ORIGINAL RESEARCH

https://doi.org/10.5005/jp-journals-10015-2287
World Journal of Dentistry
Volume 14 | Issue 9 | Year 2023

Effect of Laser-induced Photobiomodulation on Orthodontic Tooth Movement: A Clinicoradiographic Study

Mohd Amir¹, Mohsin A Wani², Diptiman Shukla³, Rakesh Koul⁴, Shashank Trivedi⁵, Shikha Sangal⁶

^1,2,4-6Department of Orthodontics and Dentofacial Orthopaedics, Career Post Graduate Institute of Dental Sciences and Hospital, Lucknow, Uttar Pradesh, India

³Banaras Hindu University, Varanasi, Uttar Pradesh, India

Corresponding Author: Mohsin A Wani, Department of Orthodontics and Dentofacial Orthopaedics, Career Post Graduate Institute of Dental Sciences and Hospital, Lucknow, Uttar Pradesh, India, Phone: +91 9858343239, e-mail: mohsynaslam@gmail.com

Received on: 06 August 2023; Accepted on: 07 September 2023; Published on: 13 October 2023

ABSTRACT

Aim: To determine, if any, the percentage impact of low-level laser therapy (LLLT) administration on the length of orthodontic treatment and to test the hypothesis that the pace of orthodontic tooth movement (OTM) is accelerated when mechanical forces are paired with LLLT.

Materials and methods: In this study, 10 healthy orthodontic patients were selected consisting of five men and five women. A split-mouth design was used for the examination. The right and left quadrants were randomly designated as two groups. Group I served as the control side and group II represented the experimental side. Irradiation of the tissues was performed with a laser device having a continuous wavelength of 980 nm, an output power of 100 mW, a dose of 10 J/cm², and an exposure time of 10 seconds. Segmental T-Loop (17 × 25 TMA wire) was used for canine retraction. In the 1st month, laser therapy was performed on days 0, 1, 3, 7, and 14. Subsequent irradiations were carried out on the experimental side every 15 days until full extraction space closure.

Results: The study revealed a greater net decrease in the mean distance between the canine and first molar in the maxilla in combination with the faster rate of maxillary canine retraction. For the intragroup comparison as well as the intergroup comparison, using the Chi-squared (χ2) test, for each period, the difference in the probing depth (PD) score (PD 1–2/2–3 mm) showed an insignificant (p > 0.05) difference. Moreover, the radiographic evaluation showed an overall decline in trabecular percentage in both the maxillary and the mandibular extraction spaces.

Conclusion: Low-level laser treatment (LLLT) statistically boosts the orthodontic movement of the canines during the first retraction phase. The study’s irradiation settings and procedure were successful in reducing treatment time.

Clinical significance: With the potential to shorten the course of treatment, LLLT is a superb adjunct treatment option for orthodontic care.

How to cite this article: Amir M, Wani MA, Shukla D, et al. Effect of Laser-induced Photobiomodulation on Orthodontic Tooth Movement: A Clinicoradiographic Study. World J Dent 2023;14(9):783–790.

Source of support: Nil

Conflict of interest: None

Keywords: Biostimulation laser therapy, Cold laser therapy, Canine retraction, Low-energy laser therapy, Low-intensity laser therapy, Low-level laser therapy, Low-power laser irradiation, Low-power laser therapy, Orthodontic tooth movement, Photobiomodulation therapy, Probing depth, Soft laser therapy

INTRODUCTION

The movement of teeth in anticipation of the applied light forces is the fundamental concept of orthodontics. To avoid root disintegration and necrosis of its supporting osseous structures, light mechanical forces are indicated. As a result of this, therapy for orthodontics takes greater time to complete.¹^,²

Numerous techniques, including nonsurgical (ultrasound waves and electric current), surgical (alveolar corticotomies and distraction), and drug-mediated therapies (parathyroid hormones, osteocalcin, and prostaglandin injection), have been proposed to shorten the period of therapy by promoting bone remodeling process. While surgical procedures are invasive and have certain limitations, pharmaceutical approaches are not very promising and can cause discomfort at the injection site or sophisticated equipment that requires prolonged use to have therapeutic effects.³^-⁶

Because of its limited invasiveness and reliability, physical modalities such as low-level laser therapy (LLLT) have been deemed a preferable alternative for reducing the time spent on treatment.⁷

