Evaluation of the acceleration, skeletal and dentoalveolar effects of low-level laser therapy combined with fixed posterior bite blocks in children with skeletal anterior open bite: A three-arm randomised controlled trial

Clinical and preclinical evidence on the bioeffects and movement-related implications of photobiomodulation in the orthodontic tooth movement: A systematic review

Photobiomodulation (PBM) has been demonstrated as a non-invasive and painless technique with great potential to accelerate orthodontic tooth movement (OTM). However, there is a great inconsistency among PBM protocols and reported outcomes, probably due to the poor translatability of preclinical knowledge into early clinical practice. Hence, this review aims to fill this gap by establishing the state-of-the-art on both preclinical and clinical applications of PBM, and by comprehensively discussing the most suitable stimulation protocols described in the literature. This review was conducted according to PRISMA guidelines. A bibliographic search was carried out in the PubMed, Scopus and Cochrane databases using a combination of keywords. Only studies written in English were eligible and no time limit was applied. A total of 69 studies were selected for this review. The revised literature describes that PBM can effectively reduce orthodontic treatment time and produce analgesic and anti-inflammatory effects. We found that PBM of 640 ± 25, 830 ± 20 and 960 ± 20 nm, delivered at a minimum energy density per irradiation point of 5 J/cm2 daily or every other day sessions is robustly associated with increased tooth movement rate. Pain relief seems to be achieved with lower irradiation doses compared to those required for OTM acceleration. For the first time, the bioeffects induced by PBM for the acceleration of OTM are comprehensively discussed from a translational point of view. Collectively, the evidence from preclinical and clinical trials supports the use of PBM as a coadjuvant in orthodontics for enhancing tooth movement and managing treatment-associated discomfort. Overall, the revised studies indicate that optimal PBM parameters to stimulate tissue remodelling are wavelengths of 830 ± 20 nm and energy densities of 5-70 J/cm2 applied daily or every other day can maximize the OTM rate, while lower doses (up to 16 J/cm2 per session) delivered in non-consecutive days seem to be optimal for inducing analgesic effects. Future research should focus on optimizing laser parameters and treatment protocols customized for tooth and movement type. By fine-tuning laser parameters, clinicians can potentially reduce treatment times, improve patient comfort and achieve more predictable outcomes, making orthodontic care more efficient and patient-friendly, thus consolidating PBM usage in orthodontics.

Periodontal considerations during orthodontic intrusion and extrusion in healthy and reduced periodontium

In patients with advanced periodontal disease, pathological tooth migration may occur, which may require subsequent orthodontic treatment for both aesthetic and functional purposes. When planning orthodontic treatment mechanics, intrusive or extrusive forces are frequently indicated. Understanding tissue reactions during these movements is essential for clinicians when devising a comprehensive orthodontic-periodontal treatment plan. This knowledge enables clinicians to be fully aware of and account for the potential effects on the surrounding tissues. The majority of our understanding regarding the behavior of periodontal tissues in both healthy and compromised periodontal conditions is derived from animal studies. These studies offer the advantage of conducting histological and other assessments that would not be feasible in human research. Human studies are nevertheless invaluable in being able to understand the clinically relevant response elicited by the periodontal tissues following orthodontic tooth movement. Animal and human data show that in dentitions with reduced periodontal support, orthodontic intrusion of the teeth does not induce periodontal damage, provided the periodontal tissues do not have inflammation and plaque control with excellent oral hygiene is maintained. On the contrary, when inflammation is not fully controlled, orthodontic intrusion may accelerate the progression of periodontal destruction, with bacterial plaque remnants being displaced subgingivally, leading to further loss of attachment. Orthodontic extrusion, on the other hand, does not seem to cause further periodontal breakdown in dentitions with reduced periodontal support, even in cases with deficient plaque control. This is attributed to the nature of the tooth movement, which directs any plaque remnants coronally (supragingivally), reducing the risk of adverse effects on the periodontal tissues. This specific type of tooth movement can be leveraged to benefit periodontal conditions by facilitating the regeneration of lost hard and soft periodontal tissues in a coronal direction. As a result, orthodontic extrusion can be employed in implant site development, offering an advantageous alternative to more invasive surgical procedures like bone grafting. Regardless of the tooth movement prescribed, when periodontal involvement is present, it is essential to prioritize periodontal therapy before commencing orthodontic treatment. Adequate plaque control is also imperative for successful outcomes. Additionally, utilizing light orthodontic forces is advisable to achieve efficient tooth movement while minimizing the risk of adverse effects, notably root resorption. By adhering to these principles, a more favorable and effective combined orthodontic-periodontal approach can be ensured. The present article describes indications, mechanisms, side effects, and histological and clinical evidence supporting orthodontic extrusion and intrusion in intact and reduced periodontal conditions.

Patient-reported outcomes during accelerating the en-masse retraction of the upper anterior teeth using low-intensity electrical stimulation: a randomized controlled trial

BACKGROUND

Low-intensity electrical stimulation (LIES) is considered a relatively recent technology that has received little attention in orthodontics as a method of acceleration. This study aimed to evaluate patient-reported outcome measures when LIES is used to accelerate the en-masse retraction of the upper anterior teeth.

