Assessment of the rate of premolar extraction space closure in the maxillary arch with the AcceleDent Aura appliance vs no appliance in adolescents: A single-blind randomized clinical trial

Effective mechanical vibration frequency in canine tooth movement acceleration: a systematic review and network meta-analysis of randomized controlled trial studies

OBJECTIVE

This study aims to evaluate the effectiveness of various supplementary vibrational frequencies with orthodontic force on the rate of canine movement.

MATERIALS AND METHODS

A literature search was conducted in PubMed, Embase, Cochrane, Scopus, ClinicalTrials.gov, and Google Scholar, with the final search on February 17, 2025. Randomized controlled trials (RCTs) involving participants undergoing orthodontic treatment with upper first premolar extraction, assessed the effect of different vibration frequencies on canine movement rate were included. Study quality was assessed using the Risk of Bias (RoB) 2. A random-effects model (DerSimonian and Laird method) for pairwise meta-analysis (PMA) and a frequentist-based network meta-analysis (NMA) estimated relative effects, with mean difference (MD) and 95% confidence interval (CI) calculated for all comparisons. The certainty of evidence was assessed using the Confidence in Network Meta-Analysis tool.

RESULTS

Ten RCTs examined the effects of five vibration frequencies. The RoB ranged from low to high. The PMA found vibrations significantly increased tooth movement (MD = 0.084 mm, 95% CI [0.004, 0.164]). Conversely, NMA showed no significant differences across all comparisons. The Surface Under the Cumulative Ranking Curve ranked 125 Hz as the most effective, followed by 100, 60, 30, and 0 Hz. The confidence in evidence ranged from low to moderate.

CONCLUSIONS

The use of supplementary vibration in conjunction with orthodontic force statistically effectively accelerates tooth movement, with higher frequencies showing a tendency to yield better acceleration results.

CLINICAL RELEVANCE

While vibration therapy demonstrated a statistically significant effect on canine movement, the magnitude of this effect was not sufficient to be considered clinically significant for orthodontic treatment. Further research is required to optimize the effectiveness.

Selective modulation of the bone remodeling regulatory system through orthodontic tooth movement-a review

Little is known about how tissues mediate the ability to selectively form or resorb bone, as required during orthodontic tooth movement (OTM), facial growth, continued tooth eruption and for healing after fractures, maxillofacial surgical repositioning or implant dentistry. OTM has the unique ability to selectively cause apposition, resorption or a combination of both at the alveolar periosteal surface and therefore, provides an optimal process to study the regulation of bone physiology at a tissue level. Our aim was to elucidate the mechanisms and signaling pathways of the bone remodeling regulatory system (BRRS) as well as to investigate its clinical applications in osteoporosis treatment, orthopedic surgery, fracture management and orthodontic treatment. OTM is restricted to a specific range in which the BRRS permits remodeling; however, surpassing this limit may lead to bone dehiscence. Low-intensity pulsed ultrasound, vibration or photobiomodulation with low-level laser therapy have the potential to modify BRRS with the aim of reducing bone dehiscence and apical root resorption or accelerating OTM. Unloading of bone and periodontal compression promotes resorption via receptor activator of nuclear factor κB-ligand, monocyte chemotactic protein-1, parathyroid hormone-related protein (PTHrP), and suppression of anti-resorptive mediators. Furthermore, proinflammatory cytokines, such as interleukin-1 (IL-1), IL-6, IL-8, tumor necrosis factor-α, and prostaglandins exert a synergistic effect on bone resorption. While proinflammatory cytokines are associated with periodontal sequelae such as bone dehiscence and gingival recessions, they are not essential for OTM. Integrins mediate mechanotransduction by converting extracellular biomechanical signals into cellular responses leading to bone apposition. Active Wnt signaling allows β-catenin to translocate into the nucleus and to stimulate bone formation, consequently converging with integrin-mediated mechanotransductive signals. During OTM, periodontal fibroblasts secrete PTHrP, which inhibits sclerostin secretion in neighboring osteocytes via the PTH/PTHrP type 1 receptor interaction. The ensuing sclerostin-depleted region may enhance stem cell differentiation into osteoblasts and subperiosteal osteoid formation. OTM-mediated BRRS modulation suggests that administering sclerostin-inhibiting antibodies in combination with PTHrP may have a synergistic bone-inductive effect. This approach holds promise for enhancing osseous wound healing, treating osteoporosis, bone grafting and addressing orthodontic treatments that are linked to periodontal complications.

Periodontal response to nonsurgical accelerated orthodontic tooth movement

Tooth movement is a complex process involving the vascularization of the tissues, remodeling of the bone cells, and periodontal ligament fibroblasts under the hormonal and neuronal regulation mechanisms in response to mechanical force application. Therefore, it will inevitably impact periodontal tissues. Prolonged treatment can lead to adverse effects on teeth and periodontal tissues, prompting the development of various methods to reduce the length of orthodontic treatment. These methods are surgical or nonsurgical interventions applied simultaneously within the orthodontic treatment. The main target of nonsurgical approaches is modulating the response of the periodontal tissues to the orthodontic force. They stimulate osteoclasts and osteoclastic bone resorption in a controlled manner to facilitate tooth movement. Among various nonsurgical methods, the most promising clinical results have been achieved with photobiomodulation (PBM) therapy. Clinical data on electric/magnetic stimulation, pharmacologic administrations, and vibration forces indicate the need for further studies to improve their efficiency. This growing field will lead to a paradigm shift as we understand the biological response to these approaches and their adoption in clinical practice. This review will specifically focus on the impact of nonsurgical methods on periodontal tissues, providing a comprehensive understanding of this significant and understudied aspect of orthodontic care.

The effect of chewing gum on the rate of en-masse space closure: A randomised controlled trial

AIM

To evaluate the effect of chewing gum on the rate of space closure, oral hygiene, pain during space closure and appliance breakage in patients undergoing fixed appliance therapy.

DESIGN

A prospective, single-centre, two-arm, parallel, double-blinded randomised controlled trial.

SETTING

Orthodontic unit of a privately funded hospital, Chennai, India.

PARTICIPANTS

In total, 28 participants were randomly allocated into a chewing gum group (CGG) (n = 14) or a control group (CG) (n = 14).

METHODS

Baseline data were collected at the start of retraction (T0), at 4 weeks (T1), 8 weeks (T2) and 12 weeks (T3) after the start of retraction. Rate of space closure, pain, oral hygiene and appliance breakage were assessed at T1, T2 and T3. Data were analysed using an independent t-test with P < 0.05 considered to be statistically significant.

