Effects of aging on RANKL and OPG levels in gingival crevicular fluid during orthodontic tooth movement

OBJECTIVES: To compare the levels of the receptor activator of NFkB ligand (RANKL) and osteoprotegerin (OPG) in the gingival crevicular fluid (GCF) during orthodontic tooth movement in juvenile and adult patients. DESIGN: Fifteen juveniles and 15 adults served as subjects. GCF was collected from the distal cervical margins of the experimental and control teeth at 0, 1, 24, and 168 h after application of a retracting force. Enzyme-linked immunosorbent assay kits were used to determine RANKL and OPG levels in the GCF samples. RESULTS: The amount of tooth movement for juveniles was larger than for adults after 168 h. Further, after 24 h RANKL levels were increased and those of OPG decreased in GCF samples from the compression side during orthodontic tooth movement in both juveniles and adults. The RANKL/OPG ratio in GCF from adult patients was lower than that in the juvenile patient samples. CONCLUSION: Our results suggest that the age-related decrease in amount of tooth movement may be related to a decrease in RANKL/OPG ratio in GCF during the early stages of orthodontic tooth movement.     

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.     

Bone marker levels in gingival crevicular fluid during orthodontic intrusive tooth movement: a preliminary study

The aim of the present study is to observe the changes in bone turnover markers, deoxypyridinoline (Dpd), osteocalcin, n-telopeptide (NTx), and bone alkaline phosphatase (balp) during the experimental orthodontic intrusion of maxillary premolar teeth. The study population required fixed appliance therapy involving the extraction of the maxillary first premolar teeth. Gingival crevicular fluid (GCF) samples were collected from each patient by using paper strips before the appliances were fitted and 1, 24, and 168 hours after the activation of appliances. After the second activation on the 21st, 22nd, and 28th days of the study, samples were collected. Enzyme-Linked Immunosorbent Assay (ELISA) tests were performed following manufacturer's recommendations. The results of the study indicate Dpd, osteocalcin, and balp values decrease with force application. Among the tested parameters only Dpd values showed statistically significant changes through time. One, 7, 22, and 28 day results show a significant amount of decrease when compared to 0 days. The extra decrease on the 22nd day (the day after the second activation) is also significantly lower. NTx crosslink values could not be detected in the experimental samples.     

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.     

Glycosaminoglycans in human gingival crevicular fluid during orthodontic movement

Glycosaminoglycans (GAG) in gingival crevicular fluid (GCF) were investigated by cellulose acetate electrophoresis of simultaneously collected samples from the mesial and distal surfaces of teeth in 3 groups of young persons. In a control group, which had not undergone orthodontic treatment, a major band of hyaluronic acid (HA) and a minor band of chondroitin sulphate (CS) were present. No differences in the mean content of either GAG between the mesial and distal surfaces were detected. From teeth undergoing movement by fixed appliances (active group), a raised mean level of CS was present in GCF from the surface towards which movement was directed. Teeth held passively by an appliance following cessation of active movement (retention group) showed raised levels of CS at mesial and distal surfaces. A heparan sulphate-like GAG was commonly present in this group only. No significant increase in the levels of HA were detected at the mesial and distal surfaces of either the active or the retention groups, despite increased GCF flow rates unassociated with more severe gingival inflammation. The GAG composition of GCF, particularly CS, appears to reflect changes occurring in the deeper periodontal tissues of alveolar bone and periodontal ligament during orthodontic treatment.     

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.     

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.     

MicroRNA-34 expression in gingival crevicular fluid correlated with orthodontic tooth movement

ObjectivesTo explore the expression of miR-34a and its effect on expression of matrix metalloproteinases (MMPs) during orthodontic tooth movement (OTM).Materials and MethodsTwenty patients, age 12–18 years old, who underwent orthodontic treatment were enrolled. The expression of miR-34a and MMPs (MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, and MMP-14) were detected in gingival crevicular fluid by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction at different time points. The miR-34a mimics or inhibitors were transfected into human periodontal ligament (hPDL) cells, and the MMP expression was measured by ELISA.ResultsThe miR-34 expression in GCF on both the tension and pressure sides after orthodontic treatment were significantly downregulated, while the levels of MMPs were significantly upregulated compared with baseline level. The levels of miR-34 and MMPs returned to baseline level 3 months after orthodontic treatment. The expression of miR-34 was negatively correlated with the expression of MMP-2, MMP-9, and MMP-14. After transfection with miR-34, the MMP-2, MMP-9, and MMP-14 expression by hPDL cells were significantly downregulated compared with miR-control and miR-34 inhibitor.ConclusionsDownregulated miR-34 expression was positively correlated with MMP-2, MMP-9, and MMP-14 expression. The miR-34a transfection into hPDL cells inhibited expression of MMPs. The results suggest that miR-34a is involved in expression of MMPs during OTM.     

Cytokines in crevicular fluid and orthodontic tooth movement

This review aimed to evaluate studies on cytokines in the gingival crevicular fluid (GCF) during orthodontic treatment, summarizing the regulation patterns of the most commonly studied cytokines and exploring their clinical implications. To achieve this, a number of key databases were searched using MESH terms and free text terms. An additional search was made by reference tracking. The procedures suggested by the QUOROM statement were followed. Data from the included studies were extracted into orthodontic mechanics, GCF sampling/handling methods, and cytokine measurements. From the 85 relevant studies identified, 23 studies could be included. Common drawbacks consisted mainly of inadequacies in the study design (e.g. short duration and small number of study subjects). The most consistent result was a peak of cytokine levels at 24 h. Associations existed between prostaglandin E₂ (PGE₂) and interleukin-1β (IL-1β) and pain, velocity of tooth movement, and treatment mechanics. Interleukin-1β and PGE₂ showed different patterns of up-regulation, with IL-1β being more responsive to mechanical stress and PGE₂ more responsive to synergistic regulation of IL-1β and mechanical force. The results might be taken to support, at the cellular level, the use of light continuous forces for orthodontic treatment.     

