Red Light Therapy for Orthodontic Tooth Movement: Scientific Evidence

Movement of 1.1 mm at 4 weeks with photobiomodulation (PBM) against 0.6 mm with a placebo light was the main result of a 2025 randomized controlled trial at an orthodontic institute in Slovenia. 32 patients with mild crowding, 10 males and 22 females, aged 14.6 on average, were analyzed after 35 had been randomized: 14 in the PBM group and 18 in the placebo group. Within 2 days of fixed braces going on, the PBM group had an LED device emitting 625, 660, and 850 nm light at 16 mW/cm² and 0.96 J/cm² for 10 minutes twice a week for 4 weeks, while the placebo group had non-therapeutic visible light. Tooth movement on 3D models was significantly greater with PBM at both 1 week and 4 weeks, and gum overgrowth was less frequent. Plaque, gum bleeding, and self-rated pain did not differ, so the light appeared to speed early orthodontic tooth movement without easing discomfort.

This 2025 randomized controlled trial at a dental college in Saudi Arabia asked what low-level laser therapy (LLLT) does to the density of the lower jaw's outer bone during orthodontic treatment, rather than measuring tooth movement itself. 40 patients aged 18 to 30 with fixed braces were split equally into 2 groups, and the LLLT group had an 808 nm diode laser at 100 mW and 8 J/cm² applied to the lower jaw bone on alternate days for the first month. Cone-beam CT scans were taken at the start and at 12 weeks, and bone density at the first molar and canine regions was read from the grayscale values. At 12 weeks, the LLLT group showed a significant reduction in cortical bone density from the starting scans, 935.2 to 879.5 Hounsfield units at the first molar, the researchers reported. They concluded that LLLT lowers the density of the outer jaw bone during treatment, which may make faster orthodontic tooth movement possible.

Orthodontists at the University of Damascus in Syria asked how patients themselves experience 2 ways of speeding orthodontic tooth movement during canine retraction, low-level laser therapy (LLLT) and piezocision, in a 3-arm randomized controlled trial published in 2024. The study included 54 patients (12 male, 42 female), all about 21 years old, who had an upper first premolar removed on each side and were split evenly among a piezocision group, an LLLT group receiving 810 nm light at 500 mW, and a control group. According to the abstract, pain and discomfort were lower in the laser group than in both other groups for the first 2 weeks. The piezocision group reported more pain and discomfort than the controls in the first week, more swelling than both other groups, and more chewing difficulty than the laser group. Both intervention groups reported higher satisfaction with the speed of canine movement than the controls, and both groups reported high acceptance of the treatment.

When low-level laser therapy (LLLT) was added to fixed braces, treatment finished in 8.4 months on average, compared with 12 months without it, in a 2024 randomized controlled trial at a dental college in India. 60 patients aged 12 to 30 who needed fixed appliance therapy were randomly assigned to a biomodulation group, which had 810 nm light at 800 mW for 60 seconds on the gum around the appliances, or to a control group. Treatment ran for 252 days in the laser group. The trial found a significant reduction in treatment duration with LLLT, saving 30% of total treatment time. Biomodulation with LLLT was judged a promising adjunct to orthodontic treatment that significantly speeds tooth movement.

A 2024 randomized controlled trial at a dental college in Saudi Arabia tested photobiomodulation (PBM) as a way to shorten orthodontic treatment, which conventionally takes considerable time to align and correct the teeth. 60 patients were divided equally into a PBM group, which had 810 nm light applied for 60 seconds directly to the treated area at each visit, and a control group, with both groups having their braces adjusted as usual. Treatment duration, changes in tooth alignment, and patient discomfort were compared. The PBM group appeared to finish treatment in a significantly shorter time than the control group, with alignment improving in both groups. Patients in the PBM group reported minimal discomfort, and the authors concluded that PBM can speed orthodontic tooth movement and was well tolerated.

In a 2024 6-arm split-mouth randomized controlled trial at a university in Iran, researchers randomized 64 quadrants of the mouth in 32 patients to low-level laser therapy (LLLT), piezocision, or the 2 combined, each against an untreated control side, to compare 3 ways of speeding orthodontic tooth movement. The first premolars were removed on both sides, and canine retraction began, with the laser side receiving 940 nm light at 0.5 W and 8 J for 16 seconds at 12 sites, over 63 days. Piezocision, small surgical cuts in the gum and bone beside the tooth, was applied alone or with the laser. Retraction and anchorage loss were measured at 3, 6, and 9 weeks, and after 9 weeks, LLLT had added 0.51 mm of canine retraction, piezocision 1.14 mm, and the combination 1.93 mm over the control sides. All 3 sped retraction significantly, at 1.6-, 1.4-, and 1.2-fold for LLLT in weeks 3, 6, and 9, with the combination strongest and LLLT alone weakest.

