ASSOCIATION OF VITAMIN D RECEPTOR GENE POLYMORPHISM WITH EXTERNAL APICAL ROOT RESORPTION IN ORTHODONTICALLY TREATED PATIENTS

Abstract

The vitamin D receptor influences host immune responses and aspects of bone development, growth, and homeostasis. The aim of this study was to investigate the association of the polymorphism of the vitamin D receptor gene TaqI with external apical root resorption during orthodontic treatment. Methods: Our sample consisted of 50 patients aged between 12 and 40 years, who received fixed total orthodontic treatment during the years 1999 and 2000. External apical root resorption (RAAR) of the maxillary incisors was evaluated on periapical radiographs taken before and after 6 months of treatment. After DNA collection and purification, the analysis of the TaqI polymorphism of the vitamin D receptor was performed by polymerase chain reaction followed by restriction fragment length polymorphism. Univariate and multivariate analyses were performed to verify the association of clinical and genetic variables with external apical root resorption (P<0.05). There was a correlation between the VDR and RRAE variables (r= 0.306 and p= 0.030). The genotype resulting from Taq1 cleavage and allele frequencies differed between the groups with and without RAAR. Individuals containing the T allele were more likely to develop RAAR when compared to individuals carrying the tt genotype (OR= 7.5; 95% CI= 1.8 – 31.4; p= 0.0094). The TaqI polymorphism of the vitamin D receptor gene was associated with external apical root resorption in orthodontically treated patients.