Supplemental vibrational force does not reduce pain experience during initial alignment with fixed orthodontic appliances: a multicenter randomized clinical trial

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).

Effects of Vibration on Accelerating Orthodontic Tooth Movement in Clinical and In Vivo Studies: A Systematic Review

This systematic review aims to assess the impact of high (>30 Hz) and low (≤30 Hz) frequency vibrations on orthodontic tooth movement (OTM). Several articles were collected through a systematic search in the databases MEDLINE and SCOPUS, following PRISMA methodology and using a PICO question. Relevant information on selected articles was extracted, and the quality of each study was assessed by the quality assessment tools EPHPP, ROBINS-1 and STAIR. Out of 350 articles, 30 were chosen. Low-frequency vibrations did not seem to accelerate OTM with aligners or fixed appliances, despite some positive outcomes in certain studies. Conversely, high-frequency vibrations were linked to increased aligner change, tooth movement, and space closure with fixed appliances. In vivo studies reported favourable results with high-frequency vibrations (60 Hz to 120 Hz), which stimulate bone biomarkers, facilitating alveolar bone remodelling. The results suggest that high-frequency vibration effectively speeds up orthodontic tooth movement, showing promise in both in vivo and clinical studies. Larger-scale research is needed to strengthen its potential in orthodontics.

Proposal regarding potential causes related to certain complications with dental implants and adjacent natural teeth: Physics applied to prosthodontics

PURPOSE

Complications can and do occur with implants and their restorations with causes having been proposed for some single implant complications but not for others.

METHODS

A review of pertinent literature was conducted. A PubMed search of vibration, movement, and dentistry had 175 citations, while stress waves, movement, and dentistry had zero citations as did stress waves, movement. This paper discusses the physics of vibration, elastic and inelastic collision, and stress waves as potentially causative factors related to clinical complications.

RESULTS

Multiple potential causes for interproximal contact loss have been presented, but it has not been fully understood. Likewise, theories have been suggested regarding the intrusion of natural teeth when they are connected to an implant as part of a fixed partial denture as well as intrusion when a tooth is located between adjacent implants, but the process of intrusion, and resultant extrusion, is not fully understood. A third complication with single implants and their crowns is abutment screw loosening with several of the clinical characteristics having been discussed but without determining the underlying process(es).

CONCLUSIONS

Interproximal contact loss, natural tooth intrusion, and abutment screw loosening are common complications that occur with implant retained restorations. Occlusion is a significant confounding variable. The hypothesis is that vibration, or possibly stress waves, generated from occlusal impact forces on implant crowns and transmitted to adjacent teeth, are the causative factors in these events. Since occlusion appears to play a role in these complications, it is recommended that occlusal contacts provide centralized stability on implant crowns and not be located on any inclined surfaces that transmit lateral forces that could be transmitted to an adjacent tooth and cause interproximal contact loss or intrusion. The intensity, form, and location of proximal contacts between a natural tooth located between adjacent single implant crowns seem to play a role in the intrusion of the natural tooth. Currently, there is a lack of information about the underlying mechanisms related to these occurrences and research is needed to define any confounding variables.

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.

Pain profile during orthodontic levelling and alignment with fixed appliances reported in randomized trials: a systematic review with meta-analyses

OBJECTIVE

To assess the pain profile of patients in the levelling/alignment phase of orthodontic treatment, as reported from randomized clinical trials.

MATERIALS AND METHODS

Five databases were searched in September 2022 for randomized clinical trials assessing pain during levelling/alignment with a visual analogue scale (VAS). After duplicate study selection, data extraction, and risk-of-bias assessment, random effects meta-analyses of mean differences (MDs) and their 95% confidence intervals (CIs) were performed, followed by subgroup/meta-regression, and certainty analyses.

