Photobiomodulation and orthodontic root resorption: A systematic review and meta-analysis

Area of Science:

• Orthodontics
• Biotechnology
• Regenerative Medicine

Background:

• Orthodontically induced inflammatory root resorption (OIIRR) is a common complication of orthodontic treatment.
• Photobiomodulation (PBM) is an emerging non-invasive therapy with potential to mitigate OIIRR.

Purpose of the Study:

• To systematically review and meta-analyze randomized controlled trials (RCTs) evaluating the efficacy of PBM in reducing OIIRR in human orthodontic patients.
• To identify optimal PBM parameters for managing root resorption during orthodontic therapy.

Main Methods:

• A comprehensive systematic search was performed across major databases up to January 2025.
• Eight RCTs involving 185 participants were included, with risk of bias assessed using the Cochrane RoB 2 tool.
• Meta-analysis and subgroup analyses were conducted using RevMan 5.4 to evaluate treatment effects and heterogeneity.

Main Results:

• LED interventions demonstrated a statistically significant reduction in root resorption (MD = -0.15).
• LLLT showed a trend towards reduced resorption, but results were not statistically significant (SMD = -1.69).
• Significant root resorption reduction was observed specifically in canine teeth (MD = -0.49). Beneficial effects were associated with specific parameters: ≥850 nm wavelength, >10 J/cm² fluence, <25 mW/cm² irradiance, >2 min duration, and >6 sessions.

Conclusions:

• PBM shows promise in managing OIIRR, particularly with LED interventions.
• The current evidence base is limited by the small number of studies and significant heterogeneity.
• Further high-quality RCTs with robust designs and longer follow-up periods are necessary to validate these exploratory findings.