Accelerate Tooth Movement Research Articles

Effect of vibration on orthodontic tooth movement in a double blind prospective randomized controlled trial

The purpose of the present study was to investigate the effect of vibration on orthodontic tooth movement and safety assessment based on our previous basic research in animal experiments. A double-blind prospective randomized controlled trial using split-mouth design was conducted in patients with malocclusion. The left and right sides of maxillary arch were randomly assigned to vibration (TM + V) and non-vibration (TM) groups. After leveling, vibrations (5.2 ± 0.5 g-forces (gf), 102.2 ± 2.6 Hertz (Hz)) were supplementary applied to the canine retracted with 100 gf in TM + V group for 3 min at the monthly visit under double-blind fashion, and the canine on the other side without vibration was used as TM group. The amount of tooth movement was measured blindly using a constructed three-dimensional dentition model. The amount of canine movement per visit was 0.89 ± 0.55 mm in TM group (n = 23) and 1.21 ± 0.60 mm in TM + V group (n = 23), respectively. There was no significant difference of pain and discomfort, and root resorption between the two groups. This study indicates that static orthodontic force with supplementary vibration significantly accelerated tooth movement in canine retraction and reduced the number of visits without causing side effects.

Periodontal ligament cells under mechanical force regulate local immune homeostasis by modulating Th17/Treg cell differentiation.

Improper orthodontic force often causes root resorption or destructive bone resorption. There is evidence that T helper 17 (Th17) cells and regulatory T (Treg) cells may be actively involved in bone remodeling during tooth movement. In a combination of in vitro and in vivo studies, we investigated the effect of human periodontal ligament cells (hPDLCs) on Th17/Treg cells under different orthodontic forces and corticotomy. hPDLCs were cultured in vitro and subjected to different mechanical forces. The expression of interleukin (IL)-6 and transforming growth factor (TGF)-β in the supernatant and the mRNA levels of hypoxia inducible factor (HIF)-1α, Notch1, and TGF-β in hPDLCs were investigated. Supernatants were collected and co-cultured with activated CD4+T cells, and the differentiation of Th17/Treg cells was analyzed by flow cytometry. We also established an animal model of tooth movement with or without corticotomy. The tooth movement distance, alveolar bone height, and root resorption were analyzed using micro-computed tomography. Expression of interleukin (IL)-17A, forkhead Box P3 (Foxp3), and IL-6 were analyzed using immunohistochemistry, while osteoclasts were evaluated by tartrate-resistant acid phosphatase (TRAP) staining. The mRNA levels of IL-17A, IL-6, Foxp3, IL-10, HIF-1α, notch1, and C-X-C motif chemokine ligand 12 (CXCL12) in alveolar bone and gingiva were investigated. Heavy force repressed cell viability and increased the mortality rate of hPDLCs; it also improved the expression of IL-6, declined the expression of TGF-β, and promoted the mRNA expression level of HIF-1α. The expression of TGF-β and Notch1 mRNA decreased and then increased. The supernatant of hPDLCs under heavy force promotes the polarization of Th17 cells. The heavy force caused root resorption and decreased alveolar bone height and increased the positive area of IL-17A immunohistochemical staining and the expression of IL-17A, IL-6, HIF-1α, and Notch1 mRNA. Corticotomy accelerated tooth movement, increased the proportion of Foxp3-positive cells, and up-regulated the expression of Foxp3, IL-10, and CXCL12 mRNA. During orthodontic tooth movement, the heavy force causes root resorption and inflammatory bone destruction, which could be associated with increased expression of Th17 cells and IL-6. Corticotomy can accelerate tooth movement without causing root resorption and periodontal bone loss, which may be related to the increased expression of Treg cells. Altogether, this report provides a new perspective on the prevention of inflammatory injury via the regulation of Th17/Treg cells in orthodontics.

The Perception of Adults and Adolescents of Undergoing and Paying for Tooth Movement Acceleration Procedures in Turkey.

