analysis of transforming growth factor- β1 gene expression in resorptive lacunae following orthodontic tooth movement: an animal survey

objective: : root resorption is a complication of orthodontic treatment and till date, there is a dearth of information regarding this subject. the aim of this study was to determine the relationship between orthodontic force and genetic expression of tgf-β(as an inflammatory cytokine) using the rt-pcr technique in rats. moreover, realization of the level of gene expression may help in the differential diagnosis of the disease, control and ultimate treatment. materials and methods: in this experimental study, a total of 24 eight-week old male wistar rats were selected randomly. on day 0, an orthodontic appliance, which consisted of a closed coil spring, was ligated to the upper right first molar and incisor. the upper left first molars in these animals were not placed under orthodontic force, to serve as the control group. on day 21, after anesthesia, the animals were sacrificed. the rats were divided into two equal groups: the first group was subjected to histological evaluation and the second group to rt-pcr measurements. orthodontic tooth movement was measured in both groups to determine the influence of the applied force. results: statistical analysis of data showed a significant (p<0.05) root resorption between the experimental group and control group, but there was no significant difference in the gene expression levels of inflammatory cytokine, that is tgf-β between the experimental and control groups. conclusion: : based on the finding of this study, it can be suggested that there is a direct relationship between orthodontic force and orthodontic induced inflammatory root resorption though no relationship exists between root resorption and inflammatory cytokine tgf-β gene expression in the resorptive lacunae.