 d外,其他时间点龈沟液中RANKL/OPG比值无差异(P>0.05);以加力后0 h作对照,各时间点组内患者龈沟液中RANKL浓度均升高(P<0.05),在加力后7 d达到最大值;而各时间点组内患者龈沟液中OPG浓度均降低(P<0.01),在加力后7 d,OPG浓度最低;此外,RANKL/OPG比值均增加,同样在加力后7 d达到最大值。结论在相同正畸力作用下,伴牙周炎患牙牙周组织骨改建活动无明显异常;因此,恰当的正畸力不会引起轻度牙周炎患牙牙周病变加重。     

正畸牙龈沟液白细胞介素-1β与肿瘤坏死因子-α水平的变化及其生物学意义

目的　 探讨正畸牙受力后龈沟液内白细胞介素-１β（IL-1β）和肿瘤坏死因子-α（TNF-α）水平的动态变化及其生物学意义。方法 　选择15例正畸患者为研究对象，将每位患者的4颗尖牙按左右侧随机分入实验组和对照组。实验组用橡皮链加力拉尖牙向远中，对照组尖牙不加力。分别在戴矫治器前，戴矫治器后1、24、48、72和168 h时收集两组尖牙远中颊面龈沟液，应用放射免疫法测定龈沟液内IL-1β和TNF-α的含量。结果 　实验组在加力24 h后IL-1β和TNF-α水平开始升高，72 h达到最高，168 h基本恢复至基线水平；对照组在整个实验过程中IL-1β和TNF-α含量均保持在基线水平。48 h和72 h实验组IL-1β和TNF-α含量与对照组相比有显著性差异（P＜0.05）。24 h实验组 TNF-α含量与对照组有显著性差异（P＜0.05），而IL-1β含量与对照组相比无显著性差异（P＞0.05）。结论　 牙齿正畸过程中受机械力的作用龈沟液内IL-1β和TNF-α水平发生动态变化，表明这两种生物活性因子早期即参与牙齿移动和牙槽骨重建过程。     

正畸力作用下龈沟液中氧自由基的变化研究

目的探讨正畸力作用下不同时间龈沟液（GCF）中氧自由基的变化。方法选择10例正畸患者作为研究对象．分别在对实验牙加力前和加力后第1、2、3、4、5、6周收集GCF并检测GCF中超氧化物岐化酶（SOD）的活力和丙二醛（MDA）的含量。结果与对照牙相比,实验牙被加力后第3、4周GCF中氧自由基的含量明显增加,差异有统计学意义,其余检测时间点未见明显变化。结论正畸力可导致GCF中氧自由基含量升高．有可能造成牙周组织损伤,对正畸临床加力有一定的指导意义。     

不同正畸力值下人龈沟液白细胞介素-1β和可溶性细胞黏附分子-1水平的变化

目的:探讨不同正畸力值下龈沟液内白细胞介素-1β(IL-1β)和可溶性细胞黏附分子-1(sICAM-1)水平的动态变化及其临床意义。方法:收集正畸科门诊中符合实验条件的32例病人,随机分成4组(A,B,C,D组),每组8人。分别对其一侧的尖牙施加0、100、150、250 g的远中移动的初始力。分别在加力前0 d及加力后1、3、7、14、21、28 d收集龈沟液(GCF),应用ELISA法测定GCF中IL-1β和sICAM-1的含量。结果:B组和C组GCF中IL-1β含量在加力后1、3、7 d持续升至高峰,然后下降,28 d基本恢复到基线水平;sICAM-1含量在加力后1、3 d持续升至高峰,然后下降,28 d基本恢复到基线水平。D组GCF中IL-1β含量在加力后1 d开始明显增高,于3 d升至高峰,之后7 d维持在较高水平,14 d开始下降,28 d基本恢复到基线水平;D组GCF中sICAM-1含量在加力后1、3 d持续升至高峰,然后下降,28 d基本恢复到基线水平。D组加力后1、3、7、14、21 d时GCF中IL-1β和sICAM-1含量明显高于其余3组(P<0.05)。结论:牙齿正畸过程中龈沟液内IL-1β和sICAM-1含量与正畸力大小及力的持续时间密切相关,两者含量的检测有助于临床了解和监测正畸病人牙周情况。     

