摘要Over the past decade,dramatic progress has been made in dental research areas involving laser therapy.The photobiomodulatory effect of laser light regulates the behavior of periodontal tissues and promotes damaged tissues to heal faster.Additionally,photobiomodulation therapy(PBMT),a non-invasive treatment,when applied in orthodontics,contributes to alleviating pain and reducing inflammation induced by orthodontic forces,along with improving tissue healing processes.Moreover,PBMT is attracting more attention as a possible approach to prevent the incidence of orthodontically induced inflammatory root resorption(OIIRR)during orthodontic treatment(OT)due to its capacity to modulate inflammatory,apoptotic,and anti-antioxidant responses.However,a systematic review revealed that PBMT has only a moderate grade of evidence-based effectiveness during orthodontic tooth movement(OTM)in relation to OIIRR,casting doubt on its beneficial effects.In PBMT-assisted orthodontics,delivering sufficient energy to the tooth root to achieve optimal stimulation is challenging due to the exponential attenuation of light penetration in periodontal tissues.The penetration of light to the root surface is another crucial unknown factor.Both the penetration depth and distribution of light in periodontal tissues are unknown.Thus,advanced approaches specific to orthodontic application of PBMT need to be established to overcome these limitations.This review explores possibilities for improving the application and effectiveness of PBMT during OTM.The aim was to investigate the current evidence related to the underlying mechanisms of action of PBMT on various periodontal tissues and cells,with a special focus on immunomodulatory effects during OTM.