Tumor Necrosis Factor–α Levels during Two Different Canine Distalization Techniques

Assessment of salivary tumor necrosis factor-alpha level in the initial stages of treatment with fixed appliances and clear aligners

OBJECTIVES

To assess and compare the tumor necrosis factor-alpha (TNF-α) levels in saliva samples during the initial stages of orthodontic treatment with fixed orthodontic appliances (FAs) and clear aligners (CAs).

MATERIALS AND METHODS

This longitudinal study comprised 40 patients (22 males, 18 females, mean age 22 ± 7 years) who were categorized into two equal-sized groups. Group A comprised 20 patients treated with FA, and Group B comprised 20 patients treated with CA. Unstimulated saliva was collected before the intiation of treatment and then collected again after the placement of the FA/CA at 24 hrs, 7th day, and on the 21st day in both groups. TNF-α levels were determined through ELISA.

STATISTICAL ANALYSIS

The data were subjected to statistical analysis. For intragroup comparison of TNF-α at different time points, the Wilcoxon matched-pairs signed-rank test was used, and for intergroup comparison of FAs and CAs at different time points, the Mann-Whitney U test was used.

RESULTS

TNF-α levels in the saliva increased significantly at 24 hours, followed by a decline on the 7th day and 21st day in both groups. Changes in TNF-α levels were significantly higher in the FA group than those in the CA group at different time points.

CONCLUSION

This study showed that the salivary TNF-α levels increased significantly during the initial stages of FA and CA treatment at different time points. The mean salivary TNF-α level in both FA and CA groups increased significantly at 24 hours, followed by a decline on the 7th day and then on the 21st day. There was a significant difference between the FA and CA treatment, where the CAs showed a significantly low level of TNF-α in saliva at different intervals of time when compared to the FAs.

Impact of Low-Level Laser Therapy on Orthodontic Tooth Movement and Various Cytokines in Gingival Crevicular Fluid: A Split-Mouth Randomized Study

BACKGROUND AND OBJECTIVES

A few investigations have detailed the influence of low-level laser therapy (LLLT) on orthodontic tooth movement (OTM), with varying results. The objectives of this study were twofold: to assess the impact of LLLT on OTM and various cytokine levels in gingival crevicular fluid and to contrast the pain levels experienced by patients receiving orthodontic treatment with and without LLLT.

MATERIALS AND METHODS

This split-mouth randomized controlled prospective study comprised 40 patients with an average age of 19.7±2.4 years with Angle Class I malocclusion combined with bimaxillary protrusion who were advised for extraction of the maxillary first premolar and bilateral canine distalization. The control-side canine was distalized solely by the coil spring. On the test arm, a low-level gallium-aluminum-arsenide semiconductor diode laser operating at 980 nm and 100 mW with a continuous-wave energy of 8 J/cm2 was used. The canine distalization on either side was measured with a digital caliper following the first premolar extraction (TO), one month after treatment (TOTM1), two months later (TOTM2), and three months later (TOTM3). The gingival index and the level of various cytokines were determined by an enzyme-linked immunosorbent assay at the beginning of the study, on the third and seventh days, and at four, eight, and 12 weeks following the canine distalization. The intra-group and inter-group comparisons were carried out using one-way analysis of variance (ANOVA) and t-tests, respectively, at a 5% significance level.

RESULTS

The results show a highly statistically significant difference in the extent of canine distalization in the test group (TOTM1=2.92±0.44; TOTM2=1.04±0.1; TOTM3​=0.62±0.21 mm) in contrast to the control group (TOTM1=3.23±0.8; TOTM2=2.65±0.2; TOTM3​​​​=2.11±0.24 mm) (p<0.01). After three months of canine distalization, the laser and control group had 34 and 27 patients with mild gingivitis, respectively. Interleukin-1β and interleukin-6 concentrations surged with values of 0.74±0.13 and 0.049±0.001 pg/g at seven days following treatment in the laser group, respectively. The difference in tumor necrosis factor concentration between the groups was shown to be highly statistically significant in all treatment phases (p<0.001). The differences in the epidermal growth factor and microglobulin levels were found to be statistically significant within both groups from T0 to T5. The average visual analog scale (VAS) scores at several subsequent evaluations of the laser and control groups were found to be highly statistically significant.