RESULTS

A total of 37 randomized trials including 2277 patients (40.3% male; mean age 17.5 years) were identified. Data indicated quick pain initiation after insertion of orthodontic appliances (n = 6; average = 12.4 mm VAS), a quick increase to a peak at day 1 (n = 29; average = 42.4 mm), and gradually daily decrease the first week until its end (n = 23; average = 9.0 mm). Every second patient reported analgesic use at least once this week (n = 8; 54.5%), with peak analgesic use at 6 h post-insertion (n = 2; 62.3%). Patients reported reduced pain in the evening compared to morning (n = 3; MD =  - 3.0 mm; 95%CI =  - 5.3, - 0.6; P = 0.01) and increased pain during chewing (n = 2; MD = 19.2 mm; 95% CI = 7.9, 30.4; P < 0.001) or occlusion of the back teeth (n = 2; MD = 12.4 mm; 95% CI = 1.4, 23.4; P = 0.3), while non-consistent effects were seen for patient age, sex, irregularity, or analgesic use. Subgroup analyses indicated increased pain among extraction cases and during treatment of the lower (rather than the upper) arch, while certainty around estimates was moderate to high.

CONCLUSIONS

Evidence indicated a specific pain profile during orthodontic levelling/alignment, without signs of consistent patient-related influencing factors.

Mechanical vibration as an adjunct to clear aligner treatment for accelerating tooth movement: A review

Many patients, particularly adults, may prefer clear aligner treatment due to its esthetics and ease of use. Some studies have shown that mechanical vibration can affect the rate of tooth movement and other aspects of orthodontic treatment. The purpose of this systematic review was to substantiate the effects of vibration as an adjunct to clear aligner treatment. A comprehensive search of the PubMed, Embase, Cochrane library, and Scopus and also hand searching of reference lists was conducted for finding published studies up to March 2021. Two authors reviewed the titles and abstracts independently to select relevant studies and the full texts where there was some skepticism. Seven papers were included in this study following removing duplicates and irrelevant studies, four of which were randomized controlled trial and three were retrospective studies. In the majority of studies, High-Frequency Vibration (HFV) has shown to be effective in accelerating tooth movement and reducing the exchange interval of aligners. Little data have advocated that HFV can increase bone density, reduce pain or root resorption. It seems that HFV is more effective than low frequency vibration in patients treated with clear aligners. Based on a low level of certainty, HFV can increase the rate of tooth movement and decrease the exchange interval of clear aligners. Further investigation is necessary to clarify the effects of vibration on pain and discomfort, bone density, and root resorption.

The Effects of Low-frequency Vibration on Aligner Treatment Duration: A Clinical Trial

OBJECTIVES

The aim of this study was to investigate the effectiveness of an orthodontic tooth movement acceleration device (AcceleDent, OrthoAccel Technologies, Houston, Texas) when used during an aligner treatment.

MATERIALS AND METHODS

Adult patients who began an aligner treatment (Lineo, Micerium Lab, Avegno, Italy) were allocated to two treatment groups. The first one (Group A), with a 7-day aligner change regimen, used the AcceleDent device for 20 min per day, whereas the second one (Group B) changed the aligners every 14 days and did not use any device. The registered outcomes were the possibility of completing the treatment, the number of aligners needed and treatment duration in the two groups. Moreover, we assessed patients' perception of pain during the first week of treatment.

RESULTS

Twenty-four patients were allocated to Group A or B depending on the acceptance of AcceleDent use. Patients which used AcceleDent (Group A) completed the treatment using each aligner for fewer days than those belonging to Group B (9.0 ± 1.0 and 15.4 ± 1.2 days, respectively) (P < 0.001). As a secondary outcome, a significant difference was found in pain perception during the first week of treatment between the two groups (P < 0.05).

CONCLUSIONS

This controlled clinical trial shows that is possible to apply a 7-day change regimen together with AcceleDent use and successfully complete an aligner treatment with a significant saving of time when compared to a standard 14-days change regimen. Finally, the use of this device allowed reduction in pain perception during the orthodontic treatment.

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.

Interval Vibration Reduces Orthodontic Pain Via a Mechanism Involving Down-regulation of TRPV1 and CGRP

BACKGROUND/AIM

The transient receptor potential vanilloid 1 (TRPV1) ion receptor is involved in the release of calcitonin gene-related peptide (CGRP), a major contributor to orthodontic pain. Approaches that attenuate expression of TRPV1 and CGRP may reduce orthodontic pain. We explored the ability of high-frequency interval vibration to reduce orthodontic pain.

