Effect of isotretinoin on induced tooth movement in rats.

INTRODUCTION

This study was performed to evaluate the effect of isotretinoin on tooth displacement and tissues related to induced tooth movement (ITM) in rats.

METHODS

Wistar rats were randomly divided into 4 groups: vegetable oil (O; n = 40), 7.5 mg/kg isotretinoin (I; n = 40), vegetable oil + ITM (OM; n = 44), and 7.5 mg/kg isotretinoin and ITM (IM; n = 39). After the daily application of the solutions for 30 days, an orthodontic appliance was installed to mesially displace the maxillary first right molar (30 cN) of rats in the OM and IM groups. The animals were killed 2, 7, 14, or 21 days after placement of the devices. The animals in the O and I groups did not undergo ITM but were killed simultaneously. The animals were examined for tooth displacement, the neoformation of mature collagen, bone and root resorption, the presence of hyalinized areas, and trabecular bone modeling by microcomputed tomography.

RESULTS

There was no difference in tooth displacement, the number of osteoclasts, the presence of hyalinized areas, or trabecular bone among the O, I, OM, and IM groups across the periods tested (P >0.05). A lower percentage of mature collagen was found in the IM group than in the OM group on day 7 (P <0.05). A lower frequency of root resorption was found in the IM group than in the OM group on days 2 and 21 (P <0.05).

CONCLUSIONS

Isotretinoin at 7.5 mg/kg decreased root resorption in rats subjected to ITM.