Orthodontic treatment involves the application of mechanical forces to teeth, inducing directed tooth movement through adaptive remodeling of the alveolar bone. This process is governed by mechanotransduction, where mechanical stimuli are converted into biochemical signals that orchestrate cellular responses. This narrative review synthesizes recent findings from peer-reviewed literature published between 2020 and 2025 on the biology of alveolar bone under orthodontic loading. Key topics include the anatomy and physiology of alveolar bone, principles of orthodontic force application, mechanisms of mechanotransduction, and the roles of key cells such as osteocytes, osteoblasts, and osteoclasts in bone remodeling. Signaling pathways like RANKL/OPG, Wnt/β-catenin, and cytokine networks are examined, highlighting their contributions to tension- and compression-side responses. Factors influencing these processes, including age-related changes, inflammation, and neural regulation, are also discussed. The review underscores the importance of understanding these mechanisms to optimize orthodontic outcomes, minimize adverse effects like root resorption, and explore novel therapeutic interventions such as photobiomodulation or targeted molecular modulation. By integrating cellular, molecular, and biomechanical perspectives, this article provides a comprehensive framework for advancing orthodontic research and clinical practice.
