The Impact of Atorvastatin on RANKL Expression in Rats during the Retention Stage after Orthodontic Tooth Movement

OBJECTIVE: To probe into the impact of atorvastatin on RANKL expression in rats during the retention stage after orthodontic tooth movement and its associated molecular mechanisms. METHODS: After establishing an orthodontic tooth movement model, the left teeth of the retention-stage rats were the maintained side, and the right teeth were the nonmaintained side, which were given physiological saline or atorvastatin dosing at 7d, 14d, and 21d, respectively, by tube feeding, in order to keep the rats as a control group at the beginning of the retention stage. A model of the rat's upper jaw gypsum in each group was made at various time points to measure the distance at which the teeth relapsed. The pathological slices of the upper jaw arch were taken separately for TRAP staining observation. RESULTS: Compared to the physiological saline group, the recurrence distance of rats in the atorvastatin group was visually lower (p < 0.05), and the number of bone-breaking cells was signally lower (p < 0.05); P-5b, PTH, VitD3, GC, IL-1, and IL-17 expressions (p < 0.05) were visually decreased, while IL-11 expression was elevated (p < 0.05). CONCLUSION: The atorvastatin given to rats during the retention stage after orthodontic tooth movement inhibits RANKL expression and may function through OPG/RANKL/RANK system.