ABSTRACT
Immunosuppressive drugs have special effects on bone remodeling during orthodontic tooth movement. This study aimed at investigating the effect of oral Cyclosporin A, an immunosuppressive drug, on the orthodontic tooth movement in rats. Eighty male Sprague-Dawley rats, weighting 220-280 gm, were used. The animals were randomly assigned into control and experimental groups, each one containing 40 rats. Each group included four subgroups, each of 10 rats. Four groups of rats were selected for the assessment of the effect of olive oil and stripping stress of the lower incisors for a period of 15 and 30 days. The two experimental sub-groups received 10 mg/kg Cyclosporine A by gastric gavages every 24 hours for 15 and 30 days. The other two experimental sub-groups received 30 mg/kg cyclosporine-A by gastric gavages every 24 hours for 15 and 30 days. A fixed orthodontic appliance consisting of nickel - titanium closed coil spring, was ligated between the maxillary right incisor and the first molar. The initial activating force was 60 gm. One way Analysis of Variance and Tukey were used for comparing tooth movement between the two groups and eight sub-groups. The results showed that oral Cyclosporine A [30 mg/kg/30 day] could accelerate the rate of orthodontic tooth movement in rat [0.635 +/- 0.22 mm] [P<0.05]. Also, its administration period was more effective than the dose itself. Olive oil and stripping stress could not increase the rate of tooth movement. Due to the findings of this study and predominant effect of Cyclosporine A on orthodontic tooth movement in rats, the patients using Cyclosporine A may have the chance of more tooth movement. Further studies are requested for evaluating the effect of Cyclosporine A on increasing tooth movement in accordance with its dose and duration