MATERIALS AND METHODS

Orthodontic force (50 g) was applied to both maxillary first molars in 8-week-old Wistar rats (n=72). Vibration was applied at 125 Hz for 15 min/day. Duration of face grooming was assessed as a measure of orthodontic pain. Immunofluorescence and western blotting were used to assess TRPV1 and CGRP in the trigeminal ganglia.

RESULTS

Compared to orthodontic force alone, application of vibration significantly decreased the duration of face grooming at 24 h and day 3 and reduced expression of TRPV1 and CGRP at 24 h.

CONCLUSION

Vibration represents a promising mechanical approach to reduce orthodontic pain.

Perception of Iraqi Orthodontists and Patients toward Accelerated Orthodontics

Background/Purpose. In the literature, no consensus about the duration of orthodontic treatment has been reached out. This study aimed to identify orthodontist's and patient's perception about the time of orthodontic treatment and their willingness to undergo and pay for various acceleration techniques and procedures. Materials and Methods. An electronic survey was conducted from August to October 2020. The questionnaire consisted of 20 multiple choice questions which was designed and emailed to members of the Iraqi Orthodontic Society and self-administered to patients in several orthodontic centers in Baghdad. The questionnaire included questions about the perception toward the duration of orthodontic treatment, approval of different procedures used to reduce treatment time, and how much fee increment they are able to pay for various techniques and appliances. Descriptive and chi-square test statistics were used, and the level of significance was set at p ≤ 0.05. Results. The response rate was 78.7%. The willingness for additional techniques and procedures was rated in the following order: customized appliances: 50.8% orthodontists and 38.4% patients, followed by intraoral vibrating devices: 49.2% orthodontists and 38.1% patients, piezocision: 10.2% orthodontists and 8.2% patients, and corticotomies: 8.1% orthodontists and 5.9% patients. Most orthodontists were willing to pay up to 40% of treatment income for the acceleration procedure, while the payment of patients was up to 20%. Conclusion. Both orthodontists and patients were interested in techniques that can decrease the treatment duration. Noninvasive accelerating procedures were more preferable by orthodontists and patients than invasive surgical procedures.

Young Adults' Preferences and Willingness to Pay for Invasive and Non-invasive Accelerated Orthodontic Treatment: A Comparative Study

To evaluate the preference of young adult patients and their willingness to pay for the different approaches accessible to accelerate orthodontic tooth movement. A cross-sectional survey was conducted in Jeddah, Saudi Arabia from September to December 2019. Young adult orthodontic patients from 18 to 45 years old were interviewed via online survey regarding their perception to the extent of treatment, acceptability of non-invasive (customized appliances and medications) and invasive (surgery) approaches accessible to accelerate orthodontic treatment and increase in fees they were willing to pay. Statistical analyses were performed, and gender difference was calculated at P < .05. There are 100 respondents: 70% aged between 18 to 25, 50% male, and 56% with annual income <10 000 SR. About 72% of the respondents decided that treatment takes longer period and 51% wished it would last for less than 6 months. Customized appliances were reported to be the most convenient to use (58%) and to pay (44%), followed by medications (48%). On the other hand, surgery was reported to be the most inconvenient to use (58%) and to pay for (55%). About 70% of the respondents were unwilling to pay more than 10% to 20% for all procedures assessed; considerable variation was not observed in responses between gender at 95% confidence level. Majority of the respondents believed that orthodontic treatment is taking lengthy duration. Less invasive, nonsurgical techniques and procedures were more preferred. Likewise, financial factors play vital role in the selection of their preferred approach. Most of them agrees to provide up to 20% increment of the fee for additional procedures.

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.

[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.

Patients' Perceptions To Reduced Orthodontic Treatment Time In Saudi Arabia

PURPOSE

To evaluate patients' perceptions regarding orthodontic treatment duration, cost, and willingness to undergo different procedures and techniques available to accelerate orthodontic tooth movement in Saudi Arabia.

PATIENTS AND METHODS

A cross-sectional survey was conducted in Saudi Arabia from January to March 2019. Patients from multiple centers were electronically surveyed regarding their perception of orthodontic treatment duration, acceptance of appliances and techniques available to shorten the duration of orthodontic treatment, and how much increase in fees they were willing to pay for those appliances and techniques. Descriptive and group comparison statistics were conducted, and the significance level was set at p<0.05.