Photobiomodulation therapy (PBMT) is a scientific term for LLLT that employs the use of light-emitting diodes or lasers to accelerate the tissue healing process while overcoming the patient discomfort brought on by pain and inflammation wherever the beam is applied. The terms “low-power laser therapy,” “soft laser therapy,” “low-intensity laser therapy,” “low-energy laser therapy,” “cold laser therapy,” “biostimulation laser therapy,” and “photobiomodulation” are all terms that have been used to refer to variations of LLLT.⁸–¹¹

In the discipline of orthodontics, LLLT has proven effective in biomodulation, with depressant effects on analgesia and stimulant effects on tissue healing. These stimulatory effects are brought about by LLL’s ability to speed up metabolic changes in skeletal tissue and to stimulate rapid bone resorption and neoformation, both of which are required for orthodontically induced tooth movement. More recently, several researchers have examined the impacts of LLLT and discovered that because it stimulates alveolar bone remodeling without harming the tooth or periodontium, LLLT has stimulatory effects that can speed up tooth movement.¹²^-¹⁴ By altering the enzymatic levels of transforming growth factor-1, cyclooxygenase-2, prostaglandin E2, fibronectin, collagen turnover, and preservation of tissue perfusion, low-intensity laser therapy can affect osteoclast control.¹⁵ These enzymes alter the development, maturation, and maintenance of osteoclasts by inducing the expression or inhibition of components of the osteoprotegerin/receptor activator of nuclear factor κ B ligand/receptor activator of nuclear factor κ B system.¹⁶^,¹⁷

Hence, the present research was undertaken to validate the efficacy of LLLT and aimed at comparing the amount and rate of orthodontic tooth movement (OTM) achieved when exposed to diode laser irradiation, while maintaining the integrity of the periodontal tissues.

MATERIALS AND METHODS

A split-mouth double-blind randomized study design was used for the clinical investigation. Since our experimental study involves human subjects, a larger sample size is a crucial ethical issue that can expose the subjects to potentially damaging therapies without advancing knowledge. A sample size of 10 healthy orthodontic patients was selected, sufficient for the study to have an ideal of 80% power and be clinically significant. The sample consisted of five men and five women who needed extraction of mandibular and maxillary first premolars. Patient consent was signed by all the subjects and due ethical clearance as per the university protocol (IEC approval number: CPGIDSH/968/19) was obtained. The study was conducted in the year 2018 for 6 months. All the patients received good dental hygiene advice before initiating the clinical research and in each patient, the right and left sides across the midline were randomly designated as two groups and were concealed from the patients. Group I served as the control side and was not subjected to any laser therapy whereas, group II underwent LLLT and represented the experimental side. The patients reporting to the Department of Orthodontics and Dentofacial Orthopaedics, Career Post Graduate Institute of Dental Sciences and Hospital, Lucknow, Uttar Pradesh, India, were selected according to the following criteria.

Inclusion Criteria

Removal of either the maxillary or mandibular first premolars (or both) to allow correction of the front teeth.
No syndrome or cleft lip or cleft palate.
No history of orthodontic treatment or maxillofacial surgery.
No maxillary sinus pathology.
Radiographs with good quality and detail.

Exclusion Criteria

Patients with a history of long-term medication with nonsteroidal anti-inflammatory medicines and exogenous hormonal compounds were excluded from the study, due to their implications on bone metabolism. Individuals with skeletal crossbites, parafunctional behaviors, and occlusal discrepancies were also disqualified.
Periodontically compromised patients were not included because poor bone quality can alter how teeth move during orthodontic treatment and mobility development can result in inaccurate measurements.
Dilacerated roots on canines make them difficult to move during orthodontic treatment and increase the risk of root resorption, hence they were omitted from the study along with impacted canines.