RESULTS

The mean rate of space closure in the CGG was 0.9 ± 0.2 mm/month and 0.8 ± 0.2 mm/month in the CG (mean difference 0.1mm/month ± 0.16; 95% confidence interval -0.055-0.26). In both the groups, oral hygiene became worse between T0 and T3. At T0 and T1, participants in the CGG reported less pain at 24 h and 7 days when compared to the CG (P < 0.05). At T2 and T3, participants in the CGG reported less pain at 0 h, 24 h and 7 days when compared to the CG (P < 0.05). Appliance breakage in both groups was minimal, with an odds ratio of 0.7 (95% CI 0.1-3.8) and was similar (P = 0.66).

CONCLUSION

There was a minimal increase that was clinically not significant in the rate of space closure with chewing gum. Chewing gum ensured better oral hygiene, helped alleviate pain and had no effect on appliance breakage during space closure.

Effect of applying intermittent force with and without vibration on orthodontic tooth movement

PURPOSE

This study aimed to determine whether orthodontic tooth movement could be accelerated by applying an intermittent force protocol. It also examined the effect of applying additional vibrational forces on orthodontic tooth movement and root resorption rates.

METHODS

This study included 24 patients (16 males and 8 females) who underwent orthodontic treatment involving first premolar extraction and distal movement of the canines in the maxilla. A Hycon device (Adenta GmbH, Gilching, Germany) was used for canine distalization in all patients. The patients were randomly divided into two groups: one group received 20 min of vibration per day using the AcceleDent device (OrthoAccel Technologies, Inc., Bellaire, TX, USA), while the other group received no vibration. In addition, a split-mouth design was used: an activation-only force protocol was applied on one side, and an intermittent activation-deactivation-activation (ADA) protocol was applied on the other. The duration required for complete canine tooth distalization on each side was calculated. In addition, the effect of vibration on the orthodontically induced root resorption was examined.

RESULTS

The intermittent ADA protocol significantly accelerated orthodontic tooth movement compared to the activation-only protocol (p < 0.05). The application of additional vibration did not affect the orthodontic tooth movement rate (p > 0.05).

CONCLUSIONS

Using a Hycon device and following an ADA protocol provided significantly faster canine distalization than the activation-only protocol (p < 0.05). This intermittent force method proved very effective in closing the spaces. However, vibration did not significantly affect the orthodontic tooth movement rate (p > 0.05).

The role of photobiomodulation in accelerating bone repair

Bone repair is faced with obstacles such as slow repair rates and limited bone regeneration capacity. Delayed healing even nonunion could occur in bone defects, influencing the life quality of patients severely. Photobiomodulation (PBM) utilizes different light sources to derive beneficial therapeutic effects with the advantage of being non-invasive and painless, providing a promising strategy for accelerating bone repair. In this review, we summarize the parameters, mechanisms, and effects of PBM regulating bone repair, and further conclude the current clinical application of PBM devices in bone repair. The wavelength of 635-980 nm, the output power of 40-100 mW, and the energy density of less than 100 J/cm2 are the most commonly used parameters. New technologies, including needle systems and biocompatible and implantable optical fibers, offer references to realize an efficient and safe strategy for bone repair. Further research is required to establish the reliability of outcomes from in vivo and in vitro studies and to standardize clinical trial protocols.

Effectiveness of low frequency vibration on the rate of canine retraction: a randomized controlled clinical trial

To investigate the effectiveness of AcceleDent Aura vibrating device on the rate of canine retraction. Thirty-two patients requiring extraction of upper first premolars and canine retraction were randomly allocated with a 1:1 ratio into either no-appliance group or the AcceleDent Aura appliance group. Canine retraction was done applying 150gm of retraction force using NiTi coil springs on 16 × 22 stainless steel archwires. The duration of the study was 4 months. Models were collected and digitized directly after extraction of upper first premolars and at monthly intervals during canine retraction for recording the monthly as well as the total distance moved by the canine. Digitized models were superimposed on the initial model and data were statistically analyzed. Anchorage loss, rotation, tipping, torque and root condition were evaluated using cone beam computed tomography imaging. Pain was evaluated by visual analog scale. No patients were dropped-out during this study. There was no statistically significant difference between both groups regarding the total distance travelled by the canine (P = 0.436), as well as the rate of canine retraction per month (P = 0.17). Root condition was the same for the two groups. Regarding the pain level, there was no statistically significant difference between the two groups at day 0 (P = 0.721), after 24 h (P = 0.882), after 72 h (P = 0.378) and after 7 days (P = 0.964). AcceleDent Aura was not able to accelerate orthodontic tooth movement. Pain level couldn't be reduced by vibrational force with an AcceleDent device during orthodontic treatment. Root condition was not affected by the vibrational forces.

Vibrational Force on Accelerating Orthodontic Tooth Movement: A Systematic Review and Meta-Analysis

This study aimed to systematically gather and analyze the current level of evidence for the effectiveness of the vibrational force in accelerating orthodontic tooth movement (OTM). This systematic review was conducted using three electronic databases: Scopus, PubMed, and Google Scholar until March 2022. The search was done through the following journals: European Journal of Orthodontics, American Journal of Orthodontics and Dentofacial Orthopedics, The Angle Orthodontist, Progress in Orthodontics, and Seminars in Orthodontics. Human or animal studies that have evaluated the effect of vibrational force on the rate of OTM were selected. A meta-analysis was performed for the rate of canine movement per month. Database research, elimination of duplicate studies, data extraction, and risk of bias assessment were performed by authors independently and in duplication. A fixed and random-effect meta-analysis was performed to evaluate the effect of vibrational forces. A total of 19 studies (6 animal and 13 human studies) that met the inclusion criteria were included. Meta-analysis was performed based on four human clinical trials. Three out of four studies showed no significant difference in the rate of canine movement between vibrational force and control groups. The limitation of this study was the small sample size and significant heterogeneity among the studies. Although vibrational forces have been shown to accelerate OTM in experimental studies, the results are inconsistent in clinical studies. The inability to apply desired peak load to the targeted teeth may be the main factor in inconsistent clinical outcomes.

Non-surgical adjunctive interventions for accelerating tooth movement in patients undergoing orthodontic treatment

BACKGROUND

Deviation from a normal bite can be defined as malocclusion. Orthodontic treatment takes 20 months on average to correct malocclusion. Accelerating the rate of tooth movement may help to reduce the duration of orthodontic treatment and associated unwanted effects including orthodontically induced inflammatory root resorption (OIIRR), demineralisation and reduced patient motivation and compliance. Several non-surgical adjuncts have been advocated with the aim of accelerating the rate of orthodontic tooth movement (OTM).         OBJECTIVES: To assess the effect of non-surgical adjunctive interventions on the rate of orthodontic tooth movement and the overall duration of treatment.