This 2023 randomized controlled trial in São Paulo, Brazil, tested whether photobiomodulation (PBM) speeds the orthodontic uprighting of tipped lower molars, the movement that brings a tilted molar back to vertical before the gap beside it is restored. 34 people needing a lower molar uprighted were randomly split between uprighting plus PBM from an 808 nm diode laser at 100 mW, 1 J per point at 10 points and 25 J/cm², and uprighting plus a simulated PBM, over 3 months. According to the abstract, the PBM group showed more uprighting movement than the control group after 3 months, together with a change in interleukin-1β, an inflammatory signal of bone remodeling that lets a tooth move. Pain, the amount of pain medication used, and scores on an oral health questionnaire did not differ between the groups, so the laser appeared to speed orthodontic tooth movement during molar uprighting without changing how the treatment felt.

Across 19 split-mouth randomized clinical trials found in 4 databases up to October 2022, a 2023 systematic review and meta-analysis from the University of Barcelona in Spain asked whether low-level laser therapy (LLLT) accelerates orthodontic tooth movement and which wavelength does it best. The review included only trials in systemically healthy patients that measured canine retraction, pooling 18 in a random-effects model. According to the abstract, the pooled results point to a tendency toward faster orthodontic canine retraction in the laser groups at the 1-, 2-, and 3-month follow-ups. Wavelengths of 810 nm or below and energy densities of 5.3 J/cm² or below were associated with faster orthodontic tooth movement.

A 6-arm randomized controlled trial of 90 rotated teeth (15 per group) was designed in 2023 by periodontologists at Mazandaran University of Medical Sciences in Iran to compare ways to limit relapse after orthodontic tooth movement. The teeth, all having completed fixed orthodontic treatment, received no intervention, photobiomodulation alone from a 940 nm laser at 0.2 W and 4 J/cm², scalpel fiberotomy, fiberotomy cut with the same laser at 1.5 W, or either fiberotomy followed by photobiomodulation. Relapse measured on photographs and dental casts differed significantly among the groups, highest in the controls, then photobiomodulation alone, laser fiberotomy, conventional fiberotomy, conventional fiberotomy plus photobiomodulation, and lowest with laser fiberotomy plus photobiomodulation. The conclusion drawn was that photobiomodulation combined with either form of fiberotomy can be effective in reducing relapse, with no group differing in gum recession, pocket depth, or pain, and further trials needed to confirm it.

A split-mouth design, 1 side of each patient's mouth treated and the other as control, underpinned a 2023 randomized controlled trial at a dental institute in India of low-level laser therapy (LLLT) for orthodontic tooth movement, cytokine levels, and pain. 40 patients with an average age of 19.7, a normal molar bite, and protruding front teeth had the upper first premolars removed, and both eye teeth pulled back on coil springs. The control canine moved on the spring alone, while the test side had a 980 nm gallium aluminum arsenide diode laser at 100 mW and 8 J/cm² in contact with the gum for 10 seconds per point over 84 days. Researchers found a highly significant difference in the extent of canine distalization between the test and control sides, and interleukin-1 beta and interleukin-6 surged at 7 days on the laser side, with tumor necrosis factor differing significantly at every stage. Self-rated pain scores differed significantly between the sides at repeated checks, and the authors concluded that the cytokines released under orthodontic force appear to speed tooth movement with less pain.

20 patients who needed their first premolars removed took part in a 2023 split-mouth randomized controlled trial in India of low-intensity laser therapy (LILT) for canine retraction, a 1-stage orthodontic tooth movement. With a miniscrew implant on each side for anchorage, 1 side received a 940 nm diode laser at 100 mW for 10 to 30 seconds on days 0, 3, 7, and 14 of the first month, then every 15 days until retraction was complete. After 3 months, canine retraction averaged 0.81 mm per month on the laser side versus 0.74 mm on the control side, a significantly higher rate. Pain scores fell significantly on the laser side between day 1 and day 3 but not between day 1 and day 30. The authors concluded that LILT speeds canine retraction and, without giving immediate pain relief, eases pain after 24 to 72 hours.

33% faster orthodontic tooth movement was the potential the authors saw in light-emitting photobiomodulation therapy (LPT) after a 2023 randomized controlled trial at a university in Turkey. The trial covered 60 extraction spaces left by removing the upper first premolars in 30 patients: 15 received LPT, and 15 were controls, with segmented springs used for canine distalization, the pulling back of the eye tooth into the gap. The LPT group wore an intraoral LED device emitting 850 nm light at 63 mW/cm² in contact with the teeth for 5 minutes per session over 84 days. Canine retraction averaged 1.36 mm per 21 days with LPT, compared with 1.02 mm in the controls, a statistically greater rate. Anchorage loss, canine rotation, and the tilt of canines and molars did not differ between the groups at any time point, so the extra speed appeared to come without side effects on the surrounding teeth.