MATERIALS AND METHODS

The sample consisted of 40 patients (8 males, 32 females; mean age 21.1 ± 2.3 years), with Class II division I malocclusion who required extraction of the first premolars to retract upper anterior teeth. They were randomly assigned to the LIES group (n = 20) and the conventional en-masse retraction group (CER; n = 20). Patient responses regarding pain, discomfort, burning sensation, swelling, chewing difficulty, speech difficulty, and painkillers' consumption were recorded at these nine assessment times: 24 h (T1), 3 days (T2), and 7 days (T3) after force application, then in the second month after 24 h (T4), 3 days (T5), and 7 days (T6) of force re-activation, and finally after 24 h (T7), 3 days (T8), and 7 days (T9) of force re-activation in the third month.

RESULTS

The mean values of pain perception were smaller in the LIES group than those in the CER group at all assessment times with no statistically significant differences between the two groups except during the second and third months (T5, T6, T8, and T9; P < 0.005). However, discomfort mean values were greater in the LIES group with significant differences compared to CER group during the first week of the follow-up only (T1, T2, and T3; P < 0.005). Burning sensation levels were very mild in the LIES group, with significant differences between the two groups at T1 and T2 only (P < 0.001). Speech difficulty was significantly greater in the LIES group compared to CER group at all studied times (P < 0.001). High levels of satisfaction and acceptance were reported in both groups, without any significant difference.

CONCLUSION

Both the LIES-based acceleration of en-masse retraction of upper anterior teeth and the conventional retraction were accompanied by mild to moderate pain, discomfort, and chewing difficulty on the first day of retraction. These sensations gradually decreased and almost disappeared over a week after force application or re-activation.

TRIAL REGISTRATION

ClinicalTrials.gov, ClinicalTrials.gov, NCT05920525. Registered 17 June 2023 - retrospectively registered, http://clinicaltrials.gov/study/NCT05920525?term=NCT05920525&rank=1 .

Evaluation of Patient-Reported Outcome Measures (PROMs) Associated With the Acceleration of Canine Retraction by Piezosurgery in Comparison With Low-Level Laser Therapy: A Three-Arm Randomized Controlled Clinical Trial

Background and objectives Recently, both surgical and non-surgical interventions have gained popularity in accelerating orthodontic tooth movement, but there is no randomized controlled trial (RCT) comparing both modalities in terms of patient-reported outcome measures (PROMs) during maxillary canine retraction. Therefore, this trial aimed to assess the PROMs associated with either low-level laser therapy (LLLT) or piezocision-assisted acceleration in the context of maxillary canine retraction. Materials and methods This was a single-blinded, single-center, three-arm RCT. A total of 54 patients (12 males, 42 females, mean age 20.65 ± 2.85) whose treatment needed upper-first-premolar extraction to facilitate canine retraction were enrolled and randomly divided into three groups: piezocision group (PG), LLLT group (LLLTG), and the control group (CG). Standardized questionnaires using a visual analog scale were distributed to patients at five assessment times: 1 (T1), 3 (T2), 7 (T3), 14 (T4), and 28 days following the canine retraction initiation (T5). The patients' pain, discomfort, swelling, chewing difficulty, satisfaction, and acceptance were recorded. Results Regarding pain and discomfort, the levels were significantly lower in the LLLTG during the first two weeks of canine retraction compared to the other two groups (p<0.017). At the same time, these levels were significantly greater in the PG than the CG in the first week of canine retraction (p<0.017). Patients in the PG had a "mild to moderate" perception of swelling at T1 and T2, which was significantly different than that of the other two groups (p<0.001). Regarding chewing difficulty, the levels in the LLLTG were significantly lower than those in PG at the first three assessment times (p<0.017). Patients' satisfaction with canine speed was significantly greater in the intervention groups compared to the CG (p<0.001). In contrast, no statistically significant differences were found between the three groups regarding satisfaction with gum appearance surrounding the canine (p=0.061) and acceptance (p=0.125). Conclusion The LLLT-assisted canine retraction was associated with significantly lower negative patient-reported outcomes during the first two weeks of retraction than piezocision-assisted retraction. However, the levels of pain and discomfort were significantly greater in the piezocision-assisted retraction group than those in the conventional canine retraction group, which in turn were greater than those with the LLLT-assisted canine retraction group during the first week of retraction. Patient satisfaction and acceptance were high with both piezocision and LLLT interventions.

Assessment of the efficacy of various maxillary molar intrusion therapies: a systematic review

AIMS

To systematically assess the efficacy of the various interventions used to intrude maxillary molars. Furthermore, to evaluate associated root resorption, stability of intrusion, subsequent vertical movement of mandibular molars, cost effectiveness, compliance, patient reported outcomes and adverse events.

METHODS

A pre-registered and comprehensive literature search of published and unpublished trials until March 22nd 2023 with no language restriction applied in PubMed/Medline, Embase, Scopus, DOSS, CENTRAL, CINAHL Plus with Full Text, Web of Science, Global Index Medicus, Dissertation and Theses Global, ClinicalTrials.gov, and Trip (PROSPERO: CRD42022310562). Randomized controlled trials involving a comparative assessment of treatment modalities used to intrude maxillary molars were included. Pre-piloted data extraction forms were used. The Cochrane Risk of Bias tool was used for risk of bias assessment, and The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used for certainty of evidence appraisal.