SEARCH METHODS

An information specialist searched five bibliographic databases up to 6 September 2022 and used additional search methods to identify published, unpublished and ongoing studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of people receiving orthodontic treatment using fixed or removable appliances along with non-surgical adjunctive interventions to accelerate tooth movement. We excluded split-mouth studies and studies that involved people who were treated with orthognathic surgery, or who had cleft lip or palate, or other craniofacial syndromes or deformities.

DATA COLLECTION AND ANALYSIS

Two review authors were responsible for study selection, risk of bias assessment and data extraction; they carried out these tasks independently. Disagreements were resolved by discussion amongst the review team to reach consensus.  MAIN RESULTS: We included 23 studies, none of which were rated as low risk of bias overall. We categorised the included studies as testing light vibrational forces or photobiomodulation, the latter including low level laser therapy and light emitting diode. The studies assessed non-surgical interventions added to fixed or removable orthodontic appliances compared to treatment without the adjunct. A total of 1027 participants (children and adults) were recruited with loss to follow-up ranging from 0% to 27% of the original samples.  Certainty of the evidence For all comparisons and outcomes presented below, the certainty of the evidence is low to very low. Light vibrational forces  Eleven studies assessed how applying light vibrational forces (LVF) affected orthodontic tooth movement (OTM). There was no evidence of a difference between the intervention and control groups for duration of orthodontic treatment (MD -0.61 months, 95% confidence interval (CI) -2.44 to 1.22; 2 studies, 77 participants); total number of orthodontic appliance adjustment visits (MD -0.32 visits, 95% CI -1.69 to 1.05; 2 studies, 77 participants); orthodontic tooth movement during the early alignment stage (reduction of lower incisor irregularity (LII)) at 4-6 weeks (MD 0.12 mm, 95% CI -1.77 to 2.01; 3 studies, 144 participants), or 10-16 weeks (MD -0.18 mm, 95% CI -1.20 to 0.83; 4 studies, 175 participants); rate of canine distalisation (MD -0.01 mm/month, 95% CI -0.20 to 0.18; 2 studies, 40 participants); or rate of OTM during en masse space closure (MD 0.10 mm per month, 95% CI -0.08 to 0.29; 2 studies, 81 participants). No evidence of a difference was found between LVF and control groups in rate of OTM when using removable orthodontic aligners. Nor did the studies show evidence of a difference between groups for our secondary outcomes, including patient perception of pain, patient-reported need for analgesics at different stages of treatment and harms or side effects.  Photobiomodulation Ten studies assessed the effect of applying low level laser therapy (LLLT) on rate of OTM. We found that participants in the LLLT group had a statistically significantly shorter length of time for the teeth to align in the early stages of treatment (MD -50 days, 95% CI -58 to -42; 2 studies, 62 participants) and required fewer appointments (-2.3, 95% CI -2.5 to -2.0; 2 studies, 125 participants). There was no evidence of a difference between the LLLT and control groups in OTM when assessed as percentage reduction in LII in the first month of alignment (1.63%, 95% CI -2.60 to 5.86; 2 studies, 56 participants) or in the second month (percentage reduction MD 3.75%, 95% CI -1.74 to 9.24; 2 studies, 56 participants). However, LLLT resulted in an increase in OTM during the space closure stage in the maxillary arch (MD 0.18 mm/month, 95% CI 0.05 to 0.33; 1 study; 65 participants; very low level of certainty) and the mandibular arch (right side MD 0.16 mm/month, 95% CI 0.12 to 0.19; 1 study; 65 participants). In addition, LLLT resulted in an increased  rate of OTM during maxillary canine retraction (MD 0.01 mm/month, 95% CI 0 to 0.02; 1 study, 37 participants). These  findings were not clinically significant. The studies showed no evidence of a difference between groups for our secondary outcomes, including OIIRR, periodontal health and patient perception of pain at early stages of treatment. Two studies assessed the influence of applying light-emitting diode (LED) on OTM. Participants in the LED group required a significantly shorter time to align the mandibular arch compared to the control group (MD -24.50 days, 95% CI -42.45 to -6.55, 1 study, 34 participants). There is no evidence that LED application increased the rate of OTM during maxillary canine retraction (MD 0.01 mm/month, 95% CI 0 to 0.02; P = 0.28; 1 study, 39 participants ). In terms of secondary outcomes, one study assessed patient perception of pain and found no evidence of a difference between groups.   AUTHORS' CONCLUSIONS: The evidence from randomised controlled trials concerning the effectiveness of non-surgical interventions to accelerate orthodontic treatment is of low to very low certainty. It suggests that there is no additional benefit of light vibrational forces or photobiomodulation for reducing the duration of orthodontic treatment. Although there may be a limited benefit from photobiomodulation application for accelerating discrete treatment phases, these results have to be interpreted with caution due to their questionable clinical significance. Further well-designed, rigorous RCTs with longer follow-up periods spanning from start to completion of orthodontic treatment are required to determine whether non-surgical interventions may reduce the duration of orthodontic treatment by a clinically significant amount, with minimal adverse effects.

Randomized clinical trial on the effect of intermittent vibrational force application during orthodontic treatment with aligners on RANKL and OPG concentrations in crevicular fluid

Application of intermittent forces by vibration is proposed as an easy-to-use accelerator of dental movement. The purpose of this study was to determine the effect of intermittent vibrational force application during orthodontic aligner treatment on receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) concentrations in crevicular fluid as markers of bone remodeling. This three-arm parallel randomized clinical trial included 45 candidates for malocclusion treatment with aligners, randomly assigned to: Group A (vibrational forces from onset of treatment); Group B (vibrational forces at 6 weeks after treatment onset); or Group C (no vibration). The frequency of aligner adjustment also differed among groups. At different time points, a paper tip was used to draw crevicular fluid samples from a moving lower incisor for RANKL and OPG analysis using ELISA kits. Mixed-model ANOVA found no significant differences in RANKL (A: p = 0.31, B: p = 0.8, C: p = 0.49) or OPG (A: p = 0.24, B: p = 0.58, C: p = 0.59) over time in any group or as a function of the application/non-application of vibration or the frequency of aligner adjustments. Application of this accelerator device did not significantly affect bone remodeling in patients undergoing orthodontic treatment with aligners. However, a nonsignificant improvement in biomarker concentrations was observed when aligners were changed every 7 days and vibration was also applied. Further research is warranted to establish protocols for the application of vibration and the timing of aligner adjustments.