2022 brought a scoping review from Mahidol University in Bangkok, Thailand, that set out to build a working protocol for low-level laser therapy (LLLT) in orthodontic practice from the human studies published between 2010 and 2021. 60 clinical studies were included from PubMed, Scopus, Web of Science, Embase, Google Scholar, and reference lists: 25 on speeding orthodontic tooth movement, 40 on pain relief, and 5 on root resorption. Faster tooth movement with the laser was reported in 21 of the 25 studies, with gallium-aluminum-arsenide diodes at 658 to 980 nm, most often 810 nm, applied on the day of force application and then on days 3, 7, and 14 in the usual protocol. Pain relief was reported in 32 of the 40 pain studies, while the 5 root resorption studies were too few and too mixed for any clear verdict. The review's authors appeared satisfied that LLLT supports orthodontic practice for tooth movement acceleration and pain reduction, but noted heterogeneity in laser and treatment parameters, so further research is needed to determine specific settings.

Across 9 clinical trials found in 6 databases before 5 April 2021, a 2022 systematic review and meta-analysis from Brazil examined what photobiomodulation (PBM) does to the chemical signals in gingival crevicular fluid, the fluid in the gum crevice, during orthodontic tooth movement. Low-level laser therapy (LLLT) was the light used in 8 of the 9 trials, at wavelengths from 618 to 980 nm and with differing emission patterns, and risk of bias was rated with 2 standard tools. The analysis found that LLLT raised the levels of 4 inflammation signals, interleukin 1-beta among them, but not 2 others, with conflicting results for 3 more. The pooled increase in interleukin 1-beta was statistically significant, with low certainty of evidence. LLLT may increase these signals, which are thought to take part in the bone remodeling that moves teeth, but the reviewers cautioned that the results should be read with care.

12 patients scheduled to have both upper first premolars removed took part in a 2021 split-mouth randomized controlled trial at Capital Medical University in Beijing, China, on low-level laser therapy (LLLT) and the chemical signals of bone turnover. 1 side of each mouth, chosen at random, was irradiated with an 810 nm diode laser at 100 mW and 6.29 J/cm² for 40 seconds over 28 days, while the other side served as a control. Tooth movement was measured over the 28 days, and gingival crevicular fluid, the fluid in the crevice between the gum and tooth, was sampled for interleukin-1β, RANKL, and osteoprotegerin (OPG), 3 proteins that regulate bone breakdown and rebuilding. Cumulative tooth movement over the 28 days was significantly higher on the laser side than on the control side. OPG fell, and interleukin-1β and RANKL rose on the treated sides, which seemed to show that LLLT at these settings changes bone metabolism in a way that could accelerate orthodontic tooth movement.

A single dose of 940 nm laser light, repeated at 3-week intervals, was the regimen tested against a placebo in a 2021 split-mouth clinical trial at a dental institute in Karachi, Pakistan. 20 patients with class II division 1 malocclusion, 10 male and 10 female, and about 20 years old, had both upper first premolars removed and conventional brackets fitted. Once aligned, the canines were pulled back with nickel-titanium coil springs at 150 g of force, with 1 side irradiated at 100 mW and 7.5 J/cm² for 3 seconds at a point and the other given a sham application. The regimen reportedly accelerated canine retraction by 1.55 mm on the laser side, with a significant reduction in pain compared with the placebo side. This low-level laser schedule can therefore accelerate orthodontic tooth movement and reduce the pain that goes with it, the trial concluded.

2021 brought a retrospective observational study of 84 patients' records that asked whether daily photobiomodulation (PBM) or low-intensity pulsed ultrasound (LIPUS) shortens orthodontic treatment with clear aligners, the removable transparent trays that move teeth in stages. 28 patients used LIPUS for 20 minutes a day, 28 used a PBM device emitting 850 nm light at 60 mW/cm² for 10 minutes a day, and 28 used aligners alone, with total treatment time compared across the 3 groups. Treatment took 719 days on average with aligners alone, 533 days with LIPUS, and 528 days with PBM. The authors concluded that daily PBM cut treatment time by 26.6% and LIPUS by 26%, both significant reductions against the control group, with no difference between the 2 devices. Daily use of either device during aligner treatment could therefore shorten orthodontic tooth movement.

A 2019 clinical trial at the São Leopoldo Mandic dental research center in Campinas, Brazil, tested photobiomodulation (PBM) on the intrusion of over-erupted upper molars, the pushing of a molar back into the jaw before a missing opposing tooth is replaced. 30 patients took part: 10 controls whose premolars had neither force nor laser, 10 who had molar intrusion on miniscrew anchorage with a 150 g elastic chain, and 10 who had the same intrusion plus PBM. The laser, an 808 nm diode at 100 mW, giving 1 J and 25 J/cm² at a point at 10 points around the tooth, was applied at force application, 3 and 7 days later, and at each monthly activation over 90 days. Intrusion was found to be 0.26 mm per month with the laser, compared with 0.17 mm without, 34% faster, so the planned movement was complete in 8 months instead of 12. Root shortening on 2 of the 3 molar roots was greater in the group without laser, and interleukin-6 and interleukin-8 in the gum crevice fluid stayed higher in the irradiated group throughout, consistent with the bone remodeling that orthodontic tooth movement depends on.