RESULTS

A total of 3986 records were identified through the electronic data search, of which 24 reports were sought for retrieval. Of these, 7 trials were included. One trial was judged at high risk of bias, while the others had some concerns. Based on individual small sample studies, maxillary molar intrusion was achieved using temporary anchorage devices (TADs) and rapid molar intruder appliance (RMI). It was also observed to a lesser extent with the use of open bite bionator (OBB) and posterior bite blocks. The molar intruder appliance and the posterior bite blocks (spring-loaded or magnetic) also intruded the lower molars. Root resorption was reported in two studies involving TADs. None of the identified studies involved a comparison of conventional and TAD-based treatments for intrusion of molars. No studies reported outcomes concerning stability, cost-effectiveness, compliance and patient-reported outcomes. Insufficient homogeneity between the included trials precluded quantitative synthesis. The level of evidence was very low.

CONCLUSIONS

Maxillary molar intrusion can be attained with different appliances (removable and fixed) and with the use of temporary anchorage devices. Posterior bite blocks (spring-loaded or magnetic) and the RMI offer the additional advantage of intruding the mandibular molars. However, stability of the achieved maxillary molar intrusion long term is unclear. Further high-quality randomized controlled trials are needed.

Effectiveness of Flapless Cortico-Alveolar Perforations Using Mechanical Drills Versus Traditional Corticotomy on the Retraction of Maxillary Canines in Class II Division 1 Malocclusion: A Three-Arm Randomized Controlled Clinical Trial

BACKGROUND AND OBJECTIVES

Both invasive and minimally invasive surgical methods have recently gained popularity in accelerating orthodontic tooth movement. Traditional corticotomy (TC) was one of the first effective invasive surgical techniques in shortening orthodontic treatment time, whereas the flapless cortico-alveolar perforations (FCAPs) technique is a modern minimally invasive method that has recently shown good results in different types of orthodontic tooth movement. Therefore, this study aimed to compare the effectiveness of TC versus FCAPs in maxillary canine retraction when treating Class II division 1 malocclusion patients.

MATERIALS AND METHODS

This was a single-blinded, single-center, three-arm randomized controlled trial. A total of 51 patients (22 males, 29 females, mean age 20.98 ± 1.95) whose treatment planning included the extraction of maxillary first premolars were enrolled and randomly divided into three groups: the TC group, the FCAPs group, and the control group. The assessed outcomes were the amount of canine retraction, anchorage loss, and canines' rotation, which was evaluated at five-time points till the completion of canine retraction.

RESULTS

There were statistically significant differences in the amount of canine retraction between the three groups in the first two months (p < 0.001), with greater mean values in the TC group (p < 0.001) in the first month. However, the amount of canine retraction in the FCAPs group was significantly greater in the second month compared to the TC group (p = 0.003) and the control group (p < 0.001). In the first month of canine retraction, anchorage loss, and canine rotation were significantly lesser in the TC and FCAPs groups than in the control group (p < 0.001). On the contrary, the canines' rotation amount after the completion of retraction was greater in the TC group than in the other two groups (p < 0.001).

CONCLUSION

TC and FCAPs are efficient adjunctive surgical methods for accelerating canine retraction. At the end of the first month, the TC accelerated canine retraction by 59.85% and FCAPs by 44% compared to the conventional retraction. At the end of the second month, the acceleration was less than recorded in the first month (35.44% and 50.20%, respectively). The acceleration effect of the surgical interventions appeared transient and did not last in the following observation period.

Evaluation of Patient-Centered Outcomes Associated With the Acceleration of en-Masse Retraction of Upper Anterior Teeth Assisted by Flapless Corticotomy Compared to Traditional Corticotomy: A Two-Arm Randomized Controlled Trial

OBJECTIVE

This study aimed to assess the levels of pain, discomfort, and functional impairment associated with the en-masse retraction of the upper anterior teeth when treating Class II division 1 malocclusion patients using traditional corticotomy or flapless corticotomy. In addition, an assessment of patients' satisfaction with the selected surgical intervention was undertaken at one-month post-operatively.

MATERIALS AND METHODS

The study sample comprised 40 patients with Class II division 1 malocclusion, randomly assigned to either the traditional corticotomy group (n=20) or the flapless corticotomy group (n=20). Patients underwent extraction of the maxillary first premolars, and orthodontic mini-screws were placed between the maxillary second premolars and the first molars for skeletal anchorage. An en-masse retraction was accomplished in both groups. Patients were asked to fill in a questionnaire at 24 hours (T1), four days (T2), seven days (T3), 14 days (T4), and 28 days (T5) after the surgical intervention using standardized questionnaires. Most questions were answered on a visual analog scale where zero scores meant the absence of pain, discomfort, or functional impairment, and 100 scores meant the worst feelings of these traits.

RESULTS

All patients in both groups entered data analysis with no dropouts. All measured levels were significantly greater in the traditional corticotomy group during the first two weeks following the corticotomy intervention in terms of pain perception (P˂0.001), discomfort (P=0.004), and difficulty in chewing (P=0.015). Additionally, during the first week following corticotomy, levels of perception of discomfort (P˂0.001), difficulty in swallowing (P=0.001), and limitation of jaw movement (P˂0.001) were significantly greater in the traditional corticotomy group. Patient satisfaction, the recommendation to a friend, and acceptance of flapless corticotomy were significantly greater than traditional corticotomy (P=0.002, P=0.001, respectively). 78% of patients in the traditional corticotomy group considered it more discomfort than a tooth extraction, while 50% of patients in the flapless corticotomy group considered tooth extraction more discomfort, with a significant difference between the two groups (P=0.001).