All the patients included in the present study underwent the orthodontic camouflage treatment involving segmental mechanotherapy and the extraction of first premolar teeth. Preadjusted edgewise McLaughlin Bennett Trevisi (MBT) brackets of the 0.022-in slot were used. After stage I (leveling and alignment), a segmental T-Loop (17 × 25 TMA wire) was used to begin individual canine retraction. Steel ligature wires measuring 0.009 inches were used to consolidate the incisors. In order to create a single anchorage unit, the first molar and second premolar were also combined. On initiation of the canine retraction process on both the control and experimental sides, a steady 150 gm force was applied and measured using a Dontrix gauge. While uniformly maintaining all the other parameters of the treatment process and nullifying methodological disparity, the same operator performed all of the radiation treatments with the laser device having a continuous wavelength of 980 nm, an output power of 100 mW, a dose of 10 J/cm, and an exposure time of 10 seconds (Figs 1A and B). The handpiece’s 4 mm surface area cylindrical quartz tip is where the laser beam is released. Sterilization and disinfection were performed according to standard procedure. Cold sterilization was specifically used to clean the body of the handpiece and the optic tips. The patient and the operator both wore safety eyewear (Fig. 1C). On the day the T-Loop was implanted, LLLT was begun for analgesia, and 10 irradiations were carried out in total, five on the buccal side and five on the palatal side. The following distribution and order were used to fully encircle the periodontal fibers and alveolar process around the canines. On the buccal side, the canine root’s cervical and apical thirds, each received two irradiation doses (one mesial and one distal). A single irradiation was given on the middle third (center of the root). The radiation treatments were carried out identically on the palatal side (Fig. 2). Throughout the application, the tip was kept in juxtaposition with the tissue. Each application had a total energy density (dose) of 10 J (2 × 10 seconds × 100 mW). For all appointments after that, this process was used. In the 1st month, the course of laser therapy was performed on days 0, 1, 3, 7, and 14. After that, irradiations were carried out on the experimental side every 15 days until full extraction space closure. Periapical radiographs of the canines on the experimental side and the control side were taken after 6 months and they revealed no unfavorable alterations in the surrounding periodontium (Figs 3A and B). Pulp vitality tests to determine the health of the retracting canines were likewise successful. Models were made for every patient. The mesial cusp tips of the canine and the first molar served as reference points on the models. A digital caliper was used to measure each patient’s first molar to canine distance on all the models (Figs 3C and D). The primary outcome measure of the study was the distance between canine and first molar (mm) and the secondary outcome measures of the study were probing depth (PD) and radiographic evaluation.

Figs 1A to C: (A) Diode laser device; (B) Manufacturer recommendations; (C) Protective eyewear

Fig. 2: Diode laser procedure in following sequence. Maxilla (Ia-Ib, cervical mesial; IIa-IIb, cervical distal; IIIa-IIlb, middle; IVa-IVb, apical mesial, Va-Vb, apical distal). Mandible (VIa-VIb, cervical mesial; VIIa-VIIb, cervical distal; VIIIa-VIIIb, middle; IXa-IXb, apical mesial; Xa-Xb, apical distal)

Figs 3A to E: (A and B) Radiographic analysis of trabeculae distal to canine; (C and D) Measurements on the study model using a digital caliper, before and after the canine retraction; (E) Measuring changes in PD

Distance between Canine and First Molar

The amount and rate of tooth movement were determined using the distances measured at T0 (the day after alignment and leveling, the 1st day of canine retraction), T1 (3 months after the start of canine retraction), and T2 (the conclusion of canine retraction on the experimental side). Three measurements were taken for each distance, and the mean value was noted.

Probing Depth (PD)

The light pressure of 10–20 gm was applied to the instrument’s tip as it was introduced into the gingival sulcus parallel to the shape of the tooth’s root and down to the base of the pocket. The depth of the first marking that was visible above the pocket was measured and noted (Fig. 3E).

Score 1: When the depth of the probe is 1–2 mm.
Score 2: At a depth of 2–3 mm.
Score 3: If the depth of the probe is greater than 3 mm.

The evaluation was conducted bilaterally to the canine both in the maxillary and mandibular arch.

Radiographic Evaluation

The alveolar bone’s trabeculation was assessed using the next visual assay:

Score 1: Sparse—few bone marrow cells exist, particularly in the cervical areas.
Score 2: Dense-sparse—the trabeculation is dense apically but sparse in the cervical areas.
Score 3: Dense—the area contains a similar amount of trabeculation throughout, and the bone marrow gaps are modest.

The evaluation was conducted bilaterally, distal to canine both in the maxillary and mandibular arch.

The continuous data were summarized in mean ± standard error (SE) of the mean. Continuous paired (dependent) groups were compared by paired t-test. Continuous dependent groups were also compared by repeated measures of two factors (groups and periods), analysis of variance, and the significance of mean difference within (intra) and between (inter) the groups were done by Tukey’s honestly significant difference post hoc test after ascertaining normality by Shapiro–Wilk test and homogeneity of variance by Levene’s test. Categorical (discrete) groups were summarized in number (n) and percentage (%) and compared by the Chi-squared (χ2) test. A two-tailed (α = 2) p < 0.05 was considered statistically significant. Analyses were performed on Statistical Package for the Social Sciences software (Windows version 17.0).