Applying an 810 nm diode laser to 1 side of the mouth every 3 weeks, a 2018 split-mouth clinical trial in Karnataka, India, asked whether low-level laser therapy speeds orthodontic tooth movement during en masse retraction, the drawing back of the front teeth together. 12 patients had the upper canine and front teeth retracted into the extraction space with a constant 150 g force. The treated side received 10 irradiations of 10 seconds each, 5 on the cheek side and 5 on the palate side of the tooth, for a total of 10 J at each appointment over 84 days. Space closure was tracked with a digital caliper between the contact points of the canine and second premolar. The rate of orthodontic tooth movement was faster on the laser side, and the difference between the 2 sides was statistically significant, so an 810 nm diode laser can increase the rate of extraction space closure, the authors concluded.

In 2018, a randomized controlled trial, double-blind and split-mouth, at a dental institute in Punjab, India tested whether low-level laser therapy (LLLT) shortens orthodontic tooth movement and eases the pain that goes with it. 20 patients, 8 male and 12 female, needed both upper canines retracted after premolar removal, so 1 side of each mouth received an 810 nm laser at 200 mW for 80 seconds, while the other served as a control. The laser was pulsed at 2 Hz and delivered 5 J/cm² per session over 21 days. The time taken to complete canine retraction was compared between the 2 sides, and pain was rated on a facial pain scale, with neither age nor sex appearing to affect either measure. The authors concluded that LLLT can reduce the time fixed orthodontic tooth movement takes and the pain patients feel.

6 of 275 studies retrieved from 5 databases were randomized controlled trials fit for pooling in a 2018 meta-analysis from a university in Iran on low-level laser therapy (LLLT) for orthodontic tooth movement of the human canine. Only trials measuring the distance or speed of canine movement over the treatment period were included, and mean differences were pooled with a random effects model. The included trials used lasers from 630 to 940 nm at 5 to 763 mW for 8 seconds to 5 minutes. Canine movement appeared statistically greater with LLLT than in control groups at every check: 0.74 mm at 21 days, 0.40 mm at 1 month, 0.72 mm at 1.5 months, 0.84 mm at 2 months, 0.92 mm at 3 months, and 1.53 mm at 4.5 months. LLLT can speed the movement of the canine and so shorten treatment, and represents a proper adjunct to fixed orthodontic treatment, the reviewers concluded.

Micro-osteoperforations (MOPs), tiny punctures made in the jawbone beside the tooth, low-level laser therapy (LLLT), and the two combined were compared with untreated control sides in a 2018 clinical trial at a dental faculty in Egypt to assess the rate of orthodontic tooth movement. 30 patients were divided into 3 groups of 10, each patient keeping 1 side of the mouth as a control while the other side received MOPs, LLLT at 800 to 820 nm and 500 mW/cm², or both, during canine retraction over 90 days. The trial found significant differences in the rate of canine retraction between each intervention and its control side. MOPs increased the rate 1.6-fold, LLLT 1.3-fold, and the combination 1.8-fold over the control side. The combination proved more efficient at speeding canine retraction than either technique on its own.

40% more canine movement on the laser side was the headline result of a 2017 split-mouth clinical trial at Istanbul University in Turkey on low-level laser therapy during canine distalization, the pulling back of the eye tooth into a premolar gap. 15 patients aged 12 to 19 with class II division 1 malocclusion had the upper first premolars removed, the right canine moved back by the standard protocol as a control, and the left canine moved back with laser applied. A gallium-aluminum-arsenide diode laser at 820 nm and 20 mW gave 5 doses from the cheek side and 5 from the palate side on days 0, 3, 7, 14, 21, 30, 33, 37, 60, 63, and 67, with 2 J per tooth at 5 J/cm². Gum crevice fluid was sampled over the first 21 days for interleukin-1β and TGF-β1, 2 signals of bone remodeling, and movement was measured on scanned models at 30, 60, and 90 days. Retraction reached 1.3 mm against 0.9 mm at 1 month and 3.9 mm against 2.77 mm at 3 months; interleukin-1β peaked on day 1, and the gums showed no inflammation throughout, the trial reported.

