Objective: This meta-analysis evaluated the effectiveness of photobiomodulation therapy (PBMT) on accelerating orthodontic tooth movement (OTM) in clinical practice. Methods: Data from bilingual journals across seven different databases were compiled and analyzed. Randomized controlled trials (RCTs) and quasi-RCTs regarding the effect of PBMT on OTM in cases with four first premolar extractions in split-mouth design were selected. This study was conducted after approval from the IRB. The outcome variables were the cumulative tooth movement distances in 1, 2, and 3 months. Data extraction was performed by two authors independently and in duplicate. Risk of bias was assessed. Results: Eight RCTs and one quasi-RCT were ultimately included and analyzed in meta-analysis. This study revealed that the pooled mean difference (MD) among these trials was 0.30 [95% confidence interval (CI): -0.02 to 0.62], 0.69 (95% CI: 0.08 to 1.29), and 0.64 (95% CI: -0.01 to 1.29) for 1, 2, and 3 months, respectively. The results remained consistent after sensitivity analysis assessment. Conclusions: There is insufficient evidence to support that photobiomodulation accelerates tooth movement in orthodontic treatments. Our results suggest that the optimal parameters of PBMT on OTM in human might be about 20 mW, 5-8 J/cm2, 0.5 W/cm2, 0.2 J/point, and 2-10 J/tooth. More large-sample multicenter clinical trials carried out in similar settings are required to confirm and pinpoint treatment efficiency and optimal parameters. Registration: The review protocol was not registered prior to the study.
Keywords: laser parameters; meta-analysis; orthodontic tooth movement; photobiomodulation.