The aim of this study is to evaluate the opinions of adolescents and adults regarding nonconventional methods and their associated payment options in Turkey. A total of 183 subjects were asked to complete a questionnaire to evaluate their perception of various nonconventional acceleration methods: corticotomy, piezocision, micro-osteoperforation, vibration, drug injection, and customized appliances. The questionnaire also investigated how willing the patients would be to pay more and how much more they would accept to reduce the treatment time. About 38.7% of the adolescents and 44.4% of the adults were willing to undergo an additional procedure, and 59.6% of both groups chose customized appliances as their first preference as a way of accelerating the treatment process. About 45.4% of the total participants were neutral about paying more to reduce treatment time. Those patients who were willing to pay more accepted a maximum increase of only 10% even if that meant a 50% decrease in treatment time. Adults were slightly less tolerant of the duration of orthodontic treatment than adolescents and were more likely to undergo additional procedures and pay more for a shorter treatment time. In addition, the invasiveness of each procedure was the primary factor given when choosing an acceleration method, rather than its reduction rate.

Comparison Between the Effect of Low-Energy Laser Application and Piezocision on Acceleration of Orthodontic Tooth Movement


 ABSTRACT the aim of the study was to study the effectiveness of Low Energy Laser Application or piezocisions in accelerating tooth movement, during canine retraction, compared to conventional canine retraction. Patients and Methods: A split mouth study design was done with two groups A and B. Each group confined 10 patients; in each patient one side was used as a control side and the contralateral side received either low-level laser therapy (LLLT) (group A) or piezocisions (group B). The evaluation data was gathered by Intra-oral measurements directly, every 2 weeks, over a 3 months retraction period. Results: Statistical analysis using Repeated measure ANOVA test was used to compare between more than two groups in related samples. Paired sample t-test was used to compare between two groups in related samples. Independent sample t-test was used to compare between two groups in non-related samples. direct intra-oral measurements from Group A illustrated that there was a statistically significant difference between the study and control sides (p<0.001) a total of 4.19 ± 0.5 mm canine retraction has been achieved in the low-level laser therapy (LLLT) assisted canine retraction side versus a 2.83 ± 0.2 mm total canine retraction in the control side. which was statistically significant. Group B illustrated that there was a statistically significant difference between the study and control sides ( p<0.001) that a total of 3.65± 0.4 mm canine retraction has been achieved in the piezocisions assisted canine retraction side versus a 2.79± 0.2 mm total canine retraction in the control side which was a highly statistically significant difference Conclusion: low-level laser therapy (LLLT) and Piezocisions techniques accelerated the rate of canine retraction during orthodontic treatment, with the low-level laser therapy (LLLT) being slightly more effective.

Photobiomodulation and its Effect on Stability of Orthodontic Mini-implants: A Systematic Review and Meta-analysis of Randomised Controlled Trials

Introduction: The influence of Photobiomodulation (PBM) in the field of orthodontics has been of recent interest. PBM has a promising effect on acceleration of tooth movement, alleviation of pain during orthodontic treatment and Mini-Implant (MI) stability. Aim: The aim of this review was to systematically report on the effectiveness of PBM on the stability of orthodontic MI. Materials and Methods: Literature search was conducted in five electronic databases for human trials published between January 2000 to February 2021 on the effectiveness of PBM therapy for stability of orthodontic MI. This systematic review was conducted during January 2021 and February 2021. Cochrane review manager software (Revman version 5.4) and Cochrane Risk Of Bias (ROB) 2 tool were used for bias assessment. The primary outcome measured was the stability of MI using Resonance Frequency Analysis (RFA) or Periotest Value (PTV). The secondary outcomes measured were pain and inflammation around the peri-implant area. Also, Interleukin-1β (IL-1β) was also measured in gingival crevicular fluid. Results: A total of six Randomized Controlled Trials (RCTs) were included in the review. Out of the 6 studies, 2 showed low Risk Of Bias (ROB) whereas 3 showed some concerns and 1 showed high ROB. Quantitative analysis was done for 4 studies with a random effects model to assess the MI stability measured by periotest at 30 days and 60 days. A significant mean difference of -3.31 (95% CI-5.15,-1.47) between PBM and controls for mini-implant stability at 30 days and a significant mean difference of -3.47 (95% CI-4.58, -2.36) between PBM and controls at 60 days with low heterogeneity was obtained. Three studies reported on the pain response after PBM and both groups showed no significant difference. A decrease in gingival inflammation was reported in one study whereas other study showed no significant change in IL-1ß in gingival crevicular fluid. Conclusion: Majority of the studies included in this review reported improved secondary stability with PBM. The low heterogeneous nature of the quantitative studies also supports the data obtained. However, the results should be concluded with caution.