RESULTS

The response rate was 200/400 (50%): 50.5% were (>18-25 years old), 67.5% female, 80% Saudi, 67.5% self-pay and 52% with annual income <10,000 SR. A total of 83% of the participants agree that orthodontic treatment takes too long, and 55.5% wish it takes less than 6 months. The preferences for additional procedures were ranked in the following order: customized wires ranked 1 by 52.5%, followed by FDA (Food & Drug Administration) approved teeth vibrators by 40.5%, FDA approved drug injections by 33.5%, piezocision by 32.5%, and corticotomies by 46% of the participants. No significant differences in ranking between the groups according to age and annual income (p>0.05). 47.5% of the participants were able to pay for additional procedures. An increase in treatment fees was reported for up to (30-40%) for FDA approved teeth vibrators by 59% of the participants, followed by FDA approved drug injections by 33% of the participants. A significant difference in responses between the groups was reported according to gender and annual income (p<0.05).

CONCLUSION

Most of the patients strongly agreed that orthodontics treatment takes too long. The highest percentages of patients perceived customized wires as the most acceptable technique to undergo to shorten orthodontic treatment duration, followed by teeth vibrators.

Moving towards precision orthodontics: An evolving paradigm shift in the planning and delivery of customized orthodontic therapy

Advances in precision medicine portend similar progress in orthodontics and will be increasingly harnessed to achieve customized treatment approaches and enhance treatment efficiencies. Our goal is to provide a background on emerging advances in computer technologies and biomedicine and highlight their current and likely future applications to precision orthodontics. A review of orthodontically relevant technologies and advances in pertinent biological research was undertaken. Innovations in computer hardware and software, and 3D imaging technologies offer the ability for customized treatment and biomechanical planning that will be more fully realized within the next few decades. These technologies combined with 3D printing are already being applied to customized appliance fabrication such as aligners and retainers. The future prospects for custom fabrication of orthodontic brackets of appropriate material properties and smart devices are highly desirable and compelling goals. Within biomedicine, the fundamental understanding of cartilage growth and bone biology is currently being tested in animal models to modify mandibular growth and modulate tooth movement, respectively. Some of these discoveries will ultimately have clinical applications in orthodontics including for growth modification, accelerating orthodontic tooth movement, and enhancing anchorage or retention of teeth. Additional genomic and proteomic information will add to further customization of orthodontic diagnosis and treatments. Over the coming decades, precision orthodontics will continue to benefit from advances in many fields and will require the integration of advances in technology, and biomedical and clinical research to deliver optimal, efficient, safe, and reproducible personalized orthodontic treatment.

Effect of cyclical forces on orthodontic tooth movement, from animals to humans

Vibration as a non-invasive method is currently available for clinical use with the potential to accelerate the rate of tooth movement in orthodontics. The aim of this review was to evaluate the basic science and clinical literature on the effects of vibration on the axial and appendicular skeleton including the craniofacial bone. Vibration as a dynamic load consisting of high oscillatory forces of low magnitude has shown osteogenic and anti-catabolic effects on bone. These effects have been observed in the craniofacial skeleton including the alveolar bone as increases in sutural width and alveolar bone formation. Animal studies have shown conflicting results on vibration when superposed to orthodontic tooth movement. The effects range from increasing to decreasing the rate of tooth movement. Clinical studies in accelerating the rate of tooth movement have similar findings observed in animal studies. High-frequency oscillatory forces of low magnitude are able to affect bone formation and remodelling. These effects of vibration are primarily anabolic and anti-catabolic in bone, including the craniofacial skeleton and alveolar bone. The effect of vibration on accelerating the rate of orthodontic tooth movement is contradictory. Higher levels of evidence studies have not been able to show an acceleratory effect.

Placebo hypoalgesic effects in pain: Potential applications in dental and orofacial pain management

Placebo and nocebo effects are present within every treatment and intervention, and can be purposefully enhanced and reduced, respectively, in order to improve patients' clinical outcomes. A plethora of research has been conducted on the mechanisms of placebo hypoalgesia and nocebo hyperalgesia in experimental and clinical settings. However, its implications in particular clinical settings such as orthodontic pain management remain underexplored. We conducted a search of the literature regarding placebo analgesia, orthodontic pain management, and orofacial and dental pain. Articles were qualitatively assessed and selected based on the scope of this narrative review. Although no studies investigating the extent of the implications of the placebo and nocebo phenomena in the orthodontic clinical setting were found, we herein present a comprehensive review on the influences of placebo and nocebo effects in experimental and clinical pain management, as well as on the potential for engaging placebo-related endogenous pain modulation for orthodontic pain management. Ethical considerations for the clinical application of placebos are discussed, and future research directions are presented.