CONCLUSION

The findings imply that when the periodontal microenvironment is stimulated by orthodontic force, several paramount cytokines are released, triggering an ordered sequence of biological processes that appear to expedite OTM with reduced associated pain.

Comparison of cytokine level changes in gingival crevicular fluid between the aligner and pendulum appliance during early molar distalization : A single-center, prospective, observational study

PURPOSE

There is currently a lack of evidence pertaining to gingival crevicular fluid cytokine levels in patients treated with the pendulum appliance. This study aimed to compare changes in cytokine secretion levels in gingival crevicular fluid (GFC) between the aligner and pendulum appliance in patients undergoing molar distalization.

METHODS

GFC samples were collected from 28 participants with asymmetrical dental class II malocclusion who were undergoing molar distalization using aligners or pendulum appliances. An enzyme-linked immunosorbent assay was used to detect cytokine secretion levels during asymmetrical molar distalization for up to 14 days. Periodontal health indices and tooth movements were also assessed.

RESULTS

No significant difference was found for the distalization distance between the two appliances. The Silness and Loe Plaque Index and Lobene Modified Gingival Index increased in the pendulum group but not in the aligner group at 14 days. Interleukin-1β and tumor necrosis factor‑α were upregulated in both groups. In the pendulum group, receptor activator of nuclear factor kappa‑Β ligand and osteoprotegerin secretion levels were significantly upregulated and downregulated, respectively; smaller changes in these two cytokines were observed in the aligner group.

CONCLUSIONS

Pendulum appliances exert stronger forces than aligners, which cause more changes in the secretion of inflammatory mediators in young patients.

Sympathetic nervous system contributes to orthodontic tooth movement by central neural regulation from hypothalamus

Orthodontic tooth movement (OTM) is a specific treatment of malocclusion, whose regulation mechanism is still not clear. This study aimed to reveal the relationship between the sympathetic nervous system (SNS) and OTM through the construction of an OTM rat model through the utilization of orthodontic nickeltitanium coiled springs. The results indicated that the stimulation of SNS by dopamine significantly promote the OTM process represented by the much larger distance between the first and second molar compared with mere exertion of orthodontic force. Superior cervical ganglionectomy (SCGx) can alleviate this promotion effect, further proving the role of SNS in the process of OTM. Subsequently, the ability of orthodontic force to stimulate the center of the SNS was visualized by the tyrosin hydroxylase (TH) staining of neurons in ventromedial hypothalamic nucleus (VMH) and arcuate nucleus (ARC) of the hypothalamus, as well as the up-regulated expression of norepinephrine in local alveolar bone. Moreover, we also elucidated that the stimulation of SNS can promote osteoclast differentiation in periodontal ligament cells (PDLCs) and bone marrow-derived cells (BMCs) through regulation of receptor activator of nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG) system, thus promoting the OTM process. In conclusion, this study provided the first evidence for the involvement of the hypothalamus in the promotion effect of SNS on OTM. This work could provide a novel theoretical and experimental basis for further understanding of the molecular mechanism of OTM.

Elevated levels of Interleukin (IL)-1β, IL-6, tumor necrosis factor-α, epidermal growth factor, and β2-microglobulin levels in gingival crevicular fluid during human Orthodontic tooth movement (OTM)

AIM

The aim of this study was to identify and quantify the various cytokines in human gingival crevicular fluid (GCF), and to investigate the changes in their levels during orthodontic tooth movement (OTM).

MATERIALS AND METHODS

A statistically significant no. of subjects (n = 10 and mean age = 15.6 years) were included in the study. A maxillary cuspid of each subject having one treatment for distal orthodontic tooth movement served as the experimental tooth, whereas the contralateral cuspids were used as controls. Gingival crevicular fluid (GCF) around the experimental and the two control teeth was collected from each subject immediately before activation, and at 1, 24, and 168 hours after the initiation of tooth movement.

