Background : Photobiomodulation (PBM), previously referred to as low-level laser therapy (LLLT), has developed into a non-invasive and biologically based complement in orthodontic practice. Utilising low-intensity light within the red to near-infrared spectrum, PBM has shown potential in expediting orthodontic tooth movement, alleviating treatment-related discomfort, and promoting tissue repair. Objective: This review aims to comprehensively analyze current human and experimental evidence regarding the efficacy, mechanisms, parameters, and clinical applications of PBM in orthodontics, while highlighting its advantages, limitations, and future prospects. Methods : A systematic literature search was conducted using PubMed, Scopus, and Google Scholar databases for studies published up to 2025. Clinical trials, in vitro and in vivo studies, and systematic reviews investigating PBM for orthodontic purposes were included. Key variables such as wavelength, energy density, application mode, and biological outcomes were extracted and compared. Results : Numerous clinical and preclinical studies report that PBM accelerates orthodontic tooth movement by modulating mitochondrial function, increasing cytokine activity (e.g., IL-1β, RANKL), and enhancing bone remodeling. Wavelengths between 630 and 940 nm have shown efficacy. While lasers and LEDs are used, intraoral LED devices offer greater practicality for daily use. Pain reduction and soft tissue healing benefits have also been consistently reported. However, inconsistencies in PBM parameters, treatment intervals, and study designs limit direct comparability and standardization. Conclusion : Photobiomodulation represents a promising adjunctive tool in orthodontics, capable of enhancing treatment efficiency and patient comfort. Despite encouraging outcomes, standardized protocols and long-term multicenter trials are needed to fully establish its clinical utility and optimize therapeutic parameters.