RESULTS

The present clinicoradiographic study evaluates and compares the efficacy of laser-induced photobiomodulation on OTM. All the patients selected in the study were randomized, the left side was treated without laser therapy (control, n = 10) and the right side with LLLT (experimental, n = 10).

Maxilla: Evaluating Rate of Canine Retraction, PD, and Radiographic Characteristics

The distance (mean ± SE) between canine and first molar over the periods T0, T1, and T2 of the control side was 21.71 ± 1.80 mm, 18.45 ± 1.89 mm, and 15.78 ± 1.58 mm and of the experimental side was 21.70 ± 1.74 mm, 17.00 ± 2.13 mm, and 13.53 ± 1.16 mm (Table 1 and Fig. 4), respectively. For each group, comparing the difference in mean distance between canine and first molar between the periods (i.e., intragroup), the Tukey test showed a significant (p < 0.001) decrease in distance between canine and first molar at both T1 and T2 as compared to T0 in both groups. Further, in both groups, it also decreases significantly (p < 0.001) at T2 as compared to T1. Similarly, for each period, comparing the difference in mean distance between canine and first molar between the groups (i.e., intergroup), the Tukey test showed insignificant (p > 0.05) difference in distance between canine and first molar between two groups at all periods, that is, found to be statistically the same. However, the net decrease in mean distance between canine and first molar (i.e., mean change or decrease from T0 to T2) of the experimental group (37.7%) was found to be 10.4% higher as compared to the control group (27.3%). Also, the rate of retraction of the maxillary canine on the experimental side (1.81 mm/month) was 27.7% faster than the control side (1.31 mm/month), as shown in Table 2.

**Table 1:** Distance between canine and first molar (mm) (mean ± SE) of two groups over the periods at the maxillary side
Time period	Control (n = 10)	Experimental (n = 10)
T0	21.71 ± 1.80	21.70 ± 1.74
T1	18.45 ± 1.89	17.00 ± 2.13
T2	15.78 ± 1.58	13.52 ± 1.16

Figs 4A to D: (A) Mean distance between canine and first molar (mm) of two groups over the periods at the maxillary side. The vertical bar denotes a 95% confidence interval (CI) of the mean; (B) The mean distance between canine and first molar (mm) of two groups over the periods at the mandibular side. The vertical bar denotes 95% confidence interval (CI) of the mean; (C) Distribution of the radiographic evaluation score of two groups over the periods at the maxillary side; (D) Distribution of the radiographic evaluation score of two groups over the periods at mandibular side

**Table 2:** Rate of maxillary canine tooth movement
Time period	T0–T1 (after 3 months)	T0–T2 (after 4.5 months)
Control	1.08 mm/month	1.31 mm/month
Experimental	1.56 mm/month	1.81 mm/month

For each period, comparing the difference in PD score (PD 1–2/2–3 mm) between two groups (i.e., intragroup), χ2 test showed an insignificant (p > 0.05) difference in PD score between the groups at all periods. Also, for each group, comparing the difference in PD score (PD 1–2/2–3 mm) between periods (i.e., intergroup), χ2 test showed insignificant (p > 0.05) difference in PD score between periods (T0 vs T1: χ2 = 0.83, p = 0.361; T0 vs T2: χ2 = 3.20, p = 0.074; T1 vs T2: χ2 = 0.83, p = 0.361) in both the groups.

The radiographic evaluation score (sparse) decreases by 30% from T0 to T2 in both groups (Graph 3). For each period, comparing the difference in radiographic evaluation score between two groups (i.e., intragroup), χ2 test showed an insignificant (p > 0.05) difference in radiographic evaluation score between the groups at both periods. Similarly, for each group, comparing the difference in radiographic evaluation score between periods (i.e., intergroup), χ2 test showed a significant (p < 0.05) change in radiographic evaluation score between periods (T0 vs T2: χ2 = 8.33, p = 0.016) in both the groups.