尖牙受力后龈沟液中碱性磷酸酶水平的变化

目的:通过分析上颌尖牙受不同作用力后龈沟液(GCF)中的碱性磷酸酶(ALP)水平的动态变化规律,间接了解牙齿受机械力作用后牙周组织改建的生化反应过程。方法:选择28例正畸患者为研究对象,随机分成4组。分别对其右侧上颌尖牙施加50 g、100 g、150 g、250 g的远中移动初始力,左侧上颌尖牙不加力为对照组。分别在加力前、加力后24 h、48 h、72 h、7 d、14 d、21 d和28 d时收集尖牙近、远中龈沟内GCF,并检测ALP含量。结果:不同时间点、不同力值下GCF中ALP水平变化差别有统计学意义(P<0.001),而牙齿近远中侧GCF中ALP水平变化差别无统计学意义。结论:GCF中ALP的水平与正畸力大小及力的持续时间密切相关;GCF中ALP含量的变化可以作为分析临床正畸加力大小是否合适的参考指标之一。     

不同正畸力值作用下龈沟液中天冬氨酸转氨酶水平的变化

目的:通过分析上颌尖牙受不同作用力后龈沟液(GCF)中的天冬氨酸转氨酶(Aspartate aminotrans-ferase,AST)水平的动态变化规律,间接了解牙齿受机械力作用后牙周组织改建的生化反应过程。方法:选择正畸患者28例为研究对象,随机分成4组。分别对4组患者的右侧上颌尖牙施加50g、100g、150g、250g的远中移动初始力,左侧上颌尖牙均不加力。分别在加力前、加力后1、2、3、7、14、28d时收集尖牙近、远中龈沟内GCF,SYS-MEX全自动生化分析仪检测AST含量。结果:不同时间点、不同力值下GCF中AST水平变化差别有统计学意义(P<0.001),而牙齿近远中侧GCF中AST水平变化也有明显的无统计学意义。结论:GCF中AST的水平与正畸力大小及力的持续时间密切相关;GCF中AST含量的变化可以作为分析临床正畸加力大小是否合适的参考指标之一。     

Smart Clip自锁托槽和传统托槽对正畸牙龈沟液中炎症因子水平的影响研究

目的 探讨自锁矫治器和传统矫治器对牙齿加力后龈沟液中炎症因子水平变化从而比较两种类型托槽引起的牙周组织改建的情况。方法 选择16例上颌前突需拔除上颌双侧第一前磨牙的患者,上牙列一侧使用自锁矫治器作为试验组,一侧使用传统直丝弓矫治器作为对照组,对两侧尖牙加力后取不同时间点的龈沟液,检测其中IL-1β和PGE2水平,分析其变化与牙周组织炎症反应的关系。结果 在对尖牙加力后,龈沟液中IL-1β和PGE2水平均升高,均在加力后24 h达到最高值,各检测时间点试验组和对照组龈沟液中IL-1β和PGE2含量差异无统计学意义(P﹥0.05)。结论 2种矫治器在正畸牙移动的初期对牙周组织改建的影响无明显区别。     

牙周炎牙齿正畸加力前后龈沟液中PGE2和ALP的变化

目的 :探讨牙周炎牙齿接受正畸治疗时牙周组织的反应。方法 :在牙周炎和牙周健康正畸组分别放置标准方丝弓矫治装置 ,一侧 (实验侧 )加力 ,另一侧 (对照侧 )未加力 ,分别于加力前和加力 2 4h后收集龈沟液 ,采用放射免疫法和生化分析法进行前列腺素E2 (PGE2 )和碱性磷酸酶 (ALP)检测。结果 :正畸加力 2 4h后实验侧 2组龈沟液中PGE2 总量均明显增加 (P <0 .0 1) ,2组PGE2 总量变化的差值无显著性差异 ,对照侧均无变化 (P >0 .0 5 ) ;2组龈沟液中ALP总量变化不明显。结论 :牙周炎牙齿在接受正畸治疗 2 4h时 ,龈沟液中PGE2 和ALP的改变与牙周健康牙齿的反应类似。     