CONCLUSIONS

The levels of negative patients' reported outcomes were significantly smaller with flapless corticotomy than with traditional corticotomy. Traditional corticotomy was associated with mild to moderate levels of pain, swallowing difficulty, moderate levels of discomfort, chewing difficulty, and jaw movement limitation after 24 hours of the surgical procedure. In contrast, flapless corticotomy was less problematic and associated with mild pain, swelling, chewing difficulty, jaw movement limitation, and swallowing difficulty at the same assessment time. Patient satisfaction, acceptance, and recommendation to a friend were greater for flapless corticotomy than traditional intervention.

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.

The effectiveness of minimally-invasive corticotomy-assisted orthodontic treatment of palatally impacted canines compared to the traditional traction method in terms of treatment duration, velocity of traction movement and the associated dentoalveolar changes: A randomized controlled trial

Objective: To evaluate the effectiveness of a minimally-invasive corticotomy-assisted treatment of palatally impacted canines (PICs) compared with the traditional method by evaluating treatment time, the velocity of movement, and the associated dentoalveolar changes. Materials and methods: Forty-six patients with palatally or mid-alveolar upper impacted canines were recruited and distributed into two groups: the corticotomy-assisted traction group (CAT group, mean age: 20.39±2.27 years) and the traditional treatment group (TT group, mean age: 20.26±2.17 years). The closed surgical approach was used in both study groups. The velocity of traction movement, traction duration and overall treatment duration were evaluated clinically. In addition, the bone support ratios and the amount of root resorption were assessed on cone-beam computed tomography (CBCT) images. Results: At the end of treatment, significant differences were found between the two groups regarding the velocity of traction movement, traction time, and overall treatment time (P<0.05). The mean velocity of traction movement in the CAT group was greater than the TT group ( x velocity=1.15±0.35 mm/month; 0.70±0.33 mm/month, P=0.027, respectively). The duration of the active traction and the overall orthodontic treatment in the CAT group were significantly shorter than the TT group by 36% and 29%, respectively. The mean bone support ratios of the aligned canines did not differ significantly between the two groups (88% vs. 89% in the CAT and TT groups, respectively). No significant differences were found between the two groups regarding the mean amount of root resorption on the adjacent laterals ( x resorption = 1.30±1.18 mm; 1.22±1.02 mm, P=0.612, in CAT and TT groups, respectively). Conclusions: The traction movement velocity of the palatally impacted canines can be increased using minimally-invasive corticotomy-assisted orthodontic treatment. The side effects of the acceleration procedure were minimal and almost similar to those of the traditional technique.

A Novel Method to Accelerate Orthodontic Tooth Movement Using Low-Intensity Direct Electrical Current in Patients Requiring en-Masse Retraction of the Upper Anterior Teeth: A Preliminary Clinical Report

BACKGROUND

Shortening the duration of orthodontic treatment by speeding up the rate of tooth movement has become an essential goal for both orthodontists and patients. This preliminary report aimed to investigate the safety and effectiveness of a new intraoral removable electrical device in accelerating the en-masse retraction of the upper anterior teeth using low-intensity direct electrical current.

METHODS

This prospective preliminary interventional clinical study was conducted at the Department of Orthodontics, Faculty of Dentistry, Damascus University, Syria, between March 2019 and February 2020. The sample consisted of six patients (four females and two males; mean age: 19.55 ± 0.89 years) whose initial diagnosis was class II division I malocclusion, and their treatment plan suggested the extraction of upper first premolars followed by en-masse retraction. The electrical stimulation was applied on the maxillary anterior region during the en-masse retraction phase using a specially fabricated removable device that was designed by two coauthors of this manuscript (RIS, MYH). Patients were asked to wear their own electrical devices inside their mouths for five hours daily. The primary outcomes were the en-masse retraction rate and duration. The secondary outcomes were safety and patient acceptance.

RESULTS

The average total retraction rate during the treatment period was 0.97±0.06 mm/month. The total amount of retraction achieved during follow-up was 5.65 ± 0.85 mm, which was about 91.86% of the space resulting from the extraction of the upper first premolars. The mean treatment duration to complete the en-masse retraction was 5.66±0.81 months. No side effects of the electrical stimulation were found during the follow-up.

CONCLUSIONS

Low-intensity direct electrical current could be an effective method to accelerate orthodontic movement. The electrical accelerating device used in this study effectively increased the en-masse retraction rate of the upper anterior teeth without any side effects and with high patient acceptance.

