Iglesias-Linares A, Yañez-Vico R M, Moreno-Fernández A M, Mendoza-Mendoza A, Orce-Romero A, Solano-Reina E
Department of Orthodontics, School of Dentistry, University of Seville, Seville, Spain.
Oral Dis. 2014 Apr;20(3):307-12. doi: 10.1111/odi.12114. Epub 2013 Apr 25.
External apical root resorption (EARR) is a frequent iatrogenic effect of orthodontic treatment. Substantial variability in responses to postorthodontic EARR has been observed among patients even when similar treatment protocols were used. This observation suggests that environmental and/or genetic variations between individuals may confer susceptibility or resistance to developing EARR. The objective of this study is to determine whether variants in the osteopontin gene, an essential mediator in the odontoclast fusion and attachment process, are positively/negatively associated with postorthodontic EARR.
Genetic screening of eighty-seven orthodontic patients was performed for two polymorphisms in the osteopontin gene cluster (rs9138 and rs11730582). Subjects were divided into groups, according to the presence or absence of EARR (>2 mm). Genotype distributions and allelic frequencies were calculated using the chi-square test. Logistic regression analysis was used to assess the extent to which clinical-related parameters interfered with the EARR. Odds ratios (OR) and 95% confidence intervals were also calculated.
Data from this study show that subjects heterozygous and homozygous for the most frequent allele of the osteopontin gene at position 89261521 [OR: 0.035 (P = 0.035*) (allele A)] and 89253600 [OR: 0.20 (P = 0.025*) (allele T)], respectively, are protected against postorthodontic EARR. Nevertheless, a highly significant association was found in the comparative analysis of homozygous subjects [2/2 (CC)] for the osteopontin gene (rs9138), resulting in an increased risk of suffering postorthodontic EARR[OR: 4.10; P = 0.045*; CI: 95%]. Subjects who were homozygous [2/2 (CC)] for the osteopontin gene (rs11730582) were more likely, and to a greater extent, to be affected with EARR [OR: 11.68; P < 0.039*; CI: 95%] compared with other genotypes.
Variations in the osteopontin gene (rs9138 and rs11730582) are determinants of a genetic predisposition to suffer EARR secondary to orthodontic treatment.
根尖外吸收（EARR）是正畸治疗常见的医源性效应。即使采用相似的治疗方案，患者正畸后EARR的反应仍存在显著差异。这一现象表明个体间的环境和/或基因差异可能导致EARR发生的易感性或抗性。本研究的目的是确定骨桥蛋白基因的变异（破骨细胞融合和附着过程中的重要介质）是否与正畸后EARR呈正/负相关。
对87例正畸患者进行骨桥蛋白基因簇中两个多态性位点（rs9138和rs11730582）的基因筛查。根据是否存在EARR（>2mm）将受试者分组。采用卡方检验计算基因型分布和等位基因频率。使用逻辑回归分析评估临床相关参数对EARR的干扰程度。还计算了比值比（OR）和