正畸移动牙龈沟液中IL-1β和sICAM-1的表达

目的探讨成人牙齿受到正畸力后龈沟液中白细胞介素-1β（IL-1β）和可溶性细胞粘附分子-1（slCAM-1）的表达。方法选择27例已拔除双侧上颌第一前磨牙的患者，用弹簧施力于其一侧上颌尖牙向远中，为实验组；对侧不受力，为对照组。分别于施力前、施力后1、2、3、7、21、28天用ELISA法检测双侧上颌尖牙龈沟液（GCF）中IL-1β和sICAM-1的含量。结果实验组在受力后龈沟液中IL-1β和sICAM-1均开始升高，第3天达到高峰，第28天基本回落至基线。对照组GCF中IL-1β和sICAM-1基本维持在基线。第2、3天实验组GCF中IL-1β的含量和第2、3、7天sICAM-1的含量与对照组相比有显著性差异（P〈0．05）。结论在正畸过程中，牙齿GCF中IL-1β和sICAM-1的表达随牙周组织的受力改变而发生动态变化，与牙齿移动和牙槽骨重建有关，可作为一种临床检测方法。     

Composition changes in gingival crevicular fluid during orthodontic tooth movement: comparisons between tension and compression sides

The aim of this study was to evaluate whether the application of tension or compression forces exerted on the periodontium during the early phase of orthodontic tooth movement is reflected by differences in the composition of the gingival crevicular fluid (GCF), at the level of interleukin-1beta (IL-1beta), substance P (SP), and prostaglandin E(2) (PGE(2)). Eighteen children (mean age 10.8 yr) starting orthodontic treatment were included in the study. Molar elastic separators were inserted mesially to two first upper or lower molars. One of the antagonist molars served as the control. GCF was collected from the mesial and distal sites of each molar, before (-7 d, 0 d) and immediately after (1 min, 1 h, 1 d, and 7 d) the placement of separators. The levels of IL-1beta, SP, and PGE(2) were determined by enzme-linked immunosorbent assay. At the orthodontically moved teeth, the GCF levels of IL-1beta, SP, and PGE(2) were significantly higher than at the control teeth in both tension and compression sides, and at almost all occasions after insertion of separators. The increase, relative to baseline values, was generally higher in tension sides. For the control teeth, the three mediators remained at baseline levels throughout the experiment. The results suggest that IL-1beta, SP, and PGE(2) levels in the GCF reflect the biologic activity in the periodontium during orthodontic tooth movement.     

Aspartate aminotransferase activity in gingival crevicular fluid during orthodontic treatment. A controlled short-term longitudinal study

BACKGROUND: During orthodontic tooth movement, the early response of periodontal tissues to mechanical stress involves an acute inflammatory response, with a sequence characterized by periods of activation, resorption, reversal, and formation in both tension and compression sites. This study used a longitudinal design to examine aspartate aminotransferase (AST) activity in gingival crevicular fluid (GCF) in order to assess whether AST in GCF has potential as a possible diagnostic aid to monitor tooth movement and tissue response during orthodontic treatment. METHODS: Eighteen patients (mean age, 16.1 years) participated in the study. An upper first molar from each patient undergoing treatment for distal movement served as the test tooth (TT), with its contralateral (CC) and antagonist (AC) first molars used as controls. The CC was included in the orthodontic appliance, but was not subjected to the orthodontic force; the AC was free from any orthodontic appliance. The GCF around the experimental teeth was collected from both mesial and distal tooth sites immediately before appliance activation, 1 hour after, and weekly over the following 4 weeks. Clinical gingival condition was evaluated at baseline and at the end of the experimental period. AST activity was determined spectrophotometrically at 30 degrees C, and the results were expressed as total AST activity (mU/sample). RESULTS: Throughout the experiment, AST levels were significantly elevated in all sites from the TT and CC groups compared to the AC group where, conversely, AST activity remained at the baseline level. However, enzyme levels in the TT group were significantly greater than in the CCs at tension sites on day 14, and in compression sites on days 7 and 14. Moreover, AST activity from the TT group was significantly greater in compression sites than in tension sites on day 7; this was not observed for the CCs. CONCLUSIONS: Our results suggest that AST levels in GCF reflect the biological activity which occurs in the periodontium during controlled occlusal trauma and, therefore, should be further evaluated as a diagnostic tool for monitoring correct orthodontic tooth movement in clinical practice.     