Mandible: Evaluating Rate of Canine Retraction, PD, and Radiographic Characteristics

The distance (mean ± SE) between canine and first molar over the periods T0, T1, and T2 of the control side was 18.98 ± 0.87 mm, 16.54 ± 0.81 mm, and 14.55 ± 0.68 mm and of the experimental side was 18.78 ± 1.00 mm, 15.37 ± 1.09 mm, and 12.76 ± 0.97 mm (Table 3 and Fig. 4), respectively. For each group, comparing the difference in mean distance between canine and first molar between the periods (i.e., intragroup), the Tukey test showed a significant (p < 0.001) decrease in distance between canine and first molar at both T1 and T2 as compared to T0 in both groups. Further, in both groups, it also decreases significantly (p < 0.001) at T2 as compared to T1. Similarly, for each period, comparing the difference in mean distance between canine and first molar between the groups (i.e., intergroup), the Tukey test showed an insignificant (p > 0.05) difference in distance between canine and first molar between two groups at both T0 and T1. In contrast at T2, it decreased significantly (p < 0.01) in the experimental group as compared to the control group. Moreover, the net decrease in the mean distance between the canine and first molar (i.e., mean change or decrease from T0 to T2) of the experimental group (32.1%) was found to be 8.7% higher as compared to the control group (23.3%). Furthermore, the rate of retraction of the mandibular canine on the experimental (1.33 mm/month) was 26.3% faster than on the control side (0.98 mm/month), as shown in (Table 4).

**Table 3:** Distance between canine and first molar (mm) (mean ± SE) of two groups over the periods at the mandibular side
Time period	Control (n = 10)	Experimental (n = 10)
T0	18.98 ± 0.87	18.78 ± 1.00
T1	16.54 ± 0.81	15.37 ± 1.09
T2	14.55 ± 0.68	12.76 ± 0.97

**Table 4:** Rate of mandibular canine tooth movement
Time period	T0–T1 (after 3 months)	T0–T2 (after 4.5 months)
Control	0.81 mm/month	0.98 mm/month
Experimental	1.13 mm/month	1.33 mm/month

For each period, comparing the difference in PD score (PD 1–2/2–3 mm) between two groups (i.e., intragroup), χ2 test showed insignificant (p > 0.05) difference in PD score between the groups at all periods, that is, did not differ significantly. Similarly, for each group, comparing the difference in PD score (PD 1–2/2–3 mm) between periods (i.e., intergroup), χ2 test showed insignificant (p > 0.05) difference in PD score between periods (T0 vs T1: χ2 = 0.83, p = 0.361; T0 vs T2: χ2 = 3.20, p = 0.074; T1 vs T2: χ2 = 0.83, p = 0.361) in both the groups.

The radiographic evaluation score (dense sparse) decreased by 50% from T0 to T2 in both groups (Fig. 4). For each period, comparing the difference in radiographic evaluation score between two groups (i.e., intragroup), χ2 test showed an insignificant (p > 0.05) difference in radiographic evaluation score between the groups at both periods. Similarly, for each group, comparing the difference in radiographic evaluation score between periods (i.e., intergroup), χ2 test showed a significant (p < 0.05) change in radiographic evaluation score between periods (T0 vs T2: χ2 = 8.92, p = 0.011) in both groups.

Comparing the Maxillary and Mandibular Changes

A relatively greater net decrease in the mean distance between the canine and first molar in combination with the faster rate of canine retraction was observed in the maxilla. This can be attributed to the increased vascularity and lower density of maxillary bone proper.

For each period, comparing the distribution of PD score between two sides, in both the mandible and in the maxilla (i.e., intergroup), χ2 test showed similar and insignificant (p > 0.05) differences in distribution of PD score between the two sides at all periods. In the intragroup comparison as well as the intergroup comparison, using the χ2 tests, for each period, the statistically insignificant (p > 0.05) difference in the PD score (PD 1–2/2–3 mm) may be attributed to the patient selection and maintenance of good oral hygiene by the patients throughout the period of the study as instructed. Also, for each period, comparing the distribution of radiographic evaluation score between the two sides in both mandible and in the maxilla (i.e., intergroup), χ2 test showed insignificant (p > 0.05) difference in the distribution of radiographic evaluation score between sides at all periods. In this investigation, the maxillary and mandibular canine PDs were measured both mesially and distally. According to a study by Listgarten, periodontal probing has been and is still one of the most effective diagnostic techniques for identifying the existence and degree of periodontal tissue. Periodontal probes are one of the more dependable and practical methods for identifying, quantifying, and evaluating the level of periodontal disease activity.¹⁸

In our study, we have used intraoral digital radiography for better quality and contrast. For each period, comparing the difference in radiographic evaluation score between two groups (i.e., control and experimental), the χ2 test showed an insignificant difference in radiographic evaluation score between the groups at both periods. But when comparing at different periods (T0–T2) of time sparse decreases by 30% in the maxilla and dense sparse decreases by 50% in the mandible. The probable reason may be due to the compression of trabeculae on the distal side of the canine during retraction.

