Molecular Signatures of Orthodontic Tooth Movement: A Narrative Review

Orthodontic Tooth Movement (OTM) is a biologically regulated process initiated by mechanical forces that trigger coordinated inflammatory and bone remodelling responses within the Periodontal Ligament (PDL) and alveolar bone. Current evidence on biomarkers involved in OTM is fragmented, necessitating a comprehensive synthesis of their biological significance and clinical relevance. Accordingly, the present review critically evaluates existing evidence on biomarkers associated with OTM, examines methodological considerations in their detection and explores their clinical applicability in orthodontic practice. Numerous biomarkers including cytokines, prostaglandins, Matrix Metalloproteinases (MMP), Receptor Activator of Nuclear Factor κB Ligand/ Osteoprotegerin (RANKL/OPG) signalling components, Alkaline Phosphatase (ALP), osteocalcin and Nitric Oxide (NO) have been investigated to better understand and monitor these events. Gingival Crevicular Fluid (GCF) owing to its proximity to local tissue changes and higher mediator concentrations, represents the most promising medium for orthodontic biomarker assessment, while saliva offers additional potential for genetic and host response analysis. Biomarker fluctuations correlate with force magnitude, remodelling intensity and the rate of tooth movement during orthodontic treatment. However, translation of these findings into routine clinical practice remains limited by the absence of standardised protocols and the influence of multiple biological and mechanical factors. With advances in multiplex, proteomic and vesicle-based analytical technologies, validated biomarker panels may facilitate biologically guided, personalised orthodontic care in the future.