Is photobiomodulation effective during maxillary expansion? A systematic review and meta‐analysis

We performed a systematic review on literature associated with meta‐analyses to elucidate whether (I) low‐level laser therapy (C) compared to placebo accelerates (O) bone neoformation in the region of the midpalatal suture in (P) patients undergoing transverse maxillary expansion. Two reviewers blindly performed targeted searches using the selection criteria (PICOS) in seven major databases and three grey literature databases, employing specific terms and their entrenchments. The RevMan® software (Review Manager, version 5.3, Cochrane Collaboration) was used to adapt the RoB summary illustration to the Cochrane 2.0 tool questions. Meta‐analysis was performed using standardized mean difference (SMD) and Cohen's d calculation on random effects, tests for heterogeneity (I2) and publication bias (Egger and Begg), and one‐of‐out sensitivity analysis. GRADE (Grading of Recommendations Assessment, Development and Evaluation) was used for evidence quality analysis. Among the five studies included in the qualitative synthesis, three were included in the meta‐analysis. All analysed studies were prospective randomized clinical trials. The risk of bias was such that the Egger (P = .1991) and Begg (P = .024) tests showed no significant risk of publication bias. The meta‐analysis showed high heterogeneity (I2 = 81%, P