The effectiveness of vibrational stimulus to accelerate orthodontic tooth movement: a systematic review

BACKGROUND

In recent years, it has been a hot research topic to accelerate orthodontic tooth movement (OTM) through vibration. This review was therefore aimed to systematically evaluate the available evidences on the efficacy of vibrational stimulus to accelerate OTM.

METHODS

Randomized controlled trials and controlled clinical trials that evaluated the efficacy of vibration on OTM acceleration were searched through electronic and manual search. Two review authors independently conducted the study inclusion, quality assessment and data extraction. The quality of synthesized evidence was assessed according to GRADE system.

RESULTS

Eight clinical trials were included in this systematic review. Four studies found that vibration did not enhance the rate of OTM during alignment phase. Two studies revealed that the use of vibratory stimulation accelerated canine retraction. No deleterious effects including pain perceptions and root resorptions were reported.

CONCLUSIONS

Within the limitations of this review, weak evidence indicates that vibrational stimulus is effective for accelerating canine retraction but not for alignment. The effects of vibration on pain intensity and root resorption during orthodontic treatment are inconclusive. Future high-quality clinical trials are needed before warranting recommendations to clinical application.

Effect of supplemental vibrational force on orthodontically induced inflammatory root resorption: A multicenter randomized clinical trial

INTRODUCTION

A multicenter parallel 3-arm randomized clinical trial was carried out in 1 university and 2 district hospitals in the United Kingdom to investigate the effect of supplemental vibrational force on orthodontically induced inflammatory root resorption (OIIRR) during the alignment phase of fixed appliance therapy.

METHODS

Eighty-one subjects less than 20 years old with mandibular incisor irregularity undergoing extraction-based fixed-appliance treatment were randomly allocated to supplementary (20 minutes a day) use of an intraoral vibrational device (AcceleDent; OrthoAccel Technologies, Houston, Tex) (n = 29), an identical nonfunctional (sham) device (n = 25), or fixed appliances only (n = 27). OIIRR was measured blindly from long-cone periapical radiographs of the maxillary right central incisor taken at the start of treatment and the end of alignment when a 0.019 × 0.025-in stainless steel archwire was placed (mean follow-up, 201.6 days; 95% confidence interval [CI], 188.6-214.6 days). Data were analyzed blindly on a per-protocol basis because losses to follow-up were minimal, with descriptive statistics, 1-way analysis of variance, and univariable and multivariable regression modeling.

RESULTS

Nine patients were excluded from the analysis; they were evenly distributed across the groups. Mean overall OIIRR measured among the 72 patients was 1.08 mm (95% CI, 0.89-1.27 mm). Multivariable regression indicated no significant difference in OIIRR for the AcceleDent (difference, 0.22 mm; 95% CI, -0.14-0.72; P = 0.184) and AcceleDent sham groups (difference, 0.29 mm; 95% CI, -0.15-0.99; P = 0.147) compared with the fixed-appliance-only group, after accounting for patient sex, age, malocclusion, extraction pattern, alignment time, maximum pain experienced, history of dentoalveolar trauma, and initial root length of the maxillary right central incisor. No other side-effects were recorded apart from pain and OIIRR.

CONCLUSIONS

The use of supplemental vibrational force during the alignment phase of fixed appliance orthodontic treatment does not affect OIIRR associated with the maxillary central incisor.

REGISTRATION

ClinicalTrials.gov (NCT02314975).

PROTOCOL

The protocol was not published before trial commencement.

FUNDING

Functional and sham AcceleDent units were donated by the manufacturer; there was no contribution to the conduct or the writing of this study.

Non-pharmacological interventions for alleviating pain during orthodontic treatment

BACKGROUND

Pain is prevalent during orthodontics, particularly during the early stages of treatment. To ensure patient comfort and compliance during treatment, the prevention or management of pain is of major importance. While pharmacological means are the first line of treatment for alleviation of orthodontic pain, a range of non-pharmacological approaches have been proposed recently as viable alternatives.

