The Effectiveness of Physical Adjunctive Interventions in the Acceleration of Orthodontic Tooth Movement: An Umbrella...

Orthodontic treatment often lasts around 20 months, and prolonged duration increases the risk of adverse events. Physical adjunctive interventions (PAIs) are proposed to accelerate tooth movement, but their efficacy remains uncertain. This umbrella review synthesized systematic reviews and meta-analyses of randomized clinical trials (RCTs) on PAIs published through March 2025 (PubMed, Web of Science, Scopus, Cochrane Library). Review quality was appraised with the A Measurement Tool to Assess Systematic Reviews-2 (AMSTAR-2) and the Risk of Bias in Systematic Reviews (ROBIS) tools. Study overlap was quantified using the corrected Graphical Representation of Overlap for Overviews (GROOVE) method. Risk of bias in the primary studies was reassessed, when required, using the Cochrane Risk of Bias 2 (RoB 2) tool. Certainty of evidence was rated with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Random-effects models were used when statistical heterogeneity was substantial (I ² > 50%); otherwise, fixed-effects models were used. Effect estimates are reported as mean difference (MD) with 95% confidence intervals (CIs). Seventeen systematic reviews (12 meta-analyses, 5 narrative) covering 76 RCTs were included. Vibration devices showed minimal or no clinically significant acceleration: leveling/alignment MD = 0.05 mm (95% CI: -0.38 to 0.49), canine retraction + 0.27 mm/month (95% CI: 0.19-0.35), en-masse retraction + 0.19 mm/month (95% CI: -0.25 to 0.63) (GRADE: moderate-very low). Low-level laser therapy (LLLT) shortened alignment by -58.4 days (95% CI: -88.6 to -28.2) and, in maxillary extraction, by -28 days (95% CI: -39 to -17), with early canine retraction gains (95% CI: +0.31 to +0.27 mm/month) (GRADE: moderate-very low). Light-emitting diode (LED) therapy showed + 0.005 mm/day (95% CI: -0.001 to 0.012) with small, non-significant monthly estimates (GRADE: low-very low). Bioelectric stimulation (BES) added + 1.78 mm at 3 months (95% CI: 0.99-2.57) (GRADE: low). Overall, methodological quality varied widely, with most reviews rated low to critically low by AMSTAR-2 and at high risk of bias by ROBIS. Vibration should not be the primary accelerator. Photobiomodulation (PBM) is the most promising clinical option, but it requires standardized protocols (wavelength, dose, schedule). BES is promising yet underpowered. Registration: PROSPERO CRD420251043659.