OBJECTIVE: This study aimed to evaluate the impact of simulated obesity in rats on Receptor Activator of Nuclear Factor κB (RANK), Receptor Activator of Nuclear Factor κB Ligand (RANKL) and Osteoprotegerin (OPG) expression during orthodontic tooth movement (OTM). METHODS: Forty male Wistar rats 6 weeks old were allocated into non-obese and obese groups. Obesity was simulated by a high-fat diet for 8 weeks. After, the left maxillary first molar was moved by stretched orthodontic nickel-titanium coiled springs. The animals were euthanized after 7 and 14 days of OTM, and the alveolar bone surrounding the roots of the left and right maxillary first molar was dissected to gene expression by qRT-PCR. TaqMan assays for RANK, RANKL, OPG and GAPDH were used, and the values of gene expression were compared by one- and two-way ANOVA with Tukey post-test (alpha = 5%). RESULTS: RANK expression in OTM side at 7 days was statistically different between non- and obese rats (p 0.05). The RANKL and OPG expression levels on the OTM side did not differ between the groups after 7 or 14 days of OTM. CONCLUSION: The RANKL and OPG gene expression is not affected by OTM in simulated obese rats. The impact of obesity on RANK gene expression needs to be further studied.
Monteiro et al. (2026) studied this question.