Abstract: Orthodontic tooth movement is the core treatment process in orthodontics. The metabolism of alveolar bone, which includes bone resorption on the pressure side and bone formation on the tension side, forms the basis of orthodontic tooth movement. Under the action of orthodontic force, the periodontal environment transforms into an inflammatory state, which disrupts the balance between bone formation and bone resorption in the alveolar bone, and excessive bone resorption becomes a challenging issue to control in orthodontic treatment. As an endogenous indole hormone, melatonin has been demonstrated to process a variety of physiological functions in recent years, such as regulating biorhythms, anti-inflammation, anti-oxidation, and immunomodulation. In the inflammatory microenvironment, melatonin can promote the osteogenic effects in bone metabolism through mechanisms such as osteoprotection, antioxidation, anti-inflammation, and the modulation of vascular function. Moreover, the key pathways by which melatonin exerts its regulatory effects in bone metabolism are similar to those related to alveolar bone metabolism during orthodontic tooth movement, suggesting that melatonin may play a crucial role in alveolar bone metabolism during the process of orthodontic tooth movement. In view of the positive role of melatonin in alveolar bone metabolism, this paper reviews the research progress of effect of melatonin on alveolar bone metabolism during orthodontic tooth movement.

Key words: melatonin, alveolar bone metabolism, orthodontic tooth movement, inflammatory environment