Comparison of Rate of Tooth Movement, Root Resorption and Pulp Vitality during En masse Anterior Retraction with Micro-osteoperforation and Low Level Laser Therapy: A Randomised Clinical Trial

Introduction: Micro-osteoperforation (MOP) and Low Level Laser Therapy (LLLT) are rapidly gaining popularity in clinical practice due their proven success in accelerating tooth movement and acceptable patient compliance. However, literature shows an inconsistent and variable evidence of their iatrogenic effects on the root and pulp due to biological variations of the samples chosen by the previously studies. Aim: To evaluate and compare the rate of tooth movement, changes in amount of external root resorption and pulp vitality in teeth during en masse anterior retraction associated with MOP and LLLT using split mouth technique. Materials and Methods: This was a double blinded, single center split mouth randomised clinical trial conducted at Faculty of Dental Sciences, MS Ramaiah University of Applied Sciences, Bangalore, Karnataka, India from March 2019 to October 2019. Total of 11 patients with bimaxillary dentoalveolar protrusion which required all four first premolar extractions were included in the study. Nickel Titanium (NiTi) closed coil springs were used for en masse retraction in upper and lower arches with force of 150g per side. Root resorption of all anterior teeth was evaluated using Cone Beam Computed Tomography systems (CBCT) and pulp vitality was checked using cold test after 4 months. The data was entered in Microsoft excel and the Statistical Package for Social Sciences software (SPSS) version 18.5 (SPSS Inc, Chicago) software was used for data entry and statistical analysis. A p-value of less than 0.05 was considered as statistically significant. Results: Total of 11 patients in which 9 were females and 2 males aged between 18-30 years with mean age 19±4.21 year, participated in this trial. LLLT (4 mm) and MOP (4.05 mm) showed similar performance in acceleration of tooth compared to each other. The overall root resorption was more in the experimental groups (LLLT- 2.60 mm, MOP- 2.84 mm) compared to the allotted controls. However, the canine showed less root resorption in both the experimental groups compared to the control. The overall root resorption was similar in both the experimental groups. The canine in LLLT group (0.30 mm) showed less root resorption compared to canine in MOP group (0.59 mm). There was no change in the pulp vitality status in both the experimental groups and the control groups. Conclusion: The overall root resorption in a given quadrant increases with increased rate of tooth movement. The tooth which was subjected to acceleratory orthodontic technique showed less root resorption compared to control. The tooth subjected to LLLT showed less root resorption as compared to the tooth subjected to MOP.

Evaluation of exaggerated claims in the abstracts of systematic reviews reporting accelerated orthodontic tooth movement: a meta research analysis

Abstract Background The latest trend in scientific literature review is to scrutinise the practices of false or biased reporting of findings, which is rightly termed as ‘spin’. In recent years, accelerated tooth movement has gained attention from the orthodontic community, but the findings still remain unclear and controversial. Objectives To estimate the frequency of distorted claims and over-interpretation of abstracts of systematic reviews related to accelerated orthodontic tooth movement. The objective was to differentiate the type of claim and to determine its prevalence. Methods A literature search was performed using the Cochrane library and the top five most prominent orthodontic journals for systematic reviews on accelerated orthodontics were identified by applying appropriate key words. According to pre-set selection criteria, only systematic reviews published between January 2010 and September 2021 were included. The selected articles were scrutinised for the assigned exclusion criteria. The articles were finally scanned for false claims by two independent reviewers. The identified claims fell into either the categories of misleading interpretation, misleading reporting or misleading extrapolation. The obtained data were tabulated and analysed using the one-way ANOVA statistical test to indicate the difference between the different types of reported claims. Results There were 98 systematic reviews identified in total, of which 59 articles met the selection criteria and 39 articles were excluded. Of the 59 included articles, 38 systematic reviews had exaggerated claims. Twenty-two of the reported claims came under the misleading reporting category, 10 fell under the misleading interpretation category and 6 came under the misleading extrapolation category. The difference noted between the reporting prevalence of different types of claim was statistically significant (P < 0.001). In misleading reporting, it was noted that most of the systematic reviews refrained from reporting the adverse effects of treatment. Conclusion The prevalence of exaggerated claims is high in the abstracts of systematic reviews related to accelerated orthodontic tooth movement. It is recommended that a clinician critically assess the claims presented in systematic reviews which are considered to be the hallmark articles of evidence-based practice. Orthodontists should be careful when applying the findings in clinical practice.