A double-blind, placebo-matched split-mouth design underpinned a 2016 randomized controlled trial at Erciyes University in Kayseri, Turkey, of light-emitting diode photobiomodulation therapy (LPT) on orthodontic tooth movement, the stability of anchorage miniscrews, and interleukin-1β in the gum and peri-implant crevice fluid. 20 patients, 13 girls and 7 boys, who had had the upper first premolars removed, received miniscrews between the first molars and second premolars on both sides as anchorage. The LPT side was treated with 618 nm light at 20 mW/cm² for 20 minutes per session over 21 days, according to the protocol columns, while the other side received a placebo. Miniscrew stability was similar on both sides at baseline and 1 month but significantly higher on the LPT side at 2 and 3 months, and the trial found tooth movement significantly greater on the LPT side at every interval. Interleukin-1β did not change significantly between the sides, and the authors saw in LPT the potential to accelerate orthodontic tooth movement while helping anchorage screws stay firm.

9 of 173 studies retrieved from 7 databases, 6 randomized and 3 quasi-randomized trials with 211 patients from 6 countries, were pooled in a 2015 systematic review and meta-analysis from Sichuan University in Chengdu, China, on low-level laser therapy (LLLT) for faster orthodontic tooth movement. 2 reviewers ran the searches, extracted the data, and graded the risk of bias, rating 5 trials moderate and 4 high. The pooled outcome was the total distance teeth moved. According to the abstract, LLLT accelerated orthodontic tooth movement at 7 days by 0.19 mm, and at 2 months by 1.08 mm, both statistically significant. A relatively low energy density of 5 to 8 J/cm² seemed more effective than 20 to 25 J/cm² or higher.

Low-intensity laser appeared to add 0.42 mm a month to canine retraction once treatment passed 3 months, according to a 2014 systematic review and meta-analysis from the University of Bern in Switzerland on surgical and non-surgical ways of speeding orthodontic tooth movement. 18 randomized and controlled clinical trials with 354 participants were found in searches updated to March 2014: 8 on low-intensity laser, 1 on photobiomodulation, 1 on pulsed electromagnetic fields, 7 on corticotomy, and 1 on interseptal bone reduction. Only the 2 laser trials and 2 corticotomy trials with low or unclear risk of bias were pooled with a random-effects model. Corticotomy, a surgical scoring of the bone, sped canine retraction in the first month, while the laser effect showed in the longer term, with the quality of evidence rated moderate for laser and low for corticotomy. The reviewers concluded that there is some evidence for laser therapy and corticotomy, weak evidence for interseptal bone reduction, and very weak evidence for photobiomodulation and electromagnetic fields, all to be read with caution given the small number and mixed quality of trials.

11.7% relapse with low-level laser therapy (LLLT) against 27.8% without any treatment was the finding of a 2014 randomized controlled trial at Mashhad University of Medical Sciences in Iran on rotated upper incisors. 24 patients finishing orthodontic treatment, each with at least 1 upper incisor rotated 30 to 70 degrees before correction, were divided into 4 groups: conventional fiberotomy, fiberotomy aided by an Er:YAG laser at 2940 nm, LLLT at 810 nm, and control. Fiberotomy, which cuts the gum fibers that pull a tooth back toward its old position, is the standard way to maintain corrected rotation; here, the archwire was removed from the treated incisors so they could relapse, with rotation measured on models 1 month later. Relapse was 9.7% after conventional fiberotomy and 12.7% after the laser-aided version, and the 3 treated groups appeared no different from each other. LLLT at its high energy density therefore held the corrected orthodontic tooth movement as well as surgery did, at least in the short term, with less pain than conventional fiberotomy.

In 2013, a split-mouth clinical trial at Hacettepe University in Ankara, Turkey, tested low-level laser therapy (LLLT) on the speed of orthodontic tooth movement and on nitric oxide, a signaling molecule, in the fluid of the gum crevice. 20 patients, 14 girls and 6 boys, had the upper first premolars removed and the canines moved back, and the upper lateral incisors were then retracted, with the right incisor irradiated and the left as a control. A gallium-aluminum-arsenide diode laser at 808 nm and 20 mW delivered 10 doses of 0.71 J/cm², 5 from the cheek side and 5 from the palate side, on days 0, 3, 7, 14, 21, and 28. Gum fluid was sampled on the same days for nitric oxide. The trial found that LLLT accelerated orthodontic tooth movement significantly, while nitric oxide levels in the gum fluid showed no significant change during treatment.

Following 15 patients aged 14 to 23 through canine retraction in both jaws, a 2008 clinical trial at a dental school in Syria evaluated a low-level GaAlAs diode laser for faster orthodontic tooth movement and less pain. Each patient had the upper and lower first premolars removed for crowding or protrusion, braces fitted 14 days later, and the eye teeth pulled back on prefabricated springs in both jaws. The right side of each jaw was irradiated with 809 nm light at 100 mW and 8 J/cm² in contact with the gum for 10 to 20 seconds per point, in 4 sessions over 180 days, while the left side served as a control. Pain was graded from none to intolerable at each stage. The researchers reported that low-level laser therapy greatly accelerated tooth movement and effectively reduced pain, with the jaw-treated side making no significant difference in speed.