Efficacy and safety of piezocision in accelerating maxillary anterior teeth en-masse retraction: study protocol for a randomized controlled trial

BACKGROUND

Orthodontic treatment is commonly more time-consuming in adults than in teenagers, especially when it comes to the maxillary en-masse retraction, which may take 9 months or even longer. As to solve this concern, orthodontists have been striving to seek new methods for shortening orthodontic treatment time. Piezocision, as a popular alternative treatment, has been widely used in different types of tooth movement. However, its effect on en-masse retraction of maxillary anterior teeth remains unclear. This randomized controlled trial intends to figure out the role piezocision plays in accelerating en-masse retraction.

METHODS

This protocol is designed for a prospective, single-center, assessor-blinded and parallel-group randomized controlled trial. Twenty adult patients aged from 18 to 40 whose orthodontic treatment required bilateral maxillary first premolars extraction will be randomly assigned to the piezocision group and the control group at a ratio of 1:1. The piezocision group will undergo en-masse retraction immediately after the piezo surgery, while the control group will start en-masse retraction directly. Both groups will be followed up every 2 weeks to maintain the retraction force until the end of space closure. The space closing time is set as the primary endpoint. Meanwhile, the secondary endpoints include the change of root length, labial and palatal alveolar bone thickness, vertical bone height, probing depth of maxillary anterior teeth, cephalometric measurements, visual analogue scale, and postoperative satisfaction questionnaire.

DISCUSSION

This study will attempt to provide more convincing evidence to verify whether piezocision will shorten the time of en-masse retraction or not. Distinguished with previous studies, our study has made some innovations in orthodontic procedure and primary outcome measurement, aiming to clarify the efficacy and safety of piezocision-assisted en-masse retraction in Chinese population.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR 1900024297 . Registered on 5 July 2019.

Effect of customized vibratory device on orthodontic tooth movement: A prospective randomized control trial

AIMS:

The primary purpose of the present trial was to evaluate the effect of low-frequency (30Hz) vibrations on the rate of canine retraction.

SETTING AND DESIGN:

Single-center, split mouth prospective randomized controlled clinical trial

METHODS AND MATERIAL:

100 screened subjects (aged18–25 years) were selected; out of which 30 subjects having Class I bimaxillary protrusion or Class II div 1 malocclusion, requiring upper 1^st premolar therapeutic extractions, were selected for the study. A split-mouth study design was prepared for the maxillary arch of each selected individual and was randomly allocated into vibration and nonvibration side (control) groups. A customized vibratory device was fabricated for each subject to deliver low-frequency vibrations (30 Hz). Scanned 3D models were prepared sequentially to assess the amount of tooth movement from baseline (T0),(T1), (T2), (T3), and (T4)-4^th month of canine retraction.

STATISTICAL ANALYSIS USED:

Independent “t” test.

RESULTS:

There was no statistically significant differencein the rate of individual canine retraction among the experimental and control groups when the intergroup comparison was done using independent “t” test at T1-T0, (P = 0.954), T2-T1 (P = 0.244), T3-T2 (P = 0.357), and T4-T3 (P = 0.189).

CONCLUSION:

The low-frequency vibratory stimulation of 30 Hz using a customized vibratory device did not significantly accelerate the rate of orthodontic tooth movement.

TRIAL REGISTRATION:

Registered at ctri.nic.in (CTRI/2019/05/019043).

Orthodontic treatment for crowded teeth in children

BACKGROUND

Crowded teeth develop when there is not enough space in the jaws into which the teeth can erupt. Crowding can affect baby teeth (deciduous dentititon), adult teeth (permanent dentition), or both, and is a common reason for referral to an orthodontist. Crowded teeth can affect a child's self-esteem and quality of life. Early loss of baby teeth as a result of tooth decay or trauma, can lead to crowded permanent teeth. Crowding tends to increase with age, especially in the lower jaw.

OBJECTIVES

To assess the effects of orthodontic intervention for preventing or correcting crowded teeth in children. To test the null hypothesis that there are no differences in outcomes between different orthodontic interventions for preventing or correcting crowded teeth in children.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched four bibliographic databases up to 11 January 2021 and used additional search methods to identify published, unpublished and ongoing studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that evaluated any active interventions to prevent or correct dental crowding in children and adolescents, such as orthodontic braces or extractions, compared to no or delayed treatment, placebo treatment or another active intervention. The studies had to include at least 80% of participants aged 16 years and under.

DATA COLLECTION AND ANALYSIS

Two review authors, independently and in duplicate, extracted information regarding methods, participants, interventions, outcomes, harms and results. We resolved any disagreements by liaising with a third review author. We used the Cochrane risk of bias tool to assess the risk of bias in the studies. We calculated mean differences (MDs) with 95% confidence intervals (CI) for continuous data and odds ratios (ORs) with 95% CIs for dichotomous data. We undertook meta-analysis when studies of similar comparisons reported comparable outcome measures, using the random-effects model. We used the I2 statistic as a measure of statistical heterogeneity.

MAIN RESULTS

Our search identified 24 RCTs that included 1512 participants, 1314 of whom were included in analyses. We assessed 23 studies as being at high risk of bias and one as unclear.  The studies investigated 17 comparisons. Twenty studies evaluated fixed appliances and auxiliaries (lower lingual arch, lower lip bumper, brackets, archwires, lacebacks, headgear and adjunctive vibrational appliances); two studies evaluated removable appliances and auxiliaries (Schwarz appliance, eruption guidance appliance); and two studies evaluated dental extractions (lower deciduous canines or third molars). The evidence should be interpreted cautiously as it is of very low certainty. Most interventions were evaluated by a single study. Fixed appliances and auxiliaries One study found that use of a lip bumper may reduce crowding in the early permanent dentition (MD -4.39 mm, 95% CI -5.07 to -3.71; 34 participants). One study evaluated lower lingual arch but did not measure amount of crowding. One study concluded that coaxial nickel-titanium (NiTi) archwires may cause more tooth movement in the lower arch than single-stranded NiTi archwires (MD 6.77 mm, 95% CI 5.55 to 7.99; 24 participants). Another study, comparing copper NiTi versus NiTi archwires, found NiTi to be more effective for reducing crowding (MD 0.49 mm, 95% CI 0.35 to 0.63, 66 participants). Single studies did not show evidence of one type of archwire being better than another for Titinol versus Nitinol; nickel-titanium versus stainless steel or multistrand stainless steel; and multistranded stainless steel versus stainless steel.  Nor did single studies find evidence of a difference in amount of crowding between self-ligating and conventional brackets, active and passive self-ligating brackets, lacebacks added to fixed appliances versus fixed appliances alone, or cervical pull headgear versus minor interceptive procedures. Meta-analysis of two studies showed no evidence that adding vibrational appliances to fixed appliances reduces crowding at 8 to 10 weeks (MD 0.24 mm, 95% CI -0.81 to 1.30; 119 participants). Removable appliances and auxiliaries One study found use of the Schwarz appliance may be effective at treating dental crowding in the lower arch (MD -2.14 mm, 95% CI -2.79 to -1.49; 28 participants). Another study found an eruption guidance appliance may reduce the number of children with crowded teeth after one year of treatment (OR 0.19, 95% CI 0.05 to 0.68; 46 participants); however, this may have been due to an increase in lower incisor proclination in the treated group. Whether these gains were maintained in the longer term was not assessed. Dental extractions One study found that extracting children's lower deciduous canines had more effect on crowding after one year than no treatment (MD -4.76 mm, 95 CI -6.24 to -3.28; 83 participants), but this was alongside a reduction in arch length. One study found that extracting wisdom teeth did not seem to reduce crowding any more than leaving them in the mouth (MD -0.30 mm, 95% CI -1.30 to 0.70; 77 participants).