RESULT

ELISAs were used to determine cytokine levels. The concentrations of interleukin (IL)-1lβ, IL-6, tumor necrosis factor-α, epidermal growth factor, and β2-microglobulin were significantly higher in the experimental group than in the controls at 24 hr after the experiment was initiated. All the cytokines remained at baseline levels throughout the experiment for the control groups.

CONCLUSION

Since all cytokines in GCF play an important role in the bone remodelling processes in vivo, the present results indicate that the changes in cytokines in GCF are associated with OTM.

Expression of cytokines in gingival crevicular fluid associated with tooth movement induced by aligners: a pilot study

Introduction:

The search for more aesthetic and comfortable orthodontic devices has led to an increase in the use of clear aligners.

Objective:

To increase knowledge on biological mechanisms of orthodontic tooth movement using Invisalign aligners.

Methods:

This study included 11 patients with a mean age of 23.6 ± 4.8 years. Cases planning included alignment and leveling of lower incisors using Invisalign aligners. Gingival crevicular fluid samples were collected from the lower incisors on the day of delivery of aligner number 1 (T0) and after 1 (T24h), 7 (T7d), and 21 (T21d) days. During the observation period of the study, the patients used only the aligner number 1. Levels of nine cytokines were quantified using Luminex’s multi-analysis technology. Non-parametric tests were used for comparisons between cytokine expression levels over time.

Results:

Cytokine expression levels remained constant after 21 days of orthodontic activation, except those of MIP-1β, which presented a statistical difference between T24h and T21d with a decrease in the concentration levels. IL-8, GM-CSF, IL-1β, MIP-1β, and TNF-α showed the highest concentrations over time.

Conclusions:

The different behavior in the levels of the investigated cytokines indicates a role of these biomarkers in the tissue remodeling induced by Invisalign.

Assessment of tumor necrosis factor alpha (TNFα) and interleukin 6 level in gingival crevicular fluid during orthodontic tooth movement: a randomized split-mouth clinical trial

Background

Orthodontic tooth movement (OTM) is based on induction of periodontal tissue remodeling. Mechanical tooth stimulation results in the release of pro-inflammatory mediators. These mediators cause bone resorption and deposition at the pressure and tension sites and play a role in OTM. Thus, assessment of chemical biomarkers can help determine the exact amount of load and its duration of application required for each tooth and select the most efficient treatment plan with minimal complications.

Objective

This study aimed to determine the level of tumor necrosis factor alpha (TNFα) and interleukin 6 (IL-6) in gingival crevicular fluid (GCF) during OTM.

Methods

This randomized split-mouth clinical trial (parallel) was performed on 10 patients who were presenting to the Orthodontic Department of Qazvin University of Medical Sciences from November 2015 to June 2016. A canine tooth was randomly selected as the study group and subjected to distalization force while the contralateral canine tooth served as control. Using paper strip, GCF was collected from the study and control teeth prior to orthodontic force application (T0), one hour after (T1) and 28 days after force application (T2), then the level of TNFα and IL-6 was measured using ELISA. Data were analyzed using SPSS version 20 via Friedman and Wilcoxon test, and considering the significance level at p<0.05.

Results

The level of TNFα (p=0.0799) and IL-6 (p=0.678) at both sides of study teeth was higher than both side of control teeth at T1. Also, the level of IL-6 (p=0.515) and TNFα (p=0.508) were higher at the tension side compared to the pressure side; but the difference was not statistically significant.

Conclusion

Due to the free circulation of GCF in gingival sulcus, the level of mediators in the GCF collected from the mesial and distal areas alone cannot serve as a suitable index for assessment of activity at the tension and pressure sites.

Trial registration

The trial was registered at the Iranian Registry of Clinical Trials with the IRCT ID: IRCT2017030632903N2.