During the early retraction period, the LLLT statistically increased the orthodontic movement of the canines, also, no canine root resorption alveolar bone ridge resorption, or any significant changes in PD of the supporting teeth was seen. This substantiates that LLLT is an effective and safe method for shortening treatment duration compared to treatment methods that do not employ laser therapy.

DISCUSSION

The length of the orthodontic treatment could be shortened, which would increase patient comfort and satisfaction while reducing the likelihood of negative effects. After the conception of how lasers could hasten wound healing and lessen pain, the notion of employing lasers to amplify tooth movement was born. Based on this fundamental premise, the present study was aimed to compare the scope and effectiveness of OTM brought about by the diode laser exposure. Several noninvasive techniques to improve bone tissue metabolisms, such as electric stimulation, USG, or LLLT, have been researched to reduce the dread of injection and avoid pain.¹² However, the biostimulatory benefits of LLLT on wound healing are its most well-known benefits and many studies have also described the benefits of LLLT on OTM.¹⁹ The noninvasive and clinically painless nature of the treatment with LLLT prompted us to employ and evaluate the practicality of this technique in our study. Moreover, the incorporation of the radiographical and periodontal parameters renders the distinctive approach used in the present study that is lacking in many of the previous studies reported in the literature, respectively.

The findings of Limpanichkul et al.²⁰ differed from ours. They concluded that no statistically significant difference was observed between the experimental LLLT subjects and the controls in a split-mouth study with 12 human subjects over 3-month periods. The probable reason for this could be the use of a laser diode with a smaller wavelength (860 nm), higher energy density (25 J/cm²), and greater exposure time (23 seconds/point), suggesting rather a bioinhibitory effect of this technical configuration.

Youssef et al. in 2007, using a split-mouth design in human subjects over 6 months, reported a rate of canine retraction in the experimental group (2.027 ± 0.114 mm/month) almost twice as fast as that of the control side (1.019 ± 0.110 mm/month),²¹ in contrast to 1.81 mm/month and 1.31 mm/month in our study. The reason could be the increased irradiation frequency of four times per month until the end of canine retraction compared with four times per month in the 1st month and two times per month in subsequent months in our study and also the total exposure duration of 40 seconds in comparison to only 10 seconds employed in our study.

A low-power Gallium Aluminium Arsenide (GaAIAs) 660 nm red laser improved the proliferation and osteogenic differentiation of human Periodontal Ligament (hPDL) cells through cyclic Adenosine Monophosphate (cAMP) modulation, according to the work by Wu et al. in 2013 in order to ascertain the effects and probable mechanism of low-power laser irradiation (LPLI) on PDL cells. Functional and genetic evidence showed that LPLI therapy may have osteogenic potential at 2 and 4 J/cm. According to their findings, periodontal tissue regeneration could potentially be improved with the noninvasive LPLI approach.²² To demonstrate its practical applicability, we employed low energy (maximum 10 J/cm²) laser therapy and observed a clinically significant increase in OTM, which may be attributed to the laser-induced proliferation and osteogenic differentiation of human hPDL cells through the cAMP modulation process.

In their study, Doshi-Mehta and Bhad-Patil in 2012, discovered that the rate of retraction of the maxillary canine on the experimental and control side was 1.46 mm/month and 0.65 mm/month in contrast to 1.81 mm/month, and 1.31 mm/month in our study. They observed that the average increase in tooth movement rates following canine retraction was 29% in the maxillary arch and 31% in the mandibular arch,²³ comparable to the 27.7 and 26.3% increase observed in the present study. Although not statistically significant, these differences in the upper and lower arch tooth movements, were nonetheless clinically thought-provoking. On the palatal side, the periodontal ligament of the canines is situated farthest from the area that was exposed to radiation, which may account for the lower gain in the maxillary arch.

