Association of functional gene polymorphism IL-1beta in patients with external apical root resorption.

Introduction: External apical root resorption (EARR) is a frequent complication of orthodontic treatment. Interleukin 1beta (IL-1beta) is a potent stimulus for bone resorption and osteoclastic cell recruitment during orthodontic tooth movement. The purpose of this study was to assess the association between a polymorphism in the IL-1beta genes and EARR during orthodontic treatment.

Methods: The sample included 61 Brazilian orthodontic patients, divided into 2 groups according to the presence (affected group, n = 23) or absence (control group, n = 38) of EARR in the central and lateral maxillary incisors in the posttreatment period. DNA was obtained from buccal swab cells. The polymorphism was analyzed by the polymerase chain reaction followed by digestion with restriction enzyme. The polymerase chain reaction products were analyzed in 10% polyacrylamide gel and stained with silver.

Results: There were significant statistical differences (P <0.05) among the frequencies of the alleles and genotypes of the IL-1beta gene polymorphism between the affected and unaffected groups, suggesting that allele 1 predisposed the subjects to EARR (odds ratio = 4.0).

Conclusions: The polymorphism of the IL-1beta gene is associated with root resorption in the studied population.