Funding

The present study was supported by a grant from the Research Council, Qazvin University of Medical Sciences, Qazvin, Iran (thesis no.: 40).

Effect of orthodontic force on expression levels of ten cytokines in gingival crevicular fluid

Various types of inflammatory mediators are involved in the cascade of biological events behind tissue remodeling allowing orthodontic tooth movement. This split-mouth longitudinal study aimed to evaluate the gingival crevicular fluid (GCF) levels of ten cytokines, IL-6, IL-8, IL-10, IL-13, IL-17, IFN-γ, GM-CSF, MCP-1, MIP-1β and TNF-α, during initial orthodontic treatment. The sample comprised 15 healthy patients (9 males and 6 females, 13.9±2.5 years). The lower (test) incisors were moved using fixed appliance carrying a 0.014-inch nickel titanium wire, whereas the upper (control) incisors were bonded without any force. The GCF was collected from the test and control teeth before fixed appliance mounting (baseline) and after 1, 7 and 21days. In 6 sites per tooth, from canine to canine, periodontal conditions were defined as the percentage of sites with visible plaque and bleeding on probing. The total GCF cytokines levels were quantified using multianalysis Luminex technology. Throughout the experimental term, and for both test and control teeth, the mean percentage of sites with visible plaque and bleeding on probing were generally below 25% and 15%, respectively, although variability was also seen. In the test teeth, the GCF levels of all the cytokines remained constant throughout the experimental term. On the contrary, significant reductions were seen in the control teeth for each cytokine. Moreover, significantly greater levels of IL-6, GM-CSF, MCP-1 and TNFα were seen in the test teeth as compared to the control teeth at 7days. The reasons for the differential behavior in the levels of all the investigated cytokines between the test and control teeth may be related to the presence of orthodontic forces and/or subclinical tissue inflammation. Further investigation is needed to elucidate potential roles for these biomarkers in the tissue remodeling incident to orthodontic tooth movement.

Comparative evaluation of pentraxin 3 levels in GCF during canine retraction with active tieback and NiTi coil spring: An in vivo study

Objectives:

To compare the levels of pentraxin 3 (PTX-3) in gingival crevicular fluid (GCF) in patients undergoing orthodontic canine retraction with active tieback and nickel titanium (NiTi) coil spring.

Materials and Methods:

Fifteen patients of the age group 15–25 years with first premolar extraction undergoing canine retraction were selected. One month after placement of 0.019” × 0.025” stainless steel wire, canine retraction was started with active tieback (150 g force) on upper right quadrant and NiTi coil spring (150 g force) on upper left quadrant. GCF samples were collected 1 h before commencement of canine retraction and thereafter at intervals of 1 h, 1 day, 1 week, and 2 weeks after application of force. The collected GCF was eluted from the microcapillary pipette in 100 μl phosphate-buffered saline (pH 5–7.2). The samples were analyzed for PTX-3 levels by the ELISA technique.

Results:

The mean levels of PTX-3 at 1 h before canine retraction (baseline) was 1.30 ± 0.22 ng/ml and at 1 h 1.66 ± 0.33 ng/ml, 1 day 2.65 ± 0.09 ng/ml, 1 week 1.96 ± 0.15 ng/ml, and 2 weeks 1.37 ± 0.18 ng/ml in active tieback group. The mean levels of PTX-3 at 1 h before canine retraction was 1.32 ± 0.30 ng/ml, and at 1 h 1.71 ± 0.39 ng/ml, 1 day 2.78 ± 0.12 ng/ml, 1 week 2.52 ± 0.18 ng/ml, and 2 weeks 2.12 ± 0.17 ng/ml in NiTi coil spring group. A significant difference of P < 0.001 was found in PTX-3 levels in GCF during canine retraction between active tieback and NiTi coil spring at 1 day, 1 week, and 2 weeks.

Conclusion:

The results showed that PTX-3 levels increased from 1 h after application of orthodontic force and reached peak at 1 day, followed by a gradual decrease at 1 week and 2 weeks in both active tie back and NiTi coil spring groups.

