The Effect of Statins on Orthodontic Tooth Movements: A Meta-analysis of Animal Studies

Background: Statins are effective therapeutic agents for the treatment of cardiovascular diseases. Their favorable effects on various aspects of oral health including promising effects on bone metabolism and pleiotropic impacts such as anti-inflammatory properties made these drugs a current area of interest in the field of orthodontics. Therefore, the aim of this study was to evaluate the effects of statins on orthodontic tooth movement (OTM) in animals undergoing orthodontic treatments. Methods: Several databases were comprehensively searched for studies measuring the effects of statins on the OTM up to January 2020, including MEDLINE, ISI Web of Science, EMBASE, Scopus, and Cochrane. Animal studies evaluating the effects of statins on tooth movements in animals undergoing orthodontic treatments were selected based on the PICO model .Study selection, data extraction, risk of bias, and study quality assessment were independently performed by two reviewers. Finally, the data were analyzed using random-effects meta-analysis and the mean difference (MD) was used for comparing the outcome measures. Results: Three randomized trials were finally included in this meta-analysis. According to the Systematic Review Centre for Laboratory animal Experimentation Tool, all the included studies had at least one domain at a high risk of bias. The amount of the OTM was insignificantly lower in the statin group (MD = 0.134 mm, %95 confidence interval = -0.020-0.288, P>0.05). Conclusions: Due to the low quality and methodological inconsistencies among the included studies, conclusive confirmation regarding the effect of statins on the OTM remains debatable. Trail Registration: The protocol of this study was registered on PROSPERO (https://www.crd.york.ac.uk/ PROSPERO/) with the ID # CRD42020164155.