When 11 patients had their upper canines retracted over 2 months in 2004, a clinical trial at a laser research center in São Paulo, Brazil, became the first to test low-intensity laser therapy (LILT) on the speed of orthodontic tooth movement in humans. Half of each upper arch served as a control and had the canines activated mechanically every 30 days. The other half had the same activation plus a 780 nm diode laser at 20 mW and 5 J/cm² for 10 seconds at a point on 4 days each month. Progress on both sides was measured and compared statistically. All 11 patients showed a significantly higher rate of canine retraction on the laser side than on the control side, which suggests that LILT does accelerate human tooth movement and could considerably shorten the whole course of orthodontic treatment, the authors wrote.

Low-level laser therapy (LLLT) shows promise for speeding orthodontic tooth movement and may reduce pain, a 2025 scoping systematic review from the University of Sharjah in the United Arab Emirates reported. The reviewers searched 4 databases for randomized controlled trials published between January 1990 and November 2023 on 3 adjuncts to fixed orthodontic treatment: LLLT, vibration therapy, and probiotics. They focused on how each adjunct affects the inflammation of gum and bone that orthodontic tooth movement provokes, the pain patients feel, and treatment duration. In the reviewers' judgment, LLLT accelerates movement, but the trials disagree enough to call for standardized application protocols. Vibration therapy was rated inconclusive, since a few trials found faster movement and most did not, and probiotics were seen as promising for the oral microbiota and inflammation but needed more rigorous study.

Researchers in Saudi Arabia reviewed low-level laser therapy (LLLT) as an adjunct to accelerated orthodontics in a 2024 narrative review covering its mechanism, procedure, efficacy, safety, advantages, limitations, and future scope. The review explains that the light is absorbed in the mitochondria of cells around the tooth, raising cellular energy and bone remodeling that lets a tooth move through the jaw. Of the clinical trials it discusses, most found faster orthodontic tooth movement with the laser, including a 34% gain in canine retraction with 780 nm light, while 3 small trials of 10 to 12 patients found no significant difference. According to the review, no adverse effects on teeth or supporting tissues have been reported, and the laser also lowered pain in the trials it cites. The authors concluded that current research broadly supports LLLT for speeding tooth movement, but that agreed protocols and larger randomized trials are still needed before it is widely adopted.

Whether adding 1 or more acceleration methods to self-ligating brackets, braces that hold the wire without elastic ties, speeds orthodontic tooth movement in adults was the question of a 2022 systematic review from a dental faculty in Syria. Searches of 4 databases and 2 trial registries from January 1990 to November 2021 found 1367 references, of which 7 randomized controlled trials and 1 controlled clinical trial were included and rated with the Cochrane risk-of-bias tool. Combining brackets with flapless corticotomy, surgical bone scoring, low-level laser therapy (LLLT), or infrared light accelerated movement by 43% to 50%, 20% to 50%, and 22%, respectively, while adding vibration did not speed movement at all. None of the acceleration methods harmed the gums or supporting tissues. Self-ligating brackets with surgery, laser, or infrared light were judged to speed orthodontic movement by 20% to 50% in all.

Adolescents with an average age of 16.35 were the patients in a 2021 split-mouth clinical trial at a university in Turkey that compared low-level laser therapy (LLLT) with piezocision, small surgical cuts in the gum and bone, for speeding orthodontic tooth movement. In 20 patients, 40 upper canines were distalized against miniscrew anchorage, with piezocision on the right canine and a 940 nm diode laser at 400 mW and 5 J/cm² for 80 seconds on the left over 28 days. Canine movement was measured over 4 time intervals up to 12 weeks, with cephalometric checks of canine and molar angulation. Researchers found that the laser side moved significantly further in the first interval, while no significant difference between the sides appeared in the later intervals or over the whole 12 weeks. Movement in both groups was greatest in the first period, and the authors judged the 2 methods similar over 12 weeks despite the laser's early lead.

6 doses of 670 nm laser light in the first 2 weeks, 9 minutes each on days 0, 1, 2, 3, 4, and 7, were tested against a sham application in a 2015 split-mouth clinical trial in Spain. 10 volunteers fitted with braces from the upper first premolars to the upper first molars had 1 first premolar irradiated at 200 mW and 6.37 W/cm² on 3 sides of the tooth, while the opposite premolar had the tip inserted with no emission. Gum crevice fluid was sampled at baseline and at 2, 7, 30, and 45 days for RANKL and osteoprotegerin (OPG), 2 proteins that control bone breakdown, and tooth movement was read from scanned models, with pain rated on a self-rated scale. Pain, tooth movement, and the RANKL readings all appeared better on the laser side, but the differences were not statistically significant. Only the accumulated retraction of the premolar at 30 days was significantly higher with the laser, so repeated LLLT led to a slight orthodontic improvement at most.

