Influence of photobiomodulation on pain perception during initial orthodontic tooth movement

The effectiveness of low-level laser therapy and low-intensity pulsed ultrasound in reducing pain induced by orthodontic separation: a randomized controlled trial

BACKGROUND

The low-level laser therapy (LLLT) and low-intensity pulsed ultrasound (LIPUS) have been recently applied to control pain during orthodontic treatment.

OBJECTIVE

To evaluate and compare the effectiveness of LLLT and LIPUS in reducing pain induced by orthodontic separation.

STUDY DESIGN

A single-blinded randomized controlled trial.

METHODS

One hundred and fifty patients were randomly assigned into three groups; LLLT group, LIPUS group, and control group. After 5 min from the separators' placement, the first dose of the laser or the ultrasound was applied, the second dose was applied after 24 h, and the third dose was applied after 48 h on both maxillary and mandibular first molars. The exposure of laser was for 20 s at each point (maxillary and mandibular first molars), with an 810-nm aluminum-gallium-arsenide (AlGaAs) diode laser on continuous mode. The output power set at 150 mW, the energy density of 4 J/cm2, and a laser spot diameter of 7 mm were applied. Whereas the frequency of ultrasonic toothbrush was 1.6 MHz; and average output intensity was 0.2 W/cm2. The application was for 20 min (5 min on each first molar). The control group received the separators without another intervention. A Visual Analog Scale (VAS 100 mm) was used to assess pain intensity at several time intervals during the first four days after the separators' placement.

RESULTS

A total of 145 patients were assessed. There was a significant difference in pain perception among the three groups after 5 min (P = .002). The maximum pain level was reached after 24 h. However, the laser group and the ultrasound group showed a statistically significant decrease in pain scores compared to the control group at all the assessment time points (P < .001). Whereas there was no difference between the laser group and the ultrasound group in reducing the pain scores (P > .05).

CONCLUSIONS

The LLLT and the LIPUS effectively reduce the separation pain when applied in multiple doses without differences between them.

TRIAL REGISTRATION

This trial was registered with the German Clinical Trials Register (DRKS). ( https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID= DRKS00029991). Date of registration: 26/08/2022.

The effectiveness of interventions in reducing pain related to orthodontic separation: a systematic review and meta-analysis

BACKGROUND

Pain is an unpleasant experience and annoying sensation. To control this pain during orthodontic separation, different pharmacological and non-pharmacological methods have been used.

OBJECTIVE

This systematic review and meta-analysis aimed to critically assess the evidence of the effectiveness of pharmacological and non-pharmacological methods in reducing pain induced by orthodontic separation.

SEARCH STRATEGY

An electronic search was conducted using the following databases: PubMed® (Medline), Scopus®, EMBASE®, Web of ScienceTM, Google ScholarTM, ProQuest, and Cochrane Central Register of controlled trials (CENTRAL) searching for the studies published between January 2012 and April 2023.

SELECTION CRITERIA

Only randomized controlled trials (RCTs) were included, each experimental group included patients who received elastomeric separators and one kind of pharmacological or non-pharmacological interventions for pain reduction during the separation stage.

DATA COLLECTION AND ANALYSIS

Cochrane's risk of bias tool (RoB2 tool) was applied. The Grading of Recommendations Assessment, Development, and Evaluation [GRADE] approach was used to evaluate the strength of the evidence.

RESULTS

Thirty-one studies (RCTs) were included in this systematic review. Nineteen of them were appropriate for quantitative synthesis and used VAS for pain assessment. Meta-analysis showed that low-level laser therapy (LLLT) was an effective approach for pain relief after separators placement with standard mean difference of 13.79 mm (95% confidence interval (CI): -15.64, -11.94) at 6 h and 23.34 mm at 24 h (95% CI: -25.91, -20.77). LLLT was also effective when applied in split-mouth and the standard mean difference was 8.9 mm at 6 h (95% CI: -12.86, -3.33) and 17.15 mm at 24 h (95% CI: -30.12, -4.17). Ibuprofen had a pain control effect at 6 h and at 24 h compared with the placebo group. The standard mean difference was 14.37 mm (95% CI: -20.54, -8.19) and 20.46 mm (95% CI: -27.79, -13.13), respectively. There was no difference in pain control between ibuprofen and acetaminophen. Naproxen had lower visual analog scale scores in pain perception at 6 h and the standard mean difference was 7.03 mm (95% CI: -12.67, -1.40).

CONCLUSIONS

The application of LLLT decreased the pain induced by the separation during the first day of teeth separation; the pain reduction showed an increase from 6 h to the end of the 24 h. However, the evidence is weak to moderate. The analgesics reduced the pain compared to placebo; this pain reduction had shown an increase from 6 h to the end of the 24 h. The strength of the evidence is moderate. Naproxen gel effectively reduced the pain compared to placebo; the evidence in this regard is moderate. Naproxen gel effectively reduced the pain compared to placebo, but it was less effective than the oral intake of non-steroidal anti-inflammatory drugs. However, the evidence in this regard is moderate.

REGISTRATION

This systematic review was registered with PROSPERO (CRD42022335553) during the first stages of its conduction.

The Optimal Energy Density of Photobiomodulation Therapy in Decreasing Orthodontic-Related Pain: A Systematic Review and Network Meta-Analysis

Objective: The aim of this network meta-analysis (NMA) was to explore the optimal energy density (ED) for relief of orthodontic-related pain by photobiomodulation therapy. Background: Orthodontic treatment corrects the deformity of teeth, dental arch, jaw, and face using various orthodontic devices under the action of biomechanics. Materials and methods: A computerized literature search was conducted within the MEDLINE, EMBASE, Scopus, Cochrane Library, Web of Science, CNKI, Wanfang, VIP, and CBM databases to identify randomized controlled trials (RCTs) that used photobiomodulation therapy to relieve pain during orthodontic treatment. Particular inclusion and exclusion criteria were connected to recognize relevant articles. The information was extricated autonomously by two reviewers, and a quality assessment was carried out by utilizing the Cochrane Collaboration "risk of bias" tool. The RevMan 5.4 software and STATA 15.0 were utilized for data analysis. Also, the NMA was performed with mvmeta commands in Stata (StataCorp, TX). Results: Of the 1024 recognized articles, 21 RCTs were at long last included. Within the risk-of-bias assessments, 2 studies displayed a high risk, 17 an unclear risk, and 2 a low risk. The global and local inconsistency of the NMA in 1 and 2 days was not significant; however, the NMA in 3 days showed a significant inconsistency. Laser with lower ED (0-10 J/cm²) appeared to be the most noteworthy possibility to become the optimal intervention, and it also had the highest mean rank in the rankogram and the biggest value of surface under the cumulative ranking in all three NMA structures. Conclusions: On account of the limited evidence of included trials, laser with lower ED (0-10 J/cm²) appeared to be more valid than the remaining treatment modalities (laser with higher ED, placebo, and control) for pain reduction in 1, 2, and 3 days after orthodontic procedures were applied. In the future, more high-quality research with consistency in research design is needed for further evaluation.