Estimation of alkaline phosphatase in the gingival crevicular fluid during orthodontic tooth movement in premolar extraction cases to predict therapeutic progression

OBJECTIVES

The objective was to estimate the level of alkaline phosphatase (ALP) in gingival crevicular fluid (GCF) during en-masse retraction stage of orthodontic tooth movement.

MATERIALS AND METHODS

10 patients in the age group of 15-20 years participated in this study. GCF was sampled from the distal surface of the canine and mesial surface of the second premolar on day 0, 1, 7, 14, 21, and 28 postorthodontic treatment.

RESULTS

A marked fall in the level of ALP was evident following force application. A progressive decreasing trend in ALP activity on both distal aspect of canine and mesial aspect of the second premolar was observed. The fall in ALP was more on distal aspect canine when compared to the mesial aspect of the second premolar.

CONCLUSIONS

Measure of ALP activity in GCF could be an indicator of the biochemical and cellular alterations in bone turnover and hence rate the amount of tooth movement following orthodontic force application.

Biomarkers of Orthodontic Tooth Movement in Gingival Crevicular Fluid: A Systematic Review

BACKGROUND

The analysis of gingival crevicular fluid (GCF) may be an acceptable way to examine the ongoing biochemical processes associated with bone turnover during orthodontic tooth movement. If it is possible to biologically monitor and predict the outcome of orthodontic forces, then the management of appliances could be based on individual tissue responses, and the effectiveness of the treatment could be improved.

METHODOLOGY

A literature search was carried out in major databases, such as medline, EMBASE, cochrane library, web of science, google scholar and scopus for relevant studies. Publications in English between 2000 and 2014 which estimated GCF markers as indicators of orthodontic tooth movement were included.

RESULTS

The list of biomarkers available to date was compiled and presented in table format. Each biomarker is discussed separately based on the available evidence.

CONCLUSION

Several sensitive GCF markers are available to detect the biomechanical changes occurring during orthodontic tooth movement. Further focused research might help to analyze the sensitivity and reliability of these indicators, which in turn can lead to the development of chairside tests to assess the outcome of orthodontic therapy.

Changes of tumor necrosis factor-α, interleukin-10, and tartrate-resistant acid phosphatase5b in the crevicular fluid in relation to orthodontic movement

The aim of this study was to determine gingival crevicular fluid (GCF) expressions of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), and tartrate-resistant acid phosphatase (TRAP) 5b in the mechanism of orthodontic tooth movement. Nine adolescents requiring canine distalization participated in the study. A canine undergoing distal movement served as the test tooth, and the contra-lateral canine served as the control. The clinical parameters were recorded and GCF samples were collected from the mesial and distal gingival crevices of teeth at baseline, 1 h, 24 h, 7 days, and 28 days following force application. GCF samples were analyzed using ELISA. The data were analyzed using three-way repeated measures analysis of variance. TNF-α and TRAP5b levels in distal and mesial sites of the test teeth were significantly higher than that at both sites of the controls. When compared with baseline values, increase was prominent at 1 h and 24 h. The IL-10 concentration decreased during experimental period at both sites of the control and test teeth. The results demonstrated that orthodontic forces evoke changes in the levels of TNF-α, IL-10, and TRAP5b during the initial stages of force application. The changes in local host response in periodontal tissues may be one of the triggers in regulating alveolar bone resorption during orthodontic tooth movement.

Effect of orthodontic forces on cytokine and receptor levels in gingival crevicular fluid: a systematic review