According to the research conducted by Li-Fang et al. in 2018, 970 nm LLLT can boost bone turnover rate and decrease bone volume by practically a factor of two in experimental rat models. In the same context, LLLT can reduce relapse rates and boost bone growth in the area of the furcation. When LLLT treatments were administered every 3 days, they discovered that both the 1250 J/cm² and 15000 J/cm groups showed significantly higher OTM compared to the control group. According to their findings, the 970 nm LLLT increases the rate of OTM in a frequency and dose-dependent way.²⁴ In our investigation, we have used a similar laser with a 980 nm wavelength, 10 seconds exposure time, and initially on days 0, 1, 3, 7, and 14. Thereafter, a 15-day regimen was adopted as it falls within the time frame of typical recall visits. The outcome of our study is in accordance with the results observed in the above research, as the rate of extraction space closure as well as the rate of canine retraction was increased by employing a laser therapy with modest wavelength and energy indicating a higher OTM compared to the control group.

In a 2019 study, Elkattan et al. found that the rate of tooth movement in an experimental animal study was highest in group III (low dose: 10–55 J). Statistically, there was no significant difference (p1 = 0.67) between group I (control) and II (high dose: 20–110 J). However, a significant difference (p2 = 0.001) between groups II and III and also between groups I and group III (p3 = 0.002) were observed.²⁵ The results indicated that LLLT at low doses can speed up orthodontic tooth movement in agreement with the inference of the present study, however, LLLT at large doses was unable to provide the same results.

In the future, LLLT can be used for improving the primary stability of implants, enhancing the healing properties of extraction sockets, and facilitating faster orthodontic tooth movement through the laser-treated grafted site. When a novel treatment approach is suggested, care must be taken to prevent injury to host tissues. Experimental studies to optimize radiation variables and find more benefits that are encouraged, as well as additional research to elucidate the processes of laser biomodulation, are needed.

Limitations of the Study

Along with variations in force, laser beam irradiations follow different procedures. There is no set protocol, dosage, or regularity for utilizing LLLT to guide teeth during orthodontic treatment. It is almost difficult to assess the immediate and long-term effects of laser treatments on tooth movement during orthodontics given the limitations of this investigation.

CONCLUSION

The irradiation parameters and technique of our study were effective in cutting down on treatment time. Orthodontic tooth mobility is physiologically accelerated by low-intensity laser therapy. It has no negative effects on the periodontium or the health of the tooth. So, it can be used regularly and safely throughout the orthodontic treatment. A successful form of analgesia during orthodontic treatment is low-intensity laser therapy which is an excellent supplemental treatment option for orthodontic care since it has the ability to decrease the length of treatment.

REFERENCES

1. Kochar GD, Londhe SM, Varghese B, et al. Effect of low-level laser therapy on orthodontic tooth movement. J Indian Orthod Soc 2017;51:81–86. DOI: 10.10.4103/jios.jios_200_16

2. Yassaei S, Fekrazad R, Shahraki N. Effect of low level laser therapy on orthodontic tooth movement: a review article. J Dent (Tehran) 2013;10(3):264–272. PMID: 25512754.

3. Rai S, Ranjan V, Misra D, et al. Management of myofascial pain by therapeutic ultrasound and transcutaneous electrical nerve stimulation: a comparative study. Eur J Dent 2016;10(1):46–53. DOI: 10.4103/1305-7456.175680

4. Dalaie K, Hamedi R, Kharazifard MJ, et al. Effect of low-level laser therapy on orthodontic tooth movement: a clinical investigation. J Dent (Tehran) 2015;12(4):249–256. PMID: 26622279.

5. Wilcko WM, Wilcko T, Bouquot JE, et al. Rapid orthodontics with alveolar reshaping: two case reports of decrowding. Int J Periodontics Restorative Dent 2001;21(1):9–19. PMID: 11829041.

6. Yamasaki K, Miura F, Suda T. Prostaglandin as a mediator of bone resorption induced by experimental tooth movement in rats. J Dent Res 1980;59(10):1635–1642. DOI: 10.1177/00220345800590101301

7. Lim HM, Lew KK, Tay DK. A clinical investigation of the efficacy of low level laser therapy in reducing orthodontic postadjustment pain. Am J Orthod Dentofacial Orthop 1995;108(6):614–622. DOI: 10.1016/s0889-5406(95)70007-2

8. Chung H, Dai T, Sharma SK, et al. The nuts and bolts of low-level laser (light) therapy. Ann Biomed Eng 2012;40(2):516–533. DOI: 10.1007/s10439-011-0454-7

9. Wahl G, Bastänier S. Soft laser in postoperative care in dentoalveolar treatment. ZWR 1991;100(8):512–515. PMID: 1817386.