Platelet concentrates in periodontics: review of in vitro studies and systematic reviews

Clot formation is the first step of the healing process, and clinical procedures always find ways to stabilize this clot better. Platelets play a significant role in clot formation, and Platelet Concentrates (Pc) are an abundant reservoir of platelets. This article aims to review the in vitro research and systematic reviews on PCs that are currently available. Broadly, PCs mainly include Platelet-rich plasma and platelet-rich fibrin. PCs are an excellent source for growth factors such as PDGF-AA, TGF β1, VEGF, EGF, and IGF. Numerous systematic reviews and meta-analyses have analyzed the clinical application of PCs in various periodontal procedures. In alveolar ridge preservation, PCs are known to reduce postoperative pain, edema, trismus, and inflammation. PRF had shown significant improvement in achieving root coverage and recession depth reduction. PCs exhibited a positive influence on CAL gain when used as an adjunct to OFD in treating infra-bony defects. Pcs have a positive effect on bone maturation in the short term. Besides, PCs can be used in regenerative endodontics, treatment of medication-related osteoradionecrosis of Jaw (MRONJ), and accelerating tooth movement. In conclusion, PCs positively affect soft tissue healing, while their role in hard tissue healing is still unclear.

Orthodontic root resorption associated with surgical adjunctive procedures for accelerating tooth movement: a systematic review of randomised controlled trials

Abstract Introduction The present systematic review assesses the literature which identifies an association between surgical adjunctive procedures for accelerating tooth movement (SAPATM) during orthodontic therapy and orthodontically induced external root resorption (OIERR). By determining the level of association, the results may provide clinical evidence for minimising the deleterious effects of orthodontic tooth movement. Methods Electronic databases including Medline, PubMed, Embase, Scopus, CINAHL, Worldcat, OpenGrey, and the Cochrane Library were searched and followed by further searches from citations of included articles. Searches were undertaken with no restrictions on year, publication status, nor language. The selection criteria included randomised controlled trials (RCTs) conducted using surgical procedures to accelerate orthodontic therapy in conjunction with fixed orthodontic appliances on human patients. The quality of the included studies was assessed using the Cochrane Risk of Bias (RoB) Tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Inter-rater agreement of the review authors was used for the inclusion of primary articles, RoB assessment and evaluation of the quality of evidence (GRADE) and was calculated using Cohen’s kappa statistic. Results A total of 1118 articles were retrieved in the initial search. After the review process, 13 article trials met the inclusion criteria. Sample sizes ranged from 20 to 52 patients. Two studies showed a statistically significant reduction in OIERR, with a third showing both an increase and decrease of OIERR on different roots of the same maxillary molar tooth. A significant decrease in treatment time was shown by four studies, while six studies showed increased tooth movement. All included studies were classified as having low to minor concerns of bias and a low quality of evidence. Conclusions There is an apparent shortage of well-designed and reported RCTs on the effect of SAPATM on OIERR. However, there is some evidence to suggest OIERR is reduced following SAPATM. The use of SAPATM is also shown to increase tooth movement and reduce overall treatment time, but its benefits may be considered limited to the initial post-operative period.

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

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

Wilkodontics: A Meteoric Rise to Faster Orthodontic Treatments

A tremendous amount of advances has been made in the field of dentistry in the past few decades. In spite of these advances, the average orthodontic treatment lasts 1.5 to 3 years. "Wilkodontics," often called Periodontally Accelerated Osteogenic Orthodontics (PAOO) is a procedure that helps in accelerating tooth movement as well as in providing an increase for rendering extensive dental services and care to the patients in bone activation through selective decortication and osteotomies as well as alveolar augmentation using a particulate bone graft. Thus, thisThis article attempts to review the main indications, contraindications, and modifications of wilkodontics.

CBCT assessment of mandibular incisor orthodontically induced root resorption during accelerated tooth movement via low level Laser therapy

CBCT assessment of mandibular incisor orthodontically induced root resorption during accelerated tooth movement via low level Laser therapy