AUTHORS' CONCLUSIONS

Most interventions were assessed by single, small studies. We found very low-certainty evidence that lip bumper, used in the mixed dentition, may be effective for preventing crowding in the early permanent dentition, and a Schwarz appliance may reduce crowding in the lower arch. We also found very low-certainty evidence that coaxial NiTi may be better at reducing crowding than single-stranded NiTi, and that NiTi may be better than copper NiTi. As the current evidence is of very low certainty, our findings may change with future research.

The effect of 12 weeks of mechanical vibration on root resorption: a micro-CT study

OBJECTIVE

The aim was to investigate the effect of mechanical vibration on root resorption with or without orthodontic force application.

MATERIAL AND METHODS

Twenty patients who required maxillary premolar extractions as part of orthodontic treatment were randomly divided into two groups of 10: no-force group and force group. Using a split-mouth procedure, each patient's maxillary first premolar teeth were randomly assigned as either vibration or control side for both groups. A buccally directed vibration of 50 Hz, with an Oral-B HummingBird device, was applied to the maxillary first premolar for 10 min/day for 12 weeks. After the force application period, the maxillary first premolars were extracted and scanned with micro-computed tomography. Fiji (ImageJ), performing slice-by-slice quantitative volumetric measurements, was used for resorption crater calculation. Total crater volumes were compared with the Wilcoxon and Mann-Whitney U tests.

RESULTS

The total crater volumes in the force and no-force groups were 0.476 mm3 and 0.017 mm3 on the vibration side and 0.462 mm3 and 0.031 mm3 on the control side, respectively. There was no statistical difference between the vibration and control sides (P > 0.05). There was more resorption by volume in the force group when compared to the no-force group (P < 0.05).

CONCLUSION

Mechanical vibration did not have a beneficial effect on reducing root resorption; however, force application caused significant root resorption.

Peak loads on teeth from a generic mouthpiece of a vibration device for accelerating tooth movement

INTRODUCTION

The effect of vibrational force (VF) on accelerating orthodontic tooth movement depends on the ability to control the level of stimulation in terms of its peak load (PL) on the tooth. The objective of this study was to investigate the PL distribution on the teeth when a commercial VF device is used.

METHODS

Finite element models of a human dentition from cone-beam computed tomography images of an anonymous subject and a commonly used commercial VF device were created. The device consists of a mouthpiece and a VF source. The maxilla and mandible bites on the mouthpiece with the VF applied to it. Interface elements were used between the teeth and the mouthpiece, allowing relative motion at the interfaces. The finite element model was validated experimentally. Static load and VF with 2 frequencies were used, and the PL distributions were calculated. The effects of mouthpiece materials and orthodontic appliances on the PL distribution were also investigated.

RESULTS

The PL distribution of this kind of analyzed device is uneven under either static force or VF. Between the anterior and posterior segments, the anterior segment receives the most stimulations. The mouthpiece material affects the PL distribution. The appliance makes the PL more concentrated on the incisors. The VF frequencies tested have a negligible influence on both PL magnitude and distribution.

CONCLUSIONS

The device analyzed delivers different levels of stimulation to the teeth in both maxilla and mandible. Changing the material property of the mouthpiece alters the PL distribution.

Impact of photobiomodulation and low-intensity pulsed ultrasound adjunctive interventions on orthodontic treatment duration during clear aligner therapy: A retrospective study

OBJECTIVE

To assess the efficiency of low-intensity pulsed ultrasound (LIPUS) and photobiomodulation (PBM) interventions in accelerating orthodontic tooth movement during clear aligner therapy (CAT).

MATERIALS AND METHODS

This retrospective study was carried out on the records of 84 subjects who were treated using CAT. Twenty-eight patients were treated using CAT with a daily use of LIPUS for 20 minutes, 28 patients were treated using CAT with a daily use of PBM for 10 minutes, and 28 patients were treated using CAT alone. The total duration of treatment was recorded for all patients. One-way analysis of variance and post hoc Tukey test were used to assess whether there was any significant difference in total treatment duration among the three groups (P < .05).

RESULTS

The mean treatment durations in days were 719 ± 220, 533 ± 242, and 528 ± 323 for the control, LIPUS, and PBM groups, respectively. The LIPUS group showed a 26% reduction, on average, in treatment duration when compared with the control group, whereas the PBM group showed an average 26.6% reduction in the treatment duration when compared with the control group. The results showed that there were statistically significant differences among the groups (P = .011). Treatment durations were significantly reduced in the LIPUS and PBM groups as compared with the control (P = .027 and P = .023, respectively), with no statistically significant differences between the LIPUS and PBM groups (P = .998).

CONCLUSIONS

Daily use of LIPUS or PBM as adjunctive interventions during CAT could reduce the duration of orthodontic treatment.

Does observational study on the effectiveness of the Twin Blocks overestimate or underestimate the results? A comparative analysis of retrospective samples versus randomized controlled trial

BACKGROUND AND OBJECTIVES

Class II malocclusion is one of the most common orthodontic problems. The Twin Block appliance has proven to be the most popular appliance for the correction of these malocclusions. Although randomized controlled trials (RCTs) on the Twin Block appliance have reported the changes to be mainly dentoalveolar, several nonrandomized studies have reported a significant skeletal improvement in these patients. Hence, the aim of this study was to compare the effectiveness of Twin Block appliance evaluated using an RCT or retrospectively selected cases (RSC) for the treatment of Class II Division 1 malocclusion in an adolescent population.

