The effect of tooth loss on endocrine profile: changes in G-protein-coupled estrogen receptor, oxytocin receptor, and steroid hormone levels

Purpose: This study aims to simultaneously evaluate serum G Protein-Coupled Estrogen Receptor (GPER) and Oxytocin Receptor (OXTR) levels alongside steroid hormone profiles in relation to tooth loss severity.Materials and Methods: 57 volunteers (28 female, 29 male; aged 28–54) were stratified by missing teeth: Group 1 (0–3, n=31), Group 2 (4–8, n=15), Group 3 (11–28, n=11). Serum GPER and OXTR were measured by Enzyme-Linked Immunosorbent Assay (ELISA), and steroid hormones by an automated analyzer. Results: Estradiol (E2), progesterone (prog), and GPER declined significantly with increasing tooth loss, with GPER confirmed as an independent predictor by generalized linear models (GLM). In females, OXTR also differed significantly among groups, with OXTR and GPER emerging as independent predictors. ROC analysis results demonstrated strong diagnostic performance for prog [Area Under Curve (AUC)=1.0] and OXTR (AUC=0.869) in the female cohort. Conclusion: This study provides the first evidence that GPER and OXTR levels are associated with tooth loss severity. These findings suggest that declining steroid hormones and their receptors may contribute to impaired alveolar bone homeostasis through sex-specific mechanisms, which may have implications for prosthodontic treatment planning, pending validation with clinical outcome data.