Alkaline phosphatase activity in gingival crevicular fluid during human orthodontic tooth movement.

Bone remodeling that occurs during orthodontic tooth movement is a biologic process involving an acute inflammatory response in periodontal tissues. A sequence characterized by periods of activation, resorption, reversal, and formation has been recently described as occurring in both tension and compression tooth sites during orthodontic tooth movement. We used a longitudinal design to investigate alkaline phosphatase (ALP) activity in gingival crevicular fluid (GCF) to assess whether it can serve as a diagnostic aid in orthodontics. Sixteen patients (mean age, 15.5 years) participated in the study. The maxillary first molars under treatment served as the test teeth (TT) in each patient; in particular, 1 first molar was to be retracted and hence was considered the distalized molar (DM), whereas the contralateral molar (CM) was included in the fixed orthodontic appliance but was not subjected to the distal forces. The DM antagonist first molar (AM), free from any orthodontic appliance, was used as the baseline control. The GCF around the experimental teeth was harvested from mesial and distal tooth sites immediately before appliance activation, 1 hour after, and weekly over the following 4 weeks. The clinical gingival condition was evaluated at the baseline and at the end of the experimental term. ALP activity was determined spectrophotometrically at 30 degrees C, and the results were expressed as total ALP activity (mUnits/sample). GCF ALP activity was significantly elevated in the DMs and the CMs as compared with the AMs at 1, 2, 3, and 4 weeks; conversely, in the AMs, GCF ALP activity remained at baseline levels throughout the experiment. Moreover, the enzyme activity in the DMs was significantly greater than in the CMs. In the DMs, a significantly greater ALP activity was observed in sites of tension compared with sites of compression. This difference was not seen with the CMs, in which the enzyme activity increased to the same extent in tension and compression sites. These results suggest that ALP activity in GCF reflects the biologic activity in the periodontium during orthodontic movement and therefore should be further investigated as a diagnostic tool for monitoring orthodontic tooth movement in clinical practice.     

Relationship between substance P and interleukin-1beta in gingival crevicular fluid during orthodontic tooth movement in adults

Metabolism by peptidases plays an important role in modulating the levels of biologically-active neuropeptides, while that of substance P (SP), a component of gingival crevicular fluid (GCF), may potentiate the inflammatory process in orthodontic tooth movement. The aim of this study was two-fold: (1) to investigate GCF levels of SP and interleukin-1beta (IL-1beta) during human orthodontic tooth movement, and (2) to determine the correlation coefficients between SP and IL-1beta levels in the GCF. The subjects were 3 males, with a mean age of 21.3 +/- 2.8 years old, and 6 females, with a mean age of 23.1 +/- 2.4 years, undergoing orthodontic movement of a single tooth, with the contralateral tooth used as the control. GCF was sampled at the control and treatment (compression) sites before and 1, 4, 8, 24, 72, 120, and 168 hours after initiation of orthodontic treatment. Prevention of plaque-induced inflammation allowed assessment of the dynamics of mechanically stimulated SP and IL-1beta levels in the GCF, which were determined using enzyme-linked immunosorbent assay (ELISA) kits. GCF levels of SP and IL-1beta for the treated teeth were significantly higher (P < 0.001) than for the corresponding control teeth from 8 to 72 hours, and peaked at 24 hours. These results show that the amounts of SP and IL-1beta in GCF increase with orthodontic tooth movement, and indicate that such increases may be involved in inflammation in response to mechanical stress.     

广泛型侵袭性牙周炎患者龈沟液中白介素-17的检测

目的 比较广泛型侵袭性牙周炎患者与健康人龈沟液中白介素-17(IL-17)的表达水平及与临床指标的关系。方法 选择广泛型侵袭性牙周炎患者18例和健康人16例,共68颗牙,记录临床牙周检查指标,用滤纸条法收集龈沟液。采用抗体夹心ELISA法测定广泛型侵袭性牙周炎患者治疗前、治疗后3个月及健康对照者龈沟液中IL-17总量和浓度。结果 广泛型侵袭性牙周炎患牙治疗前龈沟液中IL-17的总量和浓度高于牙周健康牙,基础治疗3个月后广泛型侵袭性牙周炎患牙龈沟液中IL-17的总量和浓度较治疗前下降。广泛型侵袭性牙周炎患牙龈沟液中IL-17浓度与探诊深度、附着丧失和出血指数呈正相关关系,而IL-17总量仅与探诊深度呈正相关关系。结论 龈沟液中IL-17浓度可能与广泛型侵袭性牙周炎牙周破坏及炎症的严重程度相关。?     