Effects of Flapless Laser Corticotomy in Upper and Lower Canine Retraction: A Split-mouth, Randomized Controlled Trial

Aim One of the major difficulties in orthodontic treatment is the lengthy course of therapy, particularly in situations involving extractions. Hence, various methods for accelerating tooth movement rate had been devised. Flapless corticotomy is one of those methods. This study aimed to evaluate the effects of flapless laser corticotomy (FLC) compared to the conventional retraction (CR) method on the rate of canine retraction. Methods A split-mouth, randomized controlled trial included 56 canines from 14 patients (12 females and two males) with a mean age of 20.4 ± 2.5 years, who were complaining of bimaxillary protrusion requiring extraction of four premolars. All canines were randomly assigned to four groups (maxillary FLC, maxillary control CR, mandibular FLC, and mandibular control CR). Randomization was performed by creating two equal, random computer-generated lists with a 1:1 allocation ratio-one list for the right side and one for the left. The allocation concealment was achieved using opaque sealed envelopes until the time of intervention. FLC was applied on the experimental sides before canine retraction by drilling six holes penetrating 3 mm into the bone on the mesial and distal sides of the canines. Subsequently, all canines were retracted employing closed coil springs to deliver a force of 150 g using indirect anchorage from temporary anchorage devices (TADs). All canines were assessed at T0 (before retraction), T1 (one month after retraction), T2 (two months), and T3 (three months) using three-dimensional (3D) digital models. Additionally, canine rotation, molar anchorage loss assessed using 3D digital models, root resorption assessed using cone beam computed tomography (CBCT), probing depth, plaque, gingival indices, and pulp vitality were all evaluated as secondary outcomes. It was possible to blind only the outcome analysis expert (single-blinded). Results The measurements of canine retraction during the follow-up period from T0 to T3 were 2.46 ± 0.80 mm and 2.55 ± 0.79 mm in maxillary FLC and control groups, respectively, and 2.44 ± 0.96 mm and 2.31 ± 0.95 mm in mandibular FLC and control groups, respectively. The results demonstrated a statistically non-significant difference in the distance of canine retraction between the FLC and control groups at all time points. Moreover, no differences were observed between groups in canine rotation, molar anchorage loss, root resorption, probing depth, plaque, gingival indices, and pulp vitality (p > 0.05). Conclusion In the FLC procedure performed in this study, the rate of upper and lower canine retraction could not be accelerated and no significant differences were observed between FLC and control groups in canine rotation, molar anchorage loss, root resorption, periodontal condition, and pulp vitality.

Investigating the Effectiveness of Low-Level Laser in Reducing Root Resorption of the Upper Incisors During Intrusion Movement Using Mini-Implants in Adult Patients With Deep Overbite: A Randomized Controlled Clinical Trial

BACKGROUND

Deep bite is a common characteristic of malocclusion, and many methods are used to treat it, including mini-implants used for the intrusion of the upper incisors. Orthodontically induced inflammatory root resorption (OIIRR) is an inevitable and unexpected side effect of orthodontic therapy. However, resorption of the root could be affected by the type of tooth movement, such as intrusion. Several studies have indicated the effectiveness of low-level laser therapy (LLLT) in accelerating orthodontic movement, but studies that have evaluated the role of this laser in reducing the risk of OIIRR have been limited. This trial aimed to investigate the effectiveness of LLLT in reducing the resorption of the roots of the upper incisors during their intrusion in the context of deep bite correction.

MATERIALS AND METHODS

Thirty patients (13 males, 17 females; mean age 22.4±3.37 years) with deep overbite were recruited and allocated to the laser or the control groups. Mini-implants were inserted between the roots of the upper central incisors and the lateral incisors from the labial aspect at the gingival-mucosal junction on both sides with a force of 40 g on each side through an NiTi coil spring. A low-level laser (Ga-Al-As) with 808 nm wavelength in a continuous mode, with the parameters 250 milliwatt power output, 4 Joules/point energy density, and 16 seconds irradiation per point, was applied to the root of each of the upper incisors. The laser was applied on the first day of the upper incisor intrusion (T1), then on days 3, 7, and 14 of the first month. In the second month, the laser was applied every 15 days, adjusting the spring strength every four weeks until the end of the intrusion stage (T2), which was determined by reaching a normal overbite. As for patients in the control group, the strength of the nickel-titanium springs was adjusted every four weeks to the required strength of 40 g on each end until reaching a normal overbite.

RESULTS

There was a volumetric decrease in both groups' upper central and lateral incisors roots, and this decrease was statistically significant (P<0.001). However, the difference between the two groups was not statistically significant in each central and lateral incisor volume root (P=0.345 and 0.263 for U1 and U2, respectively). Also, both groups had a linear decrease in upper central and lateral incisors roots, which was statistically significant (P<0.001). At the same time, the difference between the two groups was not statistically significant in each central and lateral incisor root length (P=0.343 and 0.461 for U1 and U2, respectively).

CONCLUSION

The low-level laser irradiation using the current protocol did not significantly affect the amount of root resorption induced by incisor intrusion in the experimental group compared to the control group.