This systematic review aimed to generate evidence on role of potent markers of inflammation [cytokines, chemokines, their associated receptors and antagonists] following the application of orthodontic forces. Subsequent to registration with PROSPERO, literature search followed a predetermined search strategy to key databases along with hand search (HS). Seventy-seven articles from PubMed (P), 637 from Scopus (S), 51 from Embase (E), and 3 from hand search (HS) were identified. A total of 39 articles were shortlisted that met strict inclusion and exclusion criteria and quality assessment. Each study was evaluated for participant characteristics, study design, oral hygiene regimen, and gingival crevicular fluid (GCF) handling. Among these studies, biomarkers in the order of frequency were interleukin (IL)-1β (N = 21), tumor necrosis factor (TNF)-α (N = 10), IL-8,IL-6(N=8), receptor activator of nuclear factor kappa-B ligand (RANKL) (N = 7), monocyte chemoattractant protein (MCP)-1 (N = 3), IL-2 (N=4), IL-4, IL-10, RANTES (N = 2), IL-1, IL-5, IL-1α, IP-10, osteopontin (OPN) (N = 1) and receptors and their antagonists in the order of osteoprotegerin (OPG) (N = 8), IL-1RA (N = 5), and RANK (N = 1). Results revealed an immediate release of inflammatory bone-resorptive mediators, IL-1β and TNF-α, where IL-1β increased as early as 1 min to 1 h reaching peak at 24 h while TNF-α increased at 1 h or 1 day. This was accompanied by a fall in bone-protective mediator (OPG) levels at 1 h and 24 h after orthodontic force application. Continuous forces were accompanied by a decrease in mediator levels after attaining peak levels (most commonly at 24 h) while repeated activations in interrupted force upregulated their secretion. Significant correlations of IL-1β levels with pain intensity, rate of orthodontic tooth movement (OTM) and of activity index (AI) (IL-1β/IL-1RA) with velocity of tooth movement and growth status of individuals have also been deduced. A greater AI and RANKL/OPG ratio was seen in juveniles as compared to adults or non-growers that were associated with faster rate of OTM in juveniles. None of the studies addressed the effect of estrous cycle in female subjects. Lack of homogeneity in several parameters calls for a better controlled research on the biology of OTM.

Myeloperoxidase enzymatic activity is increased in patients with different levels of dental crowding after initial orthodontic activation

INTRODUCTION

Orthodontic tooth movement implies application of forces that generate an inflammatory process. The myeloperoxidase (MPO) enzyme is found inside neutrophil granules. MPO activity indirectly reflects the level of inflammation. The aim of this study was to measure MPO activity in gingival crevicular fluid (GCF) and whole saliva in orthodontic patients with different levels of dental crowding at the alignment phase of orthodontic treatment with the same archwires.

METHODS

Twenty patients were classified according to the irregularity index into 2 groups: severe and minimum crowding (10 in each group). MPO activity was evaluated in GCF and saliva at 0 and 2 hours, and 7 and 14 days after the orthodontic appliances were activated. MPO activity was measured using the modified Bradley-Bozeman technique.

RESULTS

In both groups, the maximum activity was at 2 hours (P <0.05) after activation. MPO activity remained elevated until day 7, and values similar to baseline were found at day 14 in the GCF and saliva samples. Enzymatic activity did not show statistical differences between the groups.

CONCLUSIONS

The amount of dental crowding does not seem to influence MPO activity, which showed similar patterns in GCF and saliva, but the values in GCF reflected the inflammatory changes more accurately than did the values in saliva. The quantification of MPO activity is a useful biologic marker as an indirect measurement of inflammation generated with tooth movement independent of the amount of crowding.

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.

Understanding the advances in biology of orthodontic tooth movement for improved ortho-perio interdisciplinary approach

This article provides an insight on detailed current advances in molecular understandings of periodontal ligament cells and the influence of orthodontic force on them in the light of recent advances in molecular and genetic sciences. It sequentially unfolds the cellular events beginning from the mechanical force initiated events of cellular responses to bone remodeling. It also highlights the risks and limitations of orthodontic treatment in certain periodontal conditions, the important areas of team work, orthodontic expectations from periodontal treatment and the possibility of much more future combined research to improve the best possible periodontal health and esthetic outcome of the patient.

Evaluation of oxidative stress biomarkers in patients with fixed orthodontic appliances

AIM

The aim of this study was to examine the changes in the levels of interleukine-1 beta (IL-1 β ), tumor necrosis factor alpha (TNF- α ), malondialdehyde (MDA), nitric oxide (NO), and 8-hydroxydeoxyguanosine (8-OHdG) in saliva and IL-1 β , TNF- α , and NO in gingival crevicular fluid (GCF) samples of patients with fixed orthodontic appliances.

