Effect of cyclosporine-A on orthodontic tooth movement in rats.

OBJECTIVE: The objective of this study is to examine the effect of cyclosporine-A (CsA) on the rate of orthodontic tooth movement in rats. SETTING AND SAMPLE POPULATION: This is a randomized controlled trial with a split-mouth design in Sprague-Dawley rats. MATERIAL AND METHODS: Eighteen rats, divided at random in two groups, were fed with 8 mg/kg CsA (experiment) or mineral oil (control) daily after initial healing of bilateral maxillary second molar removal. All rats received orthodontic coil springs (10 cN) secured to the maxillary incisors and first molars at the rights side, while no springs were placed at the left. Distances between first and third molars were measured on days 0, 3, 6, and 12. After sacrificing on day 12, the alveolar ridges of the maxillae were sectioned and blood samples were collected for serum tartrate-resistant acid phosphatase (TRAP)-5b level detection and for histology, respectively. RESULTS: Significantly larger changes in intermolar distances were found after orthodontic force application in the CsA group at days 3 and 12 when compared with the control group. The inter-radicular dental alveolus of CSA-fed rats was osteopenic. Significantly increased TRAP-5b serum level was noted in the CsA group when compared with the control group. CONCLUSIONS: We suggest that CsA enhanced the rate of orthodontic tooth movement. The osteopenia and the increased osteoclastic activity could be the underlying factors.