Accelerated Canine Retraction by Using Mini Implant With Low-Intensity Laser Therapy

Background The continuous increase in demand for reduced treatment times has led researchers to think in terms of "accelerated orthodontics." Generally, the duration for fixed orthodontic treatment is around two to three years. Prolonged use of braces leads to external root resorption, a high risk of caries, and decreased patient compliance. Therefore, finding an optimal supplementary approach to achieve faster tooth movement is still considered a subject of interest. Low-intensity laser therapy (LILT) is one of the non-invasive surgical techniques in the field of accelerated orthodontics. Low-level laser therapy (LLLT) has demonstrated faster healing, less bleeding, and biostimulation and anti-inflammatory effects. According to all studies, it accelerates tooth movement, thereby reducing braces treatment time. It is simple, safe, and minimally invasive. Despite these pieces of evidence, studies have shown variable findings in low-level laser therapy. This study evaluates the effect of LLLT on accelerated orthodontics in comparison with conventional canine retraction. An aluminum gallium arsenide-type diode laser with a wavelength of 940 nm has been used in this study. Methodology This study was conducted using the split-mouth method, which included 20 patients with permanent dentition who required first premolar extractions. A miniscrew implant was placed on both the right and left sides for maximum anchorage. Irradiation doses were applied on days 0, 3, 7, and 14 of the first month. Subsequently, irradiations were given every 15 days until the canine's retraction was complete in the test group. Results The study results three months after the canine retraction in the test and control groups (M1) were 0.81 ± 0.03 mm/month and 0.74 ± 0.04 mm/month, respectively, indicating a significantly higher rate of canine retraction in the test group than in the control group (P < 0.0001). The average increase in the amount of tooth movement at three months was 40.1% and 36.3% in the test and control groups, respectively. However, the average increase in the amount of movement of teeth following canine retraction was 100% in the test group and 68.2% in the control group. There were significant variations in the pain score between Day 1 and Day 3 (P = 0.003) in the test group; however, there was no analytic variation in the pain score between Day 1 and Day 30 in the test group (P = 0.18). The pain score between Day 3 and Day 30 was significantly lower. Conclusions It was concluded that the rate of canine retraction increases when it is combined with LILT-assisted accelerated orthodontics in comparison to conventional canine retraction. Although LLLT does not provide immediate pain relief, it relieves the sensation of pain after 24-72 hours. LILT is an innovative, non-invasive technique that allows rapid orthodontic tooth movement. The rate of canine retraction increases when it is combined with LILT-assisted accelerated orthodontics in comparison to conventional canine retraction using mini-implants.

The Efficacy of Accelerating Orthodontic Tooth Movement by Combining Self-Ligating Brackets With One or More Acceleration Methods: A Systematic Review

This review aimed to evaluate the effectiveness of using one or more acceleration methods with self-ligating brackets to accelerate orthodontic tooth movement in adults and the associated effects of these interventions. An electronic search of the following databases (PubMed, Scopus, Google Scholar, EMBASE) was performed (From January 1990 to November 2021). ClinicalTrials.gov and the International Clinical Trials Registry Platform were also electronically searched to find any unpublished studies and ongoing trials. The selected randomized controlled trials (RCTs) involved adult patients treated using self-ligating brackets combined with one or more acceleration methods compared with self-ligating brackets or conditional brackets alone. The risk of bias was assessed using Cochrane's risk of bias tool. A total of seven RCTs and one controlled clinical trial (CCT) were included in this review. Combining self-ligating brackets with flapless corticotomy, low-level laser therapy (LLLT), and infrared light accelerated orthodontic movement by 43% and 50% for surgical methods, 20-50% for LLLT, and 22% for infrared light. Regarding side effects on periodontal tissues, neither flapless corticotomy nor low-frequency vibrational forces caused any damage. Combining self-ligating brackets and flapless corticotomy, low-level laser, or infrared light effectively accelerated orthodontic movement by 20% to 50 %. In contrast, the combination of self-ligating brackets with vibrational forces did not affect speeding tooth movement. The acceleration methods did not have any side effects on the periodontal tissues, but the available evidence was insufficient. There is a need for further primary research regarding the effectiveness of combining self-ligating brackets with acceleration methods and the possible untoward side effects.

Evaluation of Soft and Hard Tissue Changes Following the Use of Rapid Molar Intruder for the Management of Skeletal Anterior Open Bite in Mixed Dentition: A Randomized Controlled Trial

Objective The aim of the study was to evaluate skeletal, dentoalveolar, and soft tissue changes following early anterior open bite (AOB) treatment using a rapid molar intruder (RMI). Materials and methods A two-arm, parallel-group, randomized controlled trial was conducted on 40 patients aged 8-12 years with anterior open bites. They were randomly allocated to the RMI group and the untreated control group (UCG) with a 1:1 allocation ratio. At the beginning of the treatment (T1) and after nine months of treatment (T2), lateral cephalometric images were taken of each patient. The primary outcome measures were skeletal, dentoalveolar, and soft tissue changes. A two-sample t-test was used in the intergroup comparisons of the cephalometric measurement. Results The findings showed that the overbite increased significantly in the RMI group compared to the control group (x = 4.44 mm, x = 0.19 mm, respectively; p<0.001). A statistically significant intrusion of the upper and lower first molars was observed in the RMI group (x = 2.9 mm, x = 1.54 mm, respectively) compared to a slight extrusion in the control group. The differences between the two groups were significant (p<0.001). The SN: GoMe angle and the sum of Bjork decreased significantly in the RMI group compared to an increase observed in the control group. The differences between the two groups were significant (p<0.001). Conclusion The rapid molar intruder is an effective appliance for correcting anterior open bites in mixed dentition, inducing favorable skeletal, dentoalveolar, and soft tissue changes.