METHODS

This was a retrospective study. The results for an RCT were selected from a UK Class II multicenter study. Sixty-three patients from the trial were included. This group was matched with retrospectively selected Class II cases treated with a Twin Block functional appliance and their results submitted for Membership in Orthodontics examination in the United Kingdom, from four centers. The primary outcome was skeletal measurement ANB (A point, nasion, B point). Secondary outcomes included final peer assessment rating (PAR) scores and final overjet. Intrarater reliability of measurements was assessed. Independent samples t-test was carried out to look at the difference between the groups.

RESULTS

The reliability assessment showed excellent agreement for all measurements. The data were normally distributed. There was a statistically significant difference favoring the RSC group for final overjet (mean difference [MD] = 1.068, 95% confidence interval [CI] -0.67 to 1.47, P = 0.000) and final PAR (MD = 4.0, 95% CI -0.79 to 5.5, P = 0.000). There was no significant difference in the scores for final ANB (MD = 0.34, 95% CI -0.39 to 1.07, P = 0.33).

CONCLUSION

The RSCs show significantly improved overjet and PAR scores at the end of treatment and no statistically significant difference for skeletal change. The study raises the question of a potential role of observational studies in evaluating the effect of an intervention in orthodontics.

Performance comparison of vibration devices on orthodontic tooth movement - A systematic review and meta-analysis

Background

To evaluate the efficiency of vibratory devices in altering rate of orthodontic tooth movement.

Methods

A literature search up to January 31, 2020 was conducted in three electronic databases: PubMed, Cochrane Central Register of Controlled Trials (CENTRAL) and Science Direct, to identify studies on vibratory devices reporting any alteration in tooth movement as a primary outcome. Only articles published in English language were included. A meta-analysis was done to compare the amount of tooth movement (in mm) in patients treated with vibratory devices compared to control groups, to quantify weighted treatment effects.

Results

A total of two split mouth studies, six parallel arm randomized control trials (RCT) one split mouth RCT, and three regular RCTs were assessed qualitatively. Quantitative assessment was done for 8 randomized trials using a forest plot (310 patients). Pooled data showed increase in the amount of tooth movement by 0.34 ​mm (95% CI:0.25,0.42). There was a statistically significant difference noted for this result at p ​< ​0.00001.

Conclusion

Current evidence suggests a moderate to high level of certainty in regard to included studies in this systematic review and meta-analysis. Vibratory devices when used in conjunction with fixed orthodontic appliances show significant increase in the rate of tooth movement. These devices can be used by clinicians to reduce treatment duration and patient discomfort.

PROSPERO registration

CRD42020169675.

Comparative assessment of the rate of orthodontic tooth movement in adolescent patients undergoing treatment by first bicuspid extraction and en mass retraction, associated with low-frequency mechanical vibrations in passive self-ligating and conventional brackets: A randomized controlled trial

BACKGROUND

Low-frequency vibrations are one of the many non-surgical modalities aimed at increasing the rate of orthodontic tooth movement.

OBJECTIVE

The present trial was conducted to assess the efficacy of low-frequency vibrations in increasing the rate of orthodontic tooth movement in adolescent patients undergoing fixed mechanotherapy with passive self-ligating brackets and conventional brackets.

MATERIALS AND METHODS

Setting and sample population: department of orthodontics and dentofacial orthopaedics in a nationally accredited dental college. Participants, study design and methods: 65 patients were randomly allocated to three groups. Two experimental groups consisted of passive self-ligating and conventionally ligated appliances received low-frequency vibrations. The control group did not receive any vibrations. Allocation ratio was 1:1:1.32. Eligibility criteria: adolescent patients with sound and healthy dentition, incisor irregularity<5mm.

PRIMARY OUTCOME

rate of orthodontic tooth movement in mm/month. Randomization and blinding: computer-generated random allocation sequencing was done and data assessor was blinded.

STATISTICS

the Q-Q plot and Shapiro-Wilks test judged the normality of the data. The parametric test included ANCOVA and post-hoc analysis.

RESULTS

No statistically significant enhancement of tooth movement was seen in the experimental groups, when comparison was done with the control group P>0.05. Comparison between the two experimental groups did not reveal any significant difference either.

CONCLUSION

No statistically significant increase of orthodontic tooth movement was seen with low-frequency vibrations and the mode of ligation did not have any effect in increasing the rate of tooth movement either.

Effectiveness of vibrational forces on orthodontic treatment : A randomized, controlled clinical trial

AIM

AcceleDent® Aura (OrthoAccel® Technologies, Bellaire, TX, USA) is a class II medical device with U.S. Food and Drug Administration approval that uses SoftPulse Technology™ to increase the speed of tooth movement. The aim of this study was to evaluate the application of vibrational forces on the rate of canine distalization.

METHODS

A total of 20 patients (10 boys and 10 girls) who had class II division 1 malocclusion or severe crowding and indicated first premolar extractions for treatment were included in the study. The patients were divided into two groups: 8 in the control group and 12 in the study group. Three-dimensional digital models were taken just before canine distalization and after space closure using the 3Shape TRIOS® R700 (3Shape Inc., Copenhagen, Denmark) device. Linear measurements between molars and canines were evaluated. The results were assessed with SPSS 23.0 program (IBM, Armonk, NY, USA).

RESULTS

One subject was excluded from the study group due to insufficient oral hygiene and poor patient compliance. Tooth movement rates were 1.06 mm/month for mandibular and maxillary canine teeth in the control group. In the study group, tooth movement rates were 1.24 mm/month for maxillary canines and 1.09 mm/month for mandibular canines. These differences were not statistically significant (p > 0.05).

CONCLUSION

AcceleDent® Aura is an easy-to-use device; however, in our study its application did not have any positive effects on canine retraction rates.

Biomarkers of orthodontic tooth movement with fixed appliances and vibration appliance therapy: a pilot study

INTRODUCTION

The aim of this study was to investigate the effect of supplemental vibratory force on biomarkers of bone remodelling during orthodontic tooth movement, the rate of mandibular anterior alignment (RMAA), and compliance with a vibration device.

DESIGN, SETTINGS, AND PARTICIPANTS

Forty patients between the ages 15-35 undergoing fixed appliance treatment that presented to a university orthodontic clinic were randomly allocated to supplemental use of an intraoral vibrational device (n = 20, AcceleDent®) or fixed appliance only (n = 20). Salivary multiplex assay was completed to analyse the concentration of selected biomarkers of bone remodelling before treatment (T0) and at three following time points (T1, T2, T3), 4-6 weeks apart. Irregularity of the mandibular anterior teeth and compliance was assessed at the same trial time points. Data were analysed blindly on an intention-to-treat basis with descriptive statistics, Mann-Whitney U-test, Wilcoxon signed-rank test, and linear mixed effects regression modelling.

