Umbrella review of photobiomodulation/low-level laser therapy and vitamin D in orthodontics: effects on tooth movement, pain, root resorption, and bone biomarkers

To synthesize evidence from systematic reviews and meta-analyses on low-level laser therapy/Photobiomodulation (LLLT/PBM) and vitamin D as non-invasive adjuncts for accelerating orthodontic tooth movement (OTM) and mitigating associated side effects. PubMed/MEDLINE, Embase, Scopus, Web of Science, and Cochrane Library databases were searched from inception to November 18, 2025. SRMAs primarily comprising human RCTs evaluating LLLT/PBM or vitamin D in orthodontics were included; in some mixed-design reviews, clearly separable human orthodontic data from a small number of CCTs were retained narratively. (one pre-registered exception with 4 RCTs for vitamin D to ensure completeness). Randomized controlled trials were prioritized; some retained reviews also included a small number of controlled clinical trials when relevant human orthodontic data were clearly separable. Quality was assessed using AMSTAR-2, ROBIS, and GRADE. Narrative synthesis was performed because of high heterogeneity. Twenty systematic reviews and meta-analyses covering a large number of human orthodontic trials were included. Low-certainty evidence suggests that LLLT/PBM may be associated with accelerated OTM, slight reductions in orthodontically induced inflammatory root resorption (OIIRR), and short-term pain relief. Vitamin D showed inconsistent findings across outcomes with no reliable overall clinical benefit. Current evidence is insufficient to recommend the routine clinical use of LLLT/PBM or vitamin D in orthodontics. PROSPERO CRD42024591253. Orthodontic treatment often involves long treatment durations, potentially causing discomfort, root damage, and reduced compliance. This review examines evidence from systematic reviews and meta-analyses on low-level laser therapy/photobiomodulation (LLLT/PBM) and vitamin D as possible aids for faster tooth movement through bone remodeling. Low-certainty evidence suggests that LLLT/PBM may be associated with slightly faster tooth movement, minor reductions in root resorption, and pain relief. However, the high variability among studies reduces confidence in these suggestions. Vitamin D showed no consistent association with accelerated OTM or other outcomes (very low certainty evidence); exploratory subgroup findings on local administration were inconsistent and insufficient for recommendations. Overall, inconsistencies limit reliable conclusions and highlight the need for better-designed trials to provide clearer guidance on this topic.