The level of cathepsin B in gingival crevicular fluid during human orthodontic tooth movement

This investigation examined gingival crevicular fluid (GCF) levels of lysosomal cystein protease, cathepsin B (CAB), during human orthodontic tooth movement. The study included 10 patients (five males, mean age 22.5 +/- 2.8 years and five females, mean age 23.4 +/- 3.9 years), each having one tooth undergoing orthodontic movement, while the contralateral and antagonist teeth were used as the controls. The GCF was sampled at the control and treatment (compression) sites before activation and at 1, 24, and 168 hours. Prevention of plaque-induced inflammation allowed this study to focus on the dynamics of mechanically stimulated CAB levels in GCF. The CAB levels in GCF were determined by fluorospectrometry, using Z-Arg-Arg-MCA as the substrate and by Western blotting analysis. The GCF levels of CAB for the treated teeth were significantly (P< 0.001) higher than those of the control teeth at 24 hours. At the control sites, CAB levels at 24 hours did not change significantly with time. At the experimental site where orthodontic forces were applied, Western blot analysis demonstrated that the molecular forms were 29 kDa mature enzymes. These results indicate that the amount of CAB in GCF is increased by orthodontic tooth movement. This increased CAB may be involved in extracellular matrix degradation in response to mechanical stress.     

Longitudinal monitoring of subgingival colonization by Actinobacillus actinomycetemcomitans, and crevicular alkaline phosphatase and aspartate aminotransferase activities around orthodontically treated teeth

OBJECTIVES: During orthodontic treatment, changes in subgingival plaque colonization and tissue inflammation and remodelling have been described. This study uses a longitudinal design to examine subgingival colonization of Actinobacillus actinomycetemcomitans (Aa) and alkaline phosphatase (ALP) and aspartate aminotransferase (AST) activities in gingival crevicular fluid (GCF) in order to assess whether these parameters have potential as biomarkers of tissue responses to orthodontic tooth movement in humans. MATERIALS & METHODS: Twenty-one patients (ages: 11.2-22.5; mean 17.1 +/- 3.3 years) participated in the study. An upper canine from each patient undergoing treatment for distal movement served as the test tooth (DC), and its contralateral (CC) and antagonist (AC) canines were used as controls. The CC was included in the orthodontic appliance, but was not subjected to the orthodontic force; the AC was free from any orthodontic appliance. The subgingival plaque and GCF around the experimental teeth was harvested from both mesial and distal tooth sites immediately before appliance activation and on day 28. Clinical gingival condition was evaluated at the baseline and at the end of the experimental period. Aa colonization was determined by culture methods, while ALP and AST activities were evaluated spectrophotometrically. RESULTS: Throughout the study, the clinical conditions worsened in both the DCs and the CCs as compared with the baseline, whereas no significant differences were found between the DCs and the CCs, or between mesial and distal sites of each of these teeth on day 28. In the ACs, clinical parameters remained at baseline levels throughout the study. Similar results were found for Aa colonization, which increased significantly on day 28 in the DC and CC groups. On day 28, ALP and AST activities were significantly elevated in all sites from the DC and CC groups as compared with the ACs, where, conversely, enzymatic activities remained at the baseline levels. However, ALP activity in the DC group was significantly greater than in the CCs at mesial (tension) sites on day 28, while AST activity in the DCs was significantly elevated as compared with the CC group at the distal (compression) sites. Greater ALP activity in the DC group was observed at the tension sites compared with the compression sites on day 28. CONCLUSIONS: Our results suggest that Aa subgingival colonization, and ALP and AST activities in GCF reflect the tissue responses that occur in the periodontium during orthodontic treatment.     

