Retention after orthodontic treatment relies on continuous alveolar bone remodeling to preserve stability. Pulsed electromagnetic field (PEMF) stimulation, widely used in managing bone disorders, may support this process by promoting osteogenesis and limiting resorption. In this study, 36 male Wistar rats were assigned to control, PEMF 7-day, and PEMF 14-day groups. Tooth movement was first induced with nickel–titanium coil springs for 21 days, after which retention was simulated by filling the created space with glass ionomer cement. During retention, experimental groups were exposed daily to PEMF (15 Hz, 2.0 mT, 2 h). Animals were sacrificed at different time points to measure Wnt5a mRNA and the protein levels of RANKL, OPG, ALP, and Runx2 on the tension side. Statistical analysis (ANOVA, p < 0.05) revealed that PEMF exposure elevated Wnt5a, OPG, ALP, and Runx2 expression, while suppressing RANKL compared with controls. These findings indicate that PEMF facilitates alveolar bone remodeling during orthodontic retention by enhancing bone formation and reducing bone resorption.