Researchers at the laser research center of Shahid Beheshti University of Medical Sciences in Iran published a literature review in 2015 on how low-level laser therapy (LLLT) alters orthodontic tooth movement. Studies published between January 2009 and August 2014 were gathered from PubMed, ScienceDirect, Google Scholar, and the grey literature, and study design, sample size, wavelength, power, and duration were extracted from each. Some investigators were found to report significantly more tooth movement on the irradiated side by the end of their experiments, which the reviewers attribute to faster bone remodeling from stimulated bone-forming and bone-resorbing cells. Others reported no difference between low-energy and high-energy irradiation and control sides, and some found that laser irradiation can reduce orthodontic tooth movement. The review suggests that this inhibitory effect could be used to reinforce anchorage teeth that must not move.

Injectable platelet-rich fibrin (i-PRF) outpaced low-level laser therapy (LLLT) for closing extraction spaces in a 2025 split-mouth randomized controlled trial at a dental college in Maharashtra, India. 20 patients aged 18 to 25 who needed both upper first premolars removed were assigned at random to 2 groups of 10, with the left sides serving as controls. 1 group had i-PRF injected into the ligament and under the gum on the right side, and the other had a 980 nm laser at 100 mW and 1 J/cm² applied to the right canine for 10 seconds at a time. Space closure between the canine and second premolar was measured monthly for 4 months. The i-PRF side was reported to close 2.85 mm against 2.05 mm on the laser side, a significant difference, while the laser side did not differ from its own control, so i-PRF was judged more effective than LLLT at accelerating orthodontic tooth movement.

According to a 2022 systematic review and meta-analysis from a university in Mexico, the trials of photobiomodulation (PBM) for shortening orthodontic treatment with fixed braces are of very low quality. 22 studies with 515 participants, randomized and non-randomized trials in English or Spanish, were found in 4 databases, with their data extracted by 2 authors independently and the risk of bias graded with standard tools. The included trials used low-level laser or LED light at 572 to 980 nm, and all of them carried a high risk of bias or some concerns; none had a low risk. Pooled with a random-effects model, the extra orthodontic tooth movement with the light was 0.50 mm at 1 month, 1.40 mm at 2 months, and 0.46 mm at 3 months, with only the 2-month figure clear of no effect. The reviewers concluded that there is no evidence to support low-level laser for speeding orthodontic movement, and that the LED trials are too few to draw any conclusion.

No difference in the distance or speed of molar intrusion, the orthodontic tooth movement that pushes an over-erupted molar back into the jaw, separated the light group from the control group in a 2021 randomized controlled trial at a university in Spain. 20 adults whose upper first molar had over-erupted after losing the opposing tooth were randomized to intrusion on miniscrew anchorage alone or the same plus photobiomodulation (PBM) from a 670 nm red diode laser at 150 mW, 4780 mW/cm², and 108 J for 12 minutes. The light was given on days 0, 1, 2, 3, 4, and 7, and at each monthly follow-up over 180 days, with plaque, probing depth, and gum bleeding assessed at 6 months, and 3D scans and cone-beam CT used to measure intrusion and root resorption. Gum measures and intrusion did not differ, although the PBM group tended to score lower on all of them in the first 3 months. Root resorption was less in the PBM group without reaching significance, so PBM may give better gum health and slower root loss at the cost of slightly less intrusion.

No extra canine retraction came from adding low-level laser therapy (LLLT) to corticotomy in a 2019 split-mouth randomized controlled trial at Cairo University in Egypt. Corticotomy, in which the outer bone around the teeth is scored surgically to speed orthodontic tooth movement, was performed on both sides of the upper jaw in 16 female patients. 1 side then received an indium-gallium-arsenide diode laser at 940 nm and 500 mW/cm², 5 J/cm² for 4 minutes per session, over a retraction period of 120 days, while the other side had corticotomy alone. The rate of upper canine retraction with the combined treatment was not significantly different from that with corticotomy alone. The conclusion drawn was that LLLT cannot raise the rate of orthodontic canine retraction above what corticotomy, the reference technique, already achieves, and that neither approach left long-term harm to the gum lining over the bone.

Among 11 female patients aged 14 to 25 who needed their canines retracted after premolar extraction, a 2016 randomized controlled trial, split-mouth and double-blind, in Yazd, Iran, tested low-level laser irradiation on the rate of orthodontic tooth movement. A gallium-aluminum-arsenide diode laser at 980 nm and 100 mW delivered 5.6 J/cm² to the canine in 1 upper quadrant, with a sham application on the other, on days 0, 7, 14, 21, and 28 of each month over an 11-month study. Interleukin-6, an inflammatory signal of bone remodeling, was measured in the gum crevice fluid alongside the movement. The canines moved back slightly faster on the laser side but not significantly so, and interleukin-6 did not differ between the sides at any stage. The authors concluded that conclusive evidence could not be provided for a 980 nm diode laser accelerating orthodontic tooth movement in women.