10. Anneroth G, Hall G, Ryden H, et al. The effect of low-energy infra-red laser radiation on wound healing in rats. Br J Oral Maxillofac Surg 1988;26(1):12–17. DOI: 10.1016/0266-4356(88)90144-1

11. Abergel RP, Lyons RF, Castel JC, et al. Biostimulation of wound healing by lasers: experimental approaches in animal models and in fibroblast cultures. J Dermatol Surg Oncol 1987;13(2):127–133. DOI: 10.1111/j.1524-4725.1987.tb00510.x

12. da Silva Sousa MV, Scanavini MA, Sannomiya EK, et al. Influence of low-level laser on the speed of orthodontic movement. Photomed Laser Surg 2011;29(3):191–196. DOI: 10.1089/pho.2009.2652

13. Rochkind S, Rousso M, Nissan M, et al. Systemic effects of low-power laser irradiation on the peripheral and central nervous system, cutaneous wounds, and burns. Lasers Surg Med 1989;9(2):174–182. DOI: 10.1002/lsm.1900090214

14. Karu TI. Molecular mechanism of the therapeutic effect of low-intensity laser radiation. Lasers Life Sci 1988;2:53–74. PMID: 3542462.

15. Kim YD, Kim SS, Kim SJ, et al. Low-level laser irradiation facilitates fibronectin and collagen type I turnover during tooth movement in rats. Lasers Med Sci 2010;25(1):25–31. DOI: 10.1007/s10103-008-0585-8

16. Bhad-Patil WA. Laser therapy for faster orthodontic tooth movement. APOS Trends Orthod 2014;4:111–115. DOI: 10.4103/2321-1407.139495

17. Aihara N, Yamaguchi M, Kasai K. Low-energy irradiation stimulates formation of osteoclast-like cells via RANK expression in vitro. Lasers Med Sci 2006;21(1):24–33. DOI: 10.1007/s10103-005-0368-4

18. Listgarten MA. Periodontal probing: what does it mean? J Clin Periodontol 1980;7(3):165–176. DOI: 10.1111/j.1600-051x.1980.tb01960.x

19. Habib FA, Gama SK, Ramalho LM, et al. Effect of laser phototherapy on the hyalinization following orthodontic tooth movement in rats. Photomed Laser Surg 2012;30(3):179–185. DOI: 10.1089/pho.2011.3085

20. Limpanichkul W, Godfrey K, Srisuk N, et al. Effects of low-level laser therapy on the rate of orthodontic tooth movement. Orthod Craniofac Res 2006;9(1):38–43. DOI: 10.1111/j.1601-6343.2006.00338.x

21. Youssef M, Ashkar S, Hamade E, et al. The effect of low-level laser therapy during orthodontic movement: a preliminary study. Lasers Med Sci 2008;23(1):27–33. DOI: 10.1007/s10103-007-0449-7

22. Wu JY, Chen CH, Yeh LY, et al. Low-power laser irradiation promotes the proliferation and osteogenic differentiation of human periodontal ligament cells via cyclic adenosine monophosphate. Int J Oral Sci 2013;5(2):85–91. DOI: 10.1038/ijos.2013.38

23. Doshi-Mehta G, Bhad-Patil WA. Efficacy of low-intensity laser therapy in reducing treatment time and orthodontic pain: a clinical investigation. Am J Orthod Dentofacial Orthop 2012;141(3):289–297. DOI: 10.1016/j.ajodo.2011.09.009

24. Hsu LF, Tsai MH, Shih AH, et al. 970 nm low-level laser affects bone metabolism in orthodontic tooth movement. J Photochem Photobiol 2018;186:41–50. DOI: 10.1016/j.jphotobiol.2018.05.011

25. Elkattan AE, Gheith M, Fayed MS, et al. Effects of different parameters of diode laser on acceleration of orthodontic tooth movement and its effect on relapse: an experimental animal study. Open Access Maced J Med Sci 2019;7(3):412–420. DOI: 10.3889/oamjms.2019.089

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