Lactate dehydrogenase activity in human gingival crevicular fluid during orthodontic treatment: a controlled, short-term longitudinal study

BACKGROUND: During orthodontic tooth movement, the early response of periodontal tissues to mechanical stress is an acute inflammatory one. This study uses a longitudinal design to examine lactate dehydrogenase (LDH) activity in gingival crevicular fluid (GCF) to determine if GCF LDH can be used as a diagnostic aid in monitoring tooth movement and tissue response during orthodontic treatment. METHODS: Seventeen patients (mean age: 16.1 years) participated in the study. Each patient was undergoing treatment for distal movement, and an upper first molar served as the test tooth (TT), while the contralateral (CT) and antagonist (AT) teeth were used as controls. The CT was included in the orthodontic appliance, but was not subjected to the distal movement; the AT was free from any orthodontic appliance. The GCF around the experimental teeth was harvested from both mesial and distal tooth sites immediately before appliance activation, and on days 7, 14, and 21. Clinical gingival conditions were also recorded. RESULTS: Gingival crevicular fluid LDH activity was significantly elevated in all sites of the TT and CT, as compared to the AT, where LDH activity remained at the baseline level throughout the study. Enzyme activity levels were also greater in the TT than in the CT, and in the compression sites. CONCLUSIONS: Our results suggest that GCF LDH levels reflect the biological activity that takes place in the periodontium during orthodontic movement, and therefore they can be used as a diagnostic tool for monitoring for correct orthodontic tooth movement in clinical practice.     

Biochemical markers of bone metabolism in gingival crevicular fluid during early orthodontic tooth movement

Objective:To evaluate the expression of an activator of nuclear factor-kappa (RANK), osteoprotegerin (OPG), osteopontin (OPN), and transforming growth factor ß1 (TGF-ß1) in gingival crevicular fluid (GCF) of teeth subjected to orthodontic forces.Materials and Methods:A randomized, pilot clinical trial including 10 healthy volunteers was conducted using a split-mouth design. Orthodontic elastic separators were placed between the second premolar and first molar, with the contralateral quadrant serving as a control. The GCF samples were collected from the tension and compression sites at baseline, 24 hours, and 7 days after the placement of separators. The GCF sample volumes were measured using a Periotron 8000, and total protein concentrations were determined. Levels of RANK, OPG, OPN, and TGF-ß1 were also analyzed using a multiplex enzyme-linked immunosorbent assay.Results:The control sites remained unchanged throughout the study. In contrast, the concentration of OPG significantly decreased at the compression site by 24 hours, and the amount and concentration of RANK differed significantly between the control, compression, and tension sites after 7 days. A significant increase in absolute TGF-ß1 levels was also detected at the compression site versus the control and tension sites after 7 days.Conclusion:Bone metabolism is affected by application of force to the teeth by elastic separators. Both increased expression of bone resorptive mediators (eg, RANK and TGF-ß1) and decreased expression of a bone-forming mediator (eg, OPG) on the compression side were detected.     

Matrix metalloproteinases and chemokines in the gingival crevicular fluid during orthodontic tooth movement

Matrix metalloproteinases (MMPs) and monocyte chemoattractants are key modulators of the biological mechanisms triggered in the periodontium by mechanical forces. The gingival crevicular fluid (GCF) provides a non-invasive method to assess longitudinally the release of inflammatory mediators during orthodontic tooth movement. The goal of this study was to examine the GCF levels of MMP-3, MMP-9, and MMP-13 and of the chemokines macrophage inflammatory protein (MIP)-1β, monocyte chemoattractant protein (MCP)-1, and regulated on activation normal T cells expressed and secreted (RANTES) at different time points during orthodontic tooth movement. Fourteen subjects (three males and 11 females, 18.8 ± 4.8 years of age; range from 12 to 28 years) had their maxillary canines retracted. Thirty-second GCF samples were collected from the tension and pressure sides 7 days prior to the activation of the orthodontic appliance, on the day of activation, and after 1 and 24 hours, and 14, 21, and 80 days of constant force application. The volume of GCF was measured and samples analysed using a multiplexed bead immunoassay for the content of the six target molecules. Differences in the mean GFC volumes and mean level for each analyte over time were assessed using the Friedman test, and differences between the tension and pressure sides at each time point with the Mann-Whitney test. The mean levels of the three MMPs changed significantly over time but only at the compression side (P < 0.05, Friedman test). The GCF levels of the three chemokines were not affected by the application of mechanical stress. The levels of MMPs in GCF at the pressure side are modulated by the application of orthodontic force.