A 2016 systematic review and meta-analysis from the Federal University of Sergipe in Brazil asked whether low-level, low-energy-density laser therapy speeds orthodontic tooth movement after first premolar extraction. 161 articles were found in 6 databases with no date or language limit, and only randomized clinical trials that used first premolar extraction and low energy densities were kept, leaving 6 for the qualitative review and 5 for pooling with a random-effects model. Most of the included trials were rated high quality on the reviewers' checklist. 3 of the trials had found a significant difference in movement between laser and control groups, and the pooled analysis showed a significant laser effect in the upper jaw at 3 months and in the lower jaw at 1 month. No evidence was found to prove that laser therapy accelerates orthodontic tooth movement, and larger randomized trials are needed to strengthen the evidence either way.

Applying an 880 nm diode laser at 100 mW and 5 J/cm² to 8 points for 80 seconds on 1 canine only, a 2015 double-blind randomized controlled trial in Iran tested whether low-level laser therapy speeds orthodontic tooth movement and eases its pain. 12 orthodontic patients who needed their first premolars removed were selected at random, with 1 side of the mouth irradiated and the other left as a control. After leveling and alignment, 150 g of force was applied to each canine through sectional closing loops activated every month, and movement and pain were recorded on days 1, 3, 7, 30, 33, 37, 60, 63, and 67. No significant difference in tooth movement or pain scores appeared between the irradiated and non-irradiated sides at any time point. The authors concluded that although the laser enhanced movement in the upper jaw, they could not provide solid evidence that it speeds orthodontic tooth movement or reduces the pain that goes with it.

Whether an LED device could speed orthodontic tooth movement was the question a 2015 split-mouth randomized controlled trial at the University of Toronto set out to answer. 17 dental arches from 11 orthodontic patients who had had premolars removed on both sides were included, and during closure of the extraction spaces the LED light was applied to 1 side of each arch while the other side served as a control. The device emitted near-infrared light in the 780 to 1400 nm range for 21 minutes a day over 90 days, and space closure was measured just before, during, and later in the closure phase. According to the abstract, every participant kept to the LED schedule, yet no significant change in the rate of orthodontic tooth movement appeared over the 3 months of space closure. The result ran contrary to earlier laser findings, and the authors called for work on whether the duration or method of LED delivery makes a difference.

10 patients whose upper canines were irradiated on 1 side with a 904 nm gallium-arsenide laser showed no faster retraction on that side in a 2014 clinical trial at a dental institute in Himachal Pradesh, India. 1 quadrant of the upper arch served as a control and had the canine activated with 150 g of force, while the opposite quadrant had the same activation plus 10 seconds of laser at 12 mW and 4.2 J/cm². The laser was applied on days 1, 3, 7, 14, 21, 28, 35, 42, 49, and 56 of the retraction phase, with the distance measured on days 1, 35, and 63 and radiographs taken to check the irradiated area. Canine movement from day 1 to day 63 averaged 3.30 mm on the control side and 3.53 mm on the laser side, a difference the trial found not statistically significant. Radiographs showed no pathological change around the irradiated teeth, so low-intensity laser therapy appeared safe but did not speed orthodontic tooth movement at these settings.

Researchers at Mashhad University of Medical Sciences in Iran tested an 810 nm gallium-aluminum-arsenide laser on the speed of canine retraction and on pain in a 2014 single-blind split-mouth clinical trial. 20 patients who needed both upper first premolars removed had 1 half of the upper arch irradiated at 200 mW and 21.4 J/cm² at 10 points, with the other half as placebo. The laser was applied as soon as the retraction force was loaded and on days 3, 7, 11, and 15 of the first month, then repeated after the coil spring was adjusted on day 28, with models taken at 0, 28, and 56 days. The distance the canines moved and their tilt did not differ significantly between the laser and placebo sides, and neither did the pain patients felt when biting on plastic blocks at any appointment. The conclusion drawn was that LLLT at these settings did not affect the speed or tilt of orthodontic tooth movement or the pain patients perceived.

According to a 2006 double-blind randomized placebo-controlled trial from Khon Kaen University in Thailand, gallium-aluminum-arsenide low-level laser therapy (LLLT) at 25 J/cm² did not change the rate of orthodontic tooth movement. 12 young adults, 4 men and 8 women, about 20 years old, had both upper first premolars extracted at least 3 months earlier, and their canines pulled back into the spaces with coil springs at 150 g on fixed braces. An 860 nm laser at 100 mW was applied for 23 seconds per point, 2.3 J per point, to the gum on the cheek side, palate side, and behind the canine on 1 side, with a sham application on the other. Each course ran 3 days and was repeated at the end of each of the first 3 months, with dental casts measured monthly under a stereo microscope. The canine movement on the laser side appeared no different from the placebo side at any time, and the investigators reasoned that the energy density at the surface was probably too low to either stimulate or inhibit tooth movement.