Three-dimensional dentoalveolar changes in open bite treatment in mixed dentition, spurs/posterior build-ups versus spurs alone: 1-year follow-up randomized clinical trial

This randomized clinical trial aimed to compare the three-dimensional dentoalveolar maxillary changes after anterior open bite treatment with bonded spurs and build-ups versus bonded spurs alone. Patients from 7 to 11 years of age with anterior open bite were randomly allocated into two groups. Bonded spurs and posterior build-ups were used in the experimental group and only bonded spurs were used in the comparison group. The randomization sequence was generated at www.randomization.com. Opaque, sealed and sequentially numbered envelopes were part of the allocation concealment. Digital dental models were acquired before (T1) and after 12 months of treatment (T2) and de-identified for analysis purposes. Three-dimensional changes of maxillary permanent incisors and first molars were evaluated by means of T1 and T2 dental model superimposition. Landmark-based registration on the posterior teeth and registration on the palate using regions of interest were performed. T or Mann–Whitney U tests were used for intergroup comparisons (P < 0.05). Mean difference (MD) and 95% confidence interval (CI) were calculated. Twenty-four children (17 girls and 7 boys) were included in the experimental group (mean age 8.22 ± 1.06 years) and 25 children (14 girls and 11 boys) were included in the comparison group (mean age 8.30 ± 0.99 years). After 12 months of treatment, inferior displacements of maxillary incisors were similar in the experimental (1.55–2.92 mm) and comparison (1.40–2.65 mm) groups. Inferior displacement of the maxillary molars was also similar in both groups (MD: − 0.13 mm; 95% CI − 0.38, 0.12). The experimental and comparison groups showed medial and lateral displacements of the permanent first molars, respectively (MD, − 0.31 mm; 95% CI − 0.51, − 0.11). Lingual inclination of the permanent first molars were observed in the experimental group and buccal inclination in the comparison group (MD, − 2.16°; 95% CI − 3.72, − 0.60). Similar three-dimensional displacements of maxillary central and lateral incisors, and inferior displacements of maxillary permanent first molars were observed in both groups. Bonded spurs associated with posterior build-ups demonstrated some medial displacement and lingual inclination of the maxillary permanent first molars while opposite changes were noticed in the comparison group.

Trial registration: Clinicaltrials.gov; NCT03702881, date of registration: October 11, 2018.

Evaluation of patient-reported outcome measures (PROMs) during surgically-assisted acceleration of orthodontic treatment: a systematic review and meta-analysis

BACKGROUND

With the widespread of surgically-assisted orthodontic acceleration, the analysis of patient-reported outcome measures (PROMs) has become very important to assure patient acceptance and satisfaction before adopting any acceleration procedure.

OBJECTIVE

This review aimed to critically appraise the available evidence regarding the levels of pain, discomfort, functional impairments, and other patient-reported outcome measures during surgically-assisted acceleration of orthodontic treatment compared with the traditional non-accelerated treatment.

SEARCH METHODS

Eight electronic bibliographic databases were searched from January 1990 till May 2022. A manual search of the selected orthodontic journals was also undertaken.

SELECTION CRITERIA

Randomized controlled trials (RCTs) were included in this systematic review on patients undergoing orthodontic treatment with one group subjected to an acceleration procedure.

DATA COLLECTION AND ANALYSIS

Cochrane's risk of bias tool (RoB2 tool) was used to assess the risk of bias of the included RCTs. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidelines were used to assess the overall quality of the evidence.

RESULTS

Thirteen RCTs were included in this review (333 patients), and only minimally invasive surgically-assisted acceleration studies were included. Two RCTs were included in the quantitative synthesis of data. After the first day of surgical intervention, the levels of pain and discomfort ranged from mild to moderate in the surgical groups (mean values ranged from 0.8 to 6.8), while it was mild in the control groups. However, on the seventh day after the surgical intervention, the levels of pain, discomfort, swelling, and functional impairments were almost similar between groups. According to the GRADE, the quality of evidence supporting these findings ranged from low to very low.

CONCLUSIONS

All surgical interventions were minimally invasive. There was very low to low evidence that acceleration caused mild to moderate pain and discomfort on the first day after the surgical intervention and disappeared completely at one week following surgery. Functional impairments were found within acceptable limits immediately and in the short-term follow-up. More high-quality randomized controlled clinical trials are needed to establish good evidence in this field.

REGISTRATION

The protocol of this systematic review was registered in PROSPERO database (CRD42021274481) during the first stages of this review.

Three-Dimensional Assessment of the Temporomandibular Joint Changes Following Reversed Twin Block Therapy of Patients With Skeletal Class III Malocclusion in Conjunction With the Photobiomodulation Therapy: A Randomized Controlled Clinical Trial

Background: Despite the positive effect of the photobiomodulation therapy (PBMT) application on animals, the primary role of this technique on the human condyle is still unclear. Several experimental reports have shown the efficacy of PBMT in inducing cellular changes in the temporomandibular joint (TMJ) region during functional treatment of patients with skeletal deformities. Still, the lack of information about its effects on human condyles requires further studies.

Objectives: This study aimed to evaluate the effect of PBMT on the TMJ components following Class III treatment with the reversed twin block (RTB) appliance in growing patients. 

Materials and Method: Forty children (12 females, 28 males) between the age of nine and eleven years with skeletal Class III were assigned randomly to the RTB group with photobiomodulation (RTB+PBMT) or the control group (RTB). The PBMT was applied to the TMJ region using an 808-nm wavelength Ga-Al-As semiconductor laser device with 5 Joules/cm² energydensity on days 1, 3, 7, and 14 of the first month. Afterwards, the irradiation was conducted every 15 days until the end of the treatment. Cone-beam computerized tomography (CBCT) images were taken before (T1) treatment and following the end of treatment (T2) to assess TMJ and skeletal changes.