RESULTS

No difference in the changes in salivary biomarkers of bone remodelling and RMAA between groups at any time point over the trial duration was observed. No correlation was found between changes in irregularity and biomarker level from baseline to another time point. Lastly, there was no association between RMAA and compliance with the AcceleDent® device.

CONCLUSIONS

Supplemental vibratory force during orthodontic treatment with fixed appliances does not affect biomarkers of bone remodelling or the RMAA.

LIMITATIONS

The main limitation of the study was the small sample size and the large variability in the salivary biomarkers.

HARMS

No harms were observed during the duration of the trial.

PROTOCOL

The protocol was not published prior to trial commencement.

REGISTRATION

The study was registered in Clinical Trials.gov (NCT02119455) first posted on April 2014.

The effectiveness of supplemental vibrational force on enhancing orthodontic treatment. A systematic review

BACKGROUND AND OBJECTIVES

The results from the literature regarding the influence of supplemental vibrational forces (SVFs) on orthodontic treatment are controversial. Therefore, this systematic review aimed to evaluate whether SVFs have positive effects, such as in accelerating tooth movement, alleviating pain, and preventing root resorption, in orthodontic patients.

SEARCH METHODS

Searches through five electronic databases (PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Central) were complemented by hand searches up to January, 2019.

SELECTION CRITERIA

Randomized controlled trials and controlled clinical trials reporting on the effects of SVFs in orthodontic patients in English were included.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction, and a risk of bias assessment were independently performed by two reviewers. Study characteristics and outcomes were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A qualitative analysis of the effects of SVFs on orthodontic tooth movement, pain experience, and root resorption was conducted.

RESULTS

Thirteen studies, including nine clinical trials, were eligible for inclusion in the systematic review. There was no significant evidence to support the positive effects of SVFs in orthodontic patients, neither in accelerating tooth movement nor in alleviating pain experience. According to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria, the quality of the evidence was very low for all the outcomes in the qualitative analysis.

LIMITATIONS

The results of this systematic review are based on a limited number of studies and the methodological heterogeneity and non-comparability of original outcomes made it difficult to conduct a meta-analysis.

CONCLUSIONS

There is insufficient evidence to support the claim that SVFs have positive clinical advantages in the alignment of the anterior teeth. The potential positive effects of vibrational forces on space closure, pain experience, and root resorption in orthodontic patients are inconclusive with no sufficient information at present. High-quality clinical trials with larger sample sizes are needed to find more comprehensive evidence of the potential positive effects of vibrational forces.

REGISTRATION

The protocol for this systematic review was registered on PROSPERO (CRD42018098788).

FUNDING

This study has not received any contributions from private or public funding agencies.

CONFLICT OF INTEREST

None.

Accelerated orthodontics: Getting ahead of ourselves?

There is disagreement as to what constitutes an acceptable duration for orthodontic treatment but seeming unanimity that acceleration is required. This contention has spawned a range of surgical and non-surgical adjuncts designed to accelerate orthodontic tooth movement, geared at reducing overall treatment times while maintaining optimal occlusal results. Largely, however, marketed non-surgical adjuncts and involved surgical procedures have shown equivocal effectiveness in reducing treatment times. Notwithstanding this, a range of key treatment decisions and approaches may have a more potent effect. While external solutions may offer alluring possibilities, perhaps, more mundane realities including refinement of orthodontic planning and decision-making with efficiency and process, as well as final outcome, in mind continue to offer the most accessible and influential means of improving orthodontic efficiency?

The Effectiveness of Micro-osteoperforations during Canine Retraction: A Three-dimensional Randomized Clinical Trial

Aim:

A major challenge in orthodontics is decreasing treatment time without compromising treatment outcome. The purpose of this split-mouth trial was to evaluate micro-osteoperforations (MOPs) in accelerating orthodontic tooth movement.

Materials and Methods:

Eight patients of both genders were selected, age ranging between 15 and 40 years, with Class II Division 1 malocclusion. The participants in this trial with MOPs were randomly allocated to either the right or the left side, distal to the maxillary canine. First maxillary premolars were extracted as part of the treatment plan on both sides and then canine retraction was applied. Miniscrews were used to support anchorage. MOP side received (three small perforations) placed on the buccal bone, distal to the maxillary canine, on randomly selected side using an automated mini-implant driver and the other side was the control side. Blinding was used at the data collection and analysis stages. The primary outcome was the rate of canine retraction measured with a three-dimensional (3D) digital model from the baseline to the first 2 weeks superimposed at the rugae area from the baseline to the first, second, and third months. The following secondary outcomes were examined: anchorage loss, canine tipping, canine rotation, root resorption, plaque index, and gingival index. Pain level, pain interference with the patients’ daily life, patients’ satisfaction with the procedure and degree of ease, willingness to repeat the procedure, and recommendation to others were also evaluated.

Results:

No statistically significant difference was observed in the rates of tooth movement between the MOP and the control sides at all-time points (first month: P = 0.77; mean difference, 0.2 mm; 95% CI, −0.13, 0.18 mm; second month: P = 0.50; mean difference, −0.08 mm; 95% CI, −0.33, 0.16 mm; third month: P = 0.76; mean difference, −0.05 mm; 95% CI, −0.40, 0.29 mm). There were also no differences in anchorage loss, rotation, tipping, root resorption, plaque index, periodontal index, and pain perception between the MOP and control sides at any time point (P > 0.05). MOPs had no effect on the patients’ daily life except for a feeling of swelling on the first day (P = 0.05). Level of satisfaction and degree of easiness of the procedure were high.

Conclusion:

According to our clinical trial, MOPs cannot help in speeding up a canine retraction.

Effects of mechanical vibrations on maxillary canine retraction and perceived pain: a pilot, single-center, randomized-controlled clinical trial

The aim of this study was to investigate the effect of mechanical vibratory stimulation on maxillary canine retraction and pain perception in adolescents undergoing full-fixed orthodontic treatment with extraction. A pilot randomized-controlled clinical trial was conducted in one university orthodontic clinic. Twenty-one healthy adolescents who underwent full-fixed orthodontic treatment with maxillary first-premolar extraction were recruited. Subjects were randomly assigned to the experimental group (N = 10) that used a mechanical vibration device (AcceleDent Aura, OrthoAccel Technologies, Inc.) or the control group (N = 11) that did not receive a vibration device. The evaluation timepoints were T₀ = day of initial canine retraction; T₁ = 4 weeks post-initiation; T₂ = 8 weeks post-initiation; and T₃ = 12 weeks post-initiation. Three-dimensional palatal landmark superimpositions were made to assess amount of tooth movement (mm) at each visit, monthly rate of tooth movement (mm), and perceived pain levels (VAS scores). The total amount of tooth movement was observed in the control versus experimental groups, respectively, as 1.12 ± 0.22 mm versus 1.39 ± 0.36 mm at 4 weeks (p = 0.058), 2.59 ± 0.37 mm versus 2.49 ± 0.76 mm at 8 weeks (p = 0.702), and 3.54 ± 0.23 mm versus 3.37 ± 1.37 mm at 12 weeks (p = 0.716). The rate of tooth movement was 1.21 ± 0.32 mm/month in the control and 1.12 ± 0.20 mm/month in the experimental groups, which was not statistically significant at any of the timepoints and neither was the level of pain. This study found no statistically significant differences in canine retraction and pain perception between the experimental and control groups. We propose that further optimization of accelerated tooth movement with mechanical vibration devices is necessary.

