The Impact of Systemic Simvastatin on Bone Remodeling Following Rapid Maxillary Expansion: An In Vivo Study

Abstract

A midpalatal suture contention after rapid maxillary expansion (RME) is a major orthodontic challenge. The objective of this study is to evaluate the effect of systemic simvastatin on suture bone remodeling after disjunction. For that, 15 Wistar rats were used. In 10, orthodontic appliances were installed and activated for 5 days for RME. These animals were randomly divided into two groups: control (CT, n = 5) and simvastatin (SVT, n = 5). Also, animals without intervention (HG, n = 5) were used. In the SVT and CT groups, 5 mg/kg of simvastatin and distilled water were administered by gavage, respectively, for 20 consecutive days. Then, the animals were euthanized and scanned in micro-computed tomography (µCT). The images were analyzed through pixel linear measurement at four different points (P1, P2, P3 and P4), in the intra-incisor distance (DI) and in the suture distance (SD). Microtomographic parameters, such as cortical bone area (Ct.Ar), cortical area fraction (Ct.Ar/Tt.Ar), and cortical thickness (Ct.Th), were obtained. Also, bone volume fraction (BV/TV) and empty space (EV) were extracted. Then, histological slides were prepared for descriptive and histomorphometric analysis. There was a statistically significant difference in the linear measurements, microtomographic parameters, and histomorphometric results between the experimental groups. In conclusion, simvastatin demonstrated an osteoinductive and antiresorptive effect in the palatine suture region after RME.

Keywords

• simvastatin
• rapid maxillary expansion
• micro-computed tomography
• rats
• histomorphometry