Results: Condylar volume was significantly increased in the RTB group only by a mean of 287.97 mm³ (p<0.001). The significantly backward and upward condylar movement was observed in the RTB and RTB+PBMT groups (superior joint space (SJS): 0.26 mm, 0.15 mm; posterior joint space (PJS): 0.42mm, 0.11mm, respectively). The RTB group showed the most remarkable changes. Significant improvement of the sagittal maxilla-mandibular relationship was greater in the RTB+PBMT group compared to the RTB group (p=0.02).

Conclusion: There were no considerable differences in the condylar position after Class III treatment between the RTB and the RTB+PBMT groups. But a difference in the condylar volume was noticed between the two group.

Evaluation of the Effectiveness of Surgical Interventions Versus Non-surgical Ones When Used in Conjunction With Fixed Appliances to Accelerate Orthodontic Tooth Movement: A Systematic Review

The objectives of this review were to evaluate the currently available evidence regarding the effectiveness of surgical versus non-surgical acceleration methods and the side effects associated with these methods. Nine databases were searched: the Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE®, Scopus®, PubMed®, Web of Science™, Google™ Scholar, Trip, OpenGrey, and PQDT OPEN from pro-Quest®. ClinicalTrials.gov and the International Clinical Trials Registry Platform Search Portal (ICTRP) were screened to explore ongoing studies and unpublished literature. Randomized controlled trials (RCTs), as well as controlled clinical trials (CCTs) of patients who received surgical interventions (invasive or minimally invasive techniques) in conjunction with traditional fixed appliances and who were compared to the non-surgical interventions, were included. The Cochrane tool for risk of bias (RoB.2) was used for evaluating RCTs, whereas the ROBINS-I tool was used for the CCTs. This systematic review included four RCTs and two CCTs (154 patients). The surgical and non-surgical interventions were found to have the same effect on orthodontic tooth movement (OTM) accelerating in four trials. In contrast, the surgical interventions were superior in the other two studies. High heterogeneity among the included studies prevented conducting the quantitative synthesis of the findings. The reported side effects related to the surgical and non-surgical interventions were similar. A "very low" to "low" evidence indicates that the effectiveness of surgical and non-surgical interventions in the acceleration of orthodontic tooth movement is similar, with no differences in the associated side effects. More high-quality clinical trials to compare the acceleration effectiveness between both modalities in different types of malocclusion is required.

The Effectiveness of Conventional and Accelerated Methods of Orthodontic Traction and Alignment of Palatally Impacted Canines in Terms of Treatment Time, Velocity of Tooth Movement, Periodontal, and Patient-Reported Outcomes: A Systematic Review

The objective of the current review was to evaluate the effectiveness of traditional and accelerated methods of palatally impacted canine's (PIC) traction in terms of treatment duration, velocity, periodontal, and patient-reported variables.

An electronic search for randomized controlled trials (RCTs) and controlled clinical trials (CCTs) published between January 1990 and October 2021 was conducted in nine databases. Five major orthodontic journals were hand searched for additional studies. The participants were patients with unilateral or bilateral PICs who received conventional or accelerated orthodontic treatment with fixed appliances. Cochrane’s risk of bias tool (RoB 2 tool) for RCTs and ROBINS-I tool for CCTs were used to assess the risk of bias. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidelines were used to assess the overall quality of the evidence.

Nine articles (eight RCTs and one CCT) were included in this review (371 patients). There was no clarity in most studies about the possible effect of the mechanical traction method on treatment outcomes. The treatment duration decreased (about three to six months) when the open surgical method was used with traditional techniques and the traction velocity increased significantly (about 1-1.5 mm/month) when acceleration methods were used. No significant differences were found between the conventional intervention groups, as well as between the traditional and accelerated groups, in terms of most periodontal variables (p > 0.005).

No significant differences were found in the pain levels associated with traditional PICs' traction when comparing different exposure methods in the short-term follow-up (1-10 days), while contradictory results were found in the pain incidence between these methods. The relationship between the pain/discomfort levels and the type of mechanical traction method was not evaluated. According to the GRADE, the quality of evidence supporting these findings ranged from low to very low.

The combination of the open surgical technique with various designs of either superelastic wires or elastic traction means can lead to a reduction in the orthodontic treatment duration of PICs. The use of direct anchorage by miniscrews to move the PICs away from the adjacent teeth roots can lead to a reduction in root resorption and shorten the treatment duration. The evidence supporting these findings ranged from low to very low. The use of different types of mechanical means for conventional PICs' traction, with the use of open or closed traction techniques, does not lead to significant differences in periodontal outcomes between intervention groups. Contradictory results exist regarding the severity of the perceived pain in relation to the surgical exposure type, and the relationship between this variable and the mechanical traction method is still unclear. The use of accelerated methods for PICs' traction can lead to an increase in the velocity of traction movement with no significant differences in periodontal outcomes between accelerated and conventional methods. The evidence supporting these findings ranged from low to very low. More high-quality randomized CCTs are needed to establish good evidence in this field.

The protocol of this systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42021274476) during the first stages of this review.