MATERIAL AND METHOD

The subject population consisted of 50 volunteers who were in need of orthodontic treatment with fixed orthodontic appliances. GCF and saliva samples were obtained from all individuals before treatment, at 1st month of treatment and at 6th month of treatment. Periodontal clinical parameters were measured. Samples were investigated to detect IL-1 β , TNF- α , and 8-OHdG levels using ELISA method and NO and MDA levels using spectrophotometric method.

RESULTS

Since IL-1 β level detected in GCF at the 6th month of orthodontic treatment is statistically significant according to baseline (P < 0.05), all other biochemical parameters detected both in saliva and in GCF did not show any significant change at any measurement periods.

CONCLUSION

Orthodontic tooth movement and orthodontic materials used in orthodontic treatment do not lead to a change above the physiological limits that is suggestive of oxidative damage in both GCF and saliva.

Pentraxin-3 levels in gingival crevicular fluid during orthodontic tooth movement in young and adult patients

OBJECTIVES

To measure the levels of pentraxin-3 (PTX-3) in gingival crevicular fluid (GCF) in orthodontic young and adult patients in the first 2 weeks after the orthodontic appliance to determine whether those changes occur during orthodontic treatment and if those values could be the expression of an inflammatory state.

MATERIALS AND METHODS

GCF samples were collected with paper strips from 16 orthodontic young patients and 13 orthodontic adult patients from an upper canine requiring distalization as a test tooth. A contralateral canine was used as a control tooth. The absorbed volume was eluted in 100 µL phosphate-buffered saline (pH  =  7.2). PTX-3 levels in GCF were determined using a commercial enzyme-linked immunosorbent assay kit, and the results were expressed in ng/mL.

RESULTS

The results showed an increase of GCF levels of PTX-3 from 1 hour before the orthodontic appliance to a maximum at 24 hours, followed by a decrease in both groups of adult and young patients.

CONCLUSIONS

The results suggest PTX-3 involvement in periodontal orthodontic remodeling and the aseptic inflammation induced by the orthodontic forces.

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.

Myeloperoxidase activity is increased in gingival crevicular fluid and whole saliva after fixed orthodontic appliance activation

INTRODUCTION

Orthodontic tooth movement uses mechanical forces that result in inflammation in the first days. Myeloperoxidase (MPO) is an enzyme found in polymorphonuclear neutrophil (PMN) granules, and it is used to estimate the number of PMN granules in tissues. So far, MPO has not been used to study the inflammatory alterations after the application of orthodontic tooth movement forces. The aim of this study was to determine MPO activity in the gingival crevicular fluid (GCF) and saliva (whole stimulated saliva) of orthodontic patients at different time points after fixed appliance activation.

METHODS

MPO was determined in the GCF and collected by means of periopaper from the saliva of 14 patients with orthodontic fixed appliances. GCF and saliva samples were collected at baseline, 2 hours, and 7 and 14 days after application of the orthodontic force.

RESULTS

Mean MPO activity was increased in both the GCF and saliva of orthodontic patients at 2 hours after appliance activation (P <0.02 for all comparisons). At 2 hours, PMN infiltration into the periodontal ligament from the orthodontic force probably results in the increased MPO level observed at this time point.

CONCLUSIONS

MPO might be a good marker to assess inflammation in orthodontic movement; it deserves further studies in orthodontic therapy.

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 E(2) (PGE(2)) and interleukin-1beta (IL-1beta) and pain, velocity of tooth movement, and treatment mechanics. Interleukin-1beta and PGE(2) showed different patterns of up-regulation, with IL-1beta being more responsive to mechanical stress and PGE(2) more responsive to synergistic regulation of IL-1beta and mechanical force. The results might be taken to support, at the cellular level, the use of light continuous forces for orthodontic treatment.