Orthodontic root resorption

External apical root resorption (EARR) is one of the most frequently reported iatrogenic side effects of orthodontic movement. Nevertheless, no robust and unequivocal scientific evidence is yet available in the literature regarding the clinical and biological factors that trigger EARR. The purpose of the present position paper is to provide clinicians, residents, and investigators a summary of our current understanding about root resorption caused by orthodontic tooth movement, based on up-to-date available scientific evidence.Morphological, structural, biomechanical, and biological differences account for predisposing the apical third to EARR compared to other root surfaces during orthodontic treatment. In addition, a relevant number of patient and treatment-related factors increase risk of EARR. The main patient-related factors are reviewed and discussed: genetic factors, tooth anatomy, demographic factors, malocclusion factors, previous endodontic treatment, medical history, short root anomaly. Similarly, the influence of treatment-related factors are analyzed with regard to the effect of: biomechanical factors, type of orthodontic appliance, adjunctive therapies to accelerate tooth movement, early treatment, maxillary expansion, teeth extractions, the duration of treatment and the amount of apical displacement. Clinical management of EARR from pre-treatment records to the monitoring strategy as well as recommendations for the post orthodontic-treatment period are presented as a guide for the clinician.Despite years of studies, we still do not fully understand EARR, but the future is promising. True three-dimensional imaging with higher resolution and low radiation, and predictive tools towards an earlier detection without radiographs, will mark future developments in the field of EARR in orthodontics.

Stem Cells and Dentofacial Orthodontic Treatment Potential

Background: In recent years, stem cell therapy has become a very promising and advanced scientific research topic. With advanced technology in tissue engineering, the development of this approach has evolved with great expectations.Methods: This article is focused on the discovery of stem cells and their potential application in dentofacial orthodontic treatment. For craniofacial deformities, stem cell-based therapy has been applied as a part of a tissue engineering approach to regenerate bone and tissues to reconstruct the deformities. With a limitation of tissue defects, several stem cells could be great candidates for the treatment.Conclusions: Stem cell-based therapy could be applied for TMJ regeneration with great potential for the development of scaffold regenerative materials. Current evidence demonstrates the potential of stem cellbased therapy for regenerate cementum, collagen and alveolar bone for the benefit of accelerated tooth movement, increased envelope of discrepancy and improved posttreatment stability.Practical implications: However, there is a need for more in vivo and clinical trials for stem cell-based therapy to be used as a standard treatment.

Frontier in Orthodontics – Dental Tooth Movement Acceleration

There is an increased tendency for researchers to focus on the methods accelerating tooth movement due to the high demand by adult patients for short orthodontic treatment duration. Unfortunately, longer orthodontic treatment duration poses certain risks such as increase likelihood for caries, gingival recession, and root resorption. This also leads to a higher demand to identify the methods to increase tooth movement with minimum possible side-effects. The purpose of this review is to describe the success approaches in acceleration of tooth movement and to highlight their pros and cons. Biological methods of tooth movement have shown that cytokines, RANKL show good results for accelerating tooth movement and raloxifene is best used for retention as it decreases relapse. Osteotomy and corticotomy are useful in increasing the rate of tooth movement but are invasive. Osteoperforations is less invasive and can give good results for acceleration of orthodontic tooth movement.

Intermittent vibratory stimulation to accelerate tooth movement: A clinical study

Vibratory stimulus is non-invasive and non-pharmacologic method for acceleration of Orthodontic tooth movement in adult patients. As powered toothbrush can provide cheaper alternative to Acceledent (a patent and expensive device) it was decided to evaluate the effectiveness of vibratory stimulation from powered toothbrush as a method of accelerating individual canine retraction.Sample consisted of 24 patients undergoing fixed Orthodontic treatment, in whom separate canine retraction was planned after extraction of all first premolars using NiTi closed coil spring. Force was standardized as 150 grams and checked at each appointment using Dontrix gauge. Following split mouth study design, right side was the experimental side where patients were asked to apply the vibratory stimulus through powered tooth brush (133Hz frequency) for 6 minutes (3 minutes labially and 3 minutes palatally) three times daily at regular intervals for a period of 3 months. Study models were taken at T0 (start of canine retraction), T1 (after 1st month), T2 (after 2nd month) and T3 (after 3rd month). Mean amount of canine movement and molar movement with respect to 3rd palatine rugae was measured on Digimizer software on both the sides for different time intervals.Statistically significant increase in canine movement was seen for total canine movement (T0-T3), movement from T0-T1 and from T2-T3. There was statistically insignificant difference in mesial movement of molars for different time intervals.There was an increased rate of canine movement on the side of vibratory stimulation (right side) in comparison to the control side (left side) for all time intervals and can be used to decrease treatment time in adults.