OBJECTIVES

To assess the effects of non-pharmacological interventions to alleviate pain associated with orthodontic treatment.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 6 October 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2016, Issue 9), MEDLINE Ovid (1946 to 6 October 2016), Embase Ovid (1980 to 6 October 2016) and EThOS (to 6 October 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing a non-pharmacological orthodontic pain intervention to a placebo, no intervention or another non-pharmacological pain intervention were eligible for inclusion. We included any type of orthodontic treatment but excluded trials involving the use of pre-emptive analgesia or pain relief following orthognathic (jaw) surgery or dental extractions in combination with orthodontic treatment. We excluded split-mouth trials (in which each participant receives two or more treatments, each to a separate section of the mouth) and cross-over trials.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed risk of bias and extracted data. We used the random-effects model and expressed results as mean differences (MD) with 95% confidence intervals (CI). We investigated heterogeneity with reference to both clinical and methodological factors.

MAIN RESULTS

We included 14 RCTs that randomised 931 participants. Interventions assessed included: low-level laser therapy (LLLT) (4 studies); vibratory devices (5 studies); chewing adjuncts (3 studies); brain wave music or cognitive behavioural therapy (1 study) and post-treatment communication in the form of a text message (1 study). Twelve studies involved self-report assessment of pain on a continuous scale and two studies used questionnaires to assess the nature, intensity and location of pain.We combined data from two studies involving 118 participants, which provided low-quality evidence that LLLT reduced pain at 24 hours by 20.27 mm (95% CI -24.50 to -16.04, P < 0.001; I² = 0%). LLLT also appeared to reduce pain at six hours, three days and seven days.Results for the other comparisons assessed are inconclusive as the quality of the evidence was very low. Vibratory devices were assessed in five studies (272 participants), four of which were at high risk of bias and one unclear. Chewing adjuncts (chewing gum or a bite wafer) were evaluated in three studies (181 participants); two studies were at high risk of bias and one was unclear. Brain wave music and cognitive behavioural therapy were evaluated in one trial (36 participants) assessed at unclear risk of bias. Post-treatment text messaging (39 participants) was evaluated in one study assessed at high risk of bias.Adverse effects were not measured in any of the studies.

AUTHORS' CONCLUSIONS

Overall, the results are inconclusive. Although available evidence suggests laser irradiation may help reduce pain during orthodontic treatment in the short term, this evidence is of low quality and therefore we cannot rely on the findings. Evidence for other non-pharmacological interventions is either very low quality or entirely lacking. Further prospective research is required to address the lack of reliable evidence concerning the effectiveness of a range of non-pharmacological interventions to manage orthodontic pain. Future studies should use prolonged follow-up and should measure costs and possible harms.

Current advances in orthodontic pain

Orthodontic pain is an inflammatory pain that is initiated by orthodontic force-induced vascular occlusion followed by a cascade of inflammatory responses, including vascular changes, the recruitment of inflammatory and immune cells, and the release of neurogenic and pro-inflammatory mediators. Ultimately, endogenous analgesic mechanisms check the inflammatory response and the sensation of pain subsides. The orthodontic pain signal, once received by periodontal sensory endings, reaches the sensory cortex for pain perception through three-order neurons: the trigeminal neuron at the trigeminal ganglia, the trigeminal nucleus caudalis at the medulla oblongata and the ventroposterior nucleus at the thalamus. Many brain areas participate in the emotion, cognition and memory of orthodontic pain, including the insular cortex, amygdala, hippocampus, locus coeruleus and hypothalamus. A built-in analgesic neural pathway—periaqueductal grey and dorsal raphe—has an important role in alleviating orthodontic pain. Currently, several treatment modalities have been applied for the relief of orthodontic pain, including pharmacological, mechanical and behavioural approaches and low-level laser therapy. The effectiveness of nonsteroidal anti-inflammatory drugs for pain relief has been validated, but its effects on tooth movement are controversial. However, more studies are needed to verify the effectiveness of other modalities. Furthermore, gene therapy is a novel, viable and promising modality for alleviating orthodontic pain in the future.