Identification of dentine sialoprotein in gingival crevicular fluid during physiological root resorption and orthodontic tooth movement

Root resorption is an unwanted effect of orthodontic tooth movement. Analysis of dentine proteins in gingival crevicular fluid (GCF) is a potentially safer method of quantifying root resorption compared with conventional radiographic methods. This study aimed to identify and quantify the dentine-specific matrix protein, dentine sialoprotein (DSP), released into GCF during physiological root resorption and orthodontic tooth movement. GCF was collected using micropipettes from 50 second primary molar sites undergoing physiological root resorption in 9- to 14-year olds [coronal group (Rc) with advanced resorption (n = 33) and apical group (Ra) with minimal resorption (n = 17)] and 20 subjects aged 8-14 years with erupted mandibular second premolars (control group). In addition, GCF was collected from 20 patients undergoing treatment with fixed appliances at two time points, immediately prior to orthodontic intervention (T0) and 12 weeks following commencement of fixed appliance therapy (T1). GCF samples were analysed for DSP using an immunoassay and levels semi-quantified using image analysis. To determine differences between the means of the various experimental and control groups, data based on the relative optical density volumes, were statistically analysed using a parametric t-test. DSP was raised in sites that were undergoing physiological resorption compared with the non-resorbing controls (P < 0.05). Notably, DSP was detected in some control samples. There was no difference in DSP levels for the Rc or Ra groups. DSP was also raised in GCF samples of teeth at 12 weeks following commencement of fixed appliance therapy (P < 0.001). The results highlight the potential for measuring DSP in GCF as a biomarker to monitor root resorption. Dentine is likely to be the major source for DSP in GCF, although alternative origins of bone and cementum are possible.     

The in vivo levels of matrix metalloproteinase-1 and -8 in gingival crevicular fluid during initial orthodontic tooth movement

Orthodontic force induces biochemical responses in the periodontal ligament (PDL), but the matrix metalloproteinase (MMP)-dependent molecular mechanisms in orthodontically induced periodontal remodeling have remained unclear. Previous studies indicate that mechanical stress induces MMP-1 production in human PDL cells in vitro. We tested the hypothesis whether the in vivo levels, molecular forms, and degree of activation of MMP-1 and MMP-8 in gingival crevicular fluid (GCF) reflect an early stage of orthodontic tooth movement. Molecular forms of MMP-1 and MMP-8 were analyzed by Western blot, and MMP-8 levels by quantitative immunofluorometric assay (IFMA). The results showed that GCF MMP-8 levels for orthodontically treated teeth were significantly higher at 4-8 hrs after force application than before activation, and when compared with the control teeth (p < 0.05). Analysis of our data indicates that the cells within the periodontium are up-regulated to produce MMP-8, and the increased expression and activation of GCF MMP-8 reflect enhanced periodontal remodeling induced by orthodontic force.     

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.     

正畸牙齿龈沟液中白介素-17含量的研究

目的检测正畸牙加力前、加力后压力侧和张力侧龈沟液中白介素-17（IL-17）的含量。方法选择拔除4个第一双尖牙拉尖牙远移正畸患者20例,用滤纸条法收集加力前、加力1个月后上颌尖牙压力侧及张力侧龈沟液,采用双抗夹心酶联免疫吸附法（ELISA）检测龈沟液中IL-17的浓度。结果加力前、加力后压力侧和张力侧龈沟液中IL-17的浓度有显著性差异,压力侧龈沟液中IL-17的浓度明显高于加力前和张力侧（P〈0.05）。结论正畸力作用下,压力侧龈沟液中IL-17表达高于加力前和张力侧。IL-17可能参与了正畸力诱导的破骨细胞分化和牙槽骨吸收的过程。     

Age effect on orthodontic tooth movement rate and the composition of gingival crevicular fluid

Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie - To evaluate and form a&nbsp;comprehensive understanding of the effect of patient age on bone remodeling and...     

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.     

The effects of orthodontic tooth movement on the glycosaminoglycan components of gingival crevicular fluid

Abstract In this study, gingival crevicular fluid (GCF) was collected from around a canine tooth, in children, before and during orthodontic tooth movement. The aim was to identify and quantify the glycosaminoglycan (GAG) components of GCF and relate them to tooth movement, gingival inflammation, plaque accumulation, pocket probing depth and GCF volume recorded at the site of sampling. GAG in GCF samples, collected for a 15-min period into microcapillary tubes, were separated electrophoretically, stained with Alcian blue and quantified using a laser densitometer. 2 GAG components of hyaluronic acid (HA) and chondroitin sulphate (CS) were identified. The increase in GCF volume during orthodontic tooth movement was only partly due to increased gingival inflammation, GAG levels varied with different types of orthodontic tooth movement. In GCF, levels of CS, in particular, may reflect the changes in the deeper periodontal tissues which could be monitored during orthodontic tooth movements.     

正畸移动牙龈沟液中IL-1βICAM-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-1和可溶性细胞粘附分子-1(sICAM-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-1夂蛃ICAM-1的含量.结果 实验组在受力后龈沟液中IL-1夂蛃ICAM-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-1夂蛃ICAM-1基本维持在基线.第2、3天实验组GCF中IL-1獾暮亢偷、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-1夂蛃ICAM-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.