Surgical acceleration of tooth movement: a systematic review to optimize communication between the orthodontist, the oral surgeon and the patient

This systematic review aims to compare conventional corticotomy with minimally-invasive protocols (MIP). Electronic database, in MEDLINE and CENTRAL, and hand search were performed. Randomized controlled trials (RCTs) and randomized split-mouth designed studies (RSMSs) were selected for inclusion, reporting either the use of a corticotomy procedure or a MIP. The main outcomes were the rate/velocity of tooth movement, type of tooth movement observed, loss of anchorage, periodontal indexes, inflammatory mediators, root resorption, patient's pain experience, impact on the quality of life, and satisfaction. Twenty-two papers were included for the qualitative synthesis, from which ten RCTs and twelve RSMSs. Eighteen of them compared a conventional orthodontic treatment without and with a surgical adjunctive procedure, two with conventional corticotomy and sixteen with a MIP (piezocision, micro-osteoperforations (MOPs) or interseptal bone reduction). Four trials compared a surgical procedure to another one. Corticotomy, piezocision and MOPs are likely to accelerate tooth movement, in decreasing order. Pain is reported to be higher in experimental groups only on the first day after surgery. Patient satisfaction is high after surgical procedures. Loss of anchorage, periodontal indexes, or root resorption occurrence show no differences between groups. Corticotomy stands as the gold-standard procedure for surgically-assisted orthodontics, but piezocision appears as a good compromise solution as well as MOPs, in a lesser extent. MIP are known to accelerate tooth movement only during the first three months.

Autophagy Induces Expression of IL-6 in Human Periodontal Ligament Fibroblasts Under Mechanical Load and Overload and Effects Osteoclastogenesis in vitro.

Objective: Autophagy is an important cellular adaptation mechanism to mechanical stress. In animal experiments, inhibition of autophagy during orthodontic tooth movement triggered increased expression of inflammation-related genes and decreased bone density. The aim of this study was to investigate how autophagy affects cytokine levels of interleukin 6 (IL-6) in human periodontal ligament (hPDL) fibroblasts under mechanical pressure and the resulting influence on osteoblast communication.Methods: hPDL fibroblasts were subjected to physiologic mechanical load, constant overload, or rapamycin treatment for 16 to 24 h ± autophagy inhibitor 3-MA. Autophagosomes were quantified by flow cytometry. Gene expression of il-6 as well as IL-6 levels in the supernatant were determined with rtPCR and ELISA. To investigate the influence of mechanically-induced autophagy on cell-cell communication, an osteoblast-culture was subjected to supernatant from stimulated hPDL fibroblasts ± soluble IL-6 receptor (sIL-6R). After 24 h, osteoprotegerin (opg) and receptor activator of nuclear factor κB ligand (rankl) gene expressions were detected with rtPCR. Gene expression of a disintegrin and metalloproteinases (adam) 10 and 17 in stimulated hPDL fibroblasts was examined via rtPCR.Results: Autophagy was induced by biomechanical stress in hPDL fibroblasts in a dose-dependent manner. Mechanical load and overload increased IL-6 expression at gene and protein level. Autophagy inhibition further enhanced the effects of mechanical stimulation on IL-6 expression. Mechanical stimulation of hPDL fibroblasts downregulated adam10 and adam17 expressions. Inhibition of autophagy had stimulus-intensity depending effects: autophagy inhibition alone or additional application of physiological stress enhanced adam10 and adam17 expressions, whereas mechanical overload had adverse effects. Osteoblasts showed significantly reduced opg expression in the presence of supernatant derived of hPDL fibroblasts treated with autophagy inhibitor and sIL-6R.Conclusion: IL-6 levels were increased in response to pressure in hPDL fibroblasts, which was further enhanced by autophagy inhibition. This caused a decrease in opg expression in osteoblasts. This may serve as an explanatory model for accelerated tooth movement observed under autophagy inhibition, but may also represent a risk factor for uncontrolled bone loss.

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

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. 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. 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. 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.

Lasers in Orthodontics

Laser technique now is widely applied in orthodontic treatment and proved to have many benefits. Soft tissue lasers can be used to perform gingivectomy, frenectomy and surgical exposure of tooth with less bleeding and swelling, improved precision, reduced painand less wound contraction. Other laser applications include enamel etching and bonding andbracket debonding. Lower level lasers have the potential effects of pain control and accelerating tooth movement. Clinicians must be aware of the safety issues and risks associated with laser and receive proper training before the laser treatment is started.