[Adjunctive interventions to accelerate orthodontic tooth movement]

Orthodontic treatment is a time-consuming process whose duration usually takes 2-3 years. In general, long-term treatment duration possesses higher risks of complications, which may have adverse impact on patients. Therefore, exploring safe and effective adjunctive interventions to accelerate orthodontic tooth movement and shortening the treatment duration are of profound clinical significance. Currently, numerous adjunctive interventions have been generated and developed to accelerate orthodontic tooth movement, which can be divided into two main categories: surgical and non-surgical. However, an intervention that is widely accepted as a routine practice in orthodontic clinic is lacking. This article aims to review com-mon adjunctive interventions used to accelerate orthodontic tooth movement. This review can be used as a basis to guide clinical practice, shorten treatment duration, and improve patients' prognosis.

Effectiveness and importance of powered tooth brushes in tooth movement

Introduction:

Effectiveness of vibratory stimulus from a commonly available battery-powered tooth brush in accelerating orthodontic tooth movement was tested by a randomized controlled split-mouth study.

Materials and Methods:

Twenty-three subjects with bimaxillary protrusion, requiring extraction of all first premolars and requiring maximum anchorage, were chosen. After initial leveling and aligning, miniscrews were placed between the first molar and the second premolar in the maxillary right and left quadrants and loaded with 150-g nickel–titanium closed-coil springs for individual canine retraction. Additional 5 min of vibratory stimulus thrice daily was applied on the experimental side. The mean treatment duration was 3 months.

Results:

There was no significant difference of means of the canine distal movement between the experimental and the control sides (P = 0.70).

Conclusion:

Application of vibratory stimulus with powered tooth brush during canine retraction was not seen to have an acceleratory effect on orthodontic tooth movement.

Orthodontic treatment time: can it be shortened?

INTRODUCTION

In the literature, no consensus has been reached about orthodontic treatment time. Similarly, the determining factors of the latter have not yet been completely elucidated.

OBJECTIVE

The aim of the present article was to deepen the discussion on the major factors influencing orthodontic treatment time, as well as to present some strategies that have proven effective in controlling and shortening it.

METHOD

Based on evidences found in the literature, the method focussed in providing the basis for clinical decision-making.

CONCLUSIONS

Treatment time varies according to the type of malocclusion and treatment options. Orthodontist's influence, patient's characteristics and compliance are all decisive in determining treatment time, while the effects provided by orthodontic appliances and methods used to speed tooth movement up seem little effective.

Effectiveness of using a Vibrating Device in Accelerating Orthodontic Tooth Movement: A Systematic Review and Meta-Analysis

Objective

The aim of current systematic review was to evaluate the efficiency of the vibrating devices in accelerating orthodontic tooth movement.

Methods

A systemic unrestricted search was done in three electronic databases up to July 2018. A manual search was also performed. Eligibility criteria included Randomized clinical trials (RCTs), quasi randomized clinical trials and prospective controlled trials (CCTs) comparing the rate of the tooth movement with and without vibrating devices. The study characteristics and data extraction of the vibrating device group and control group were performed by two reviewers independently.

Results

Seven articles were eligible to be included in the qualitative analysis. Three of them were included in meta analysis. One hundred and five patients received vibrating device to accelerate orthodontic treatment while forty-nine patients received shame device and seventy-eight patients were control group.

Conclusion

There was no significant difference between vibrating devices group and control group. There is no evidence that vibrating appliances are effective in acceleration of orthodontic tooth movement.

Effects of two frequencies of vibration on the maxillary canine distalization rate and RANKL and OPG secretion: A randomized controlled trial

OBJECTIVES

To investigate the effects of 30 and 60 Hz vibratory stimulus on canine distalization and RANKL and OPG secretion.

SETTING AND SAMPLE POPULATION

Sixty patients requiring canine distalization at the Orthodontic Clinic, Prince of Songkla University.

MATERIALS AND METHODS

Patients were randomly assigned to 30 Hz vibration (n = 20), 60 Hz vibration (n = 20), or the control group (n = 20). Modified electric toothbrushes were used to apply vibration to the randomly selected canine for 20 min/day by the investigator combined with 60 cN continuous distalization force from day 1 to day 7. RANKL and OPG were analysed before (T1) and 24 hours (T2), 48 hours (T3) and 7 days (T4) after initiation of distalization. From day 8, vibratory devices were used by the subjects at home. Rate of canine distalization (T1 to 3 months after initiation [T5]) was calculated. Kruskal-Wallis tests were used for multiple comparisons (significance level, 0.05).

RESULTS

Canine distalization rate was not different between groups (median; 0.82, 0.87, and 0.83 mm/month for 30, 60 Hz, and control group, respectively; P > 0.05). No within- or between-group differences in RANKL and OPG were observed (P > 0.05), except RANKL on the compression side of the control group was significantly higher at T2, T3 and T4 than T1 (P < 0.001).

CONCLUSION

In the clinic, 30 and 60 Hz vibratory stimulus have no additive effect on rate of canine distalization rate, RANKL and OPG secretion or RANKL/OPG ratio.

[Bone mechanobiology, an emerging field: a review]

INTRODUCTION

Mechanobiology, at the interface between biology and biophysics, studies the impact of mechanical forces on tissues, cells and biomolecules. The application of orthodontic forces, followed by induced tooth displacement, is a striking example of its clinical application.

OBJECTIVE

The purpose of this article was to compile a review of the literature on the subject of mechanobiology; from its detection at bone level to the presentation of stimulated intracellular pathways.

MATERIALS AND METHODS

The literature search was conducted on the Pubmed database in April 2018, with associations of the terms "mechanobiology", "orthodontics", "cell culture", "physiopathology".

RESULTS

Three major areas of research were selected: highlighting of the phenomenon and its application in the field of bone biology; the cellular effectors of mechanobiology and its clinical applications. The use of mechanobiology in dentofacial orthopedics opens up a new field of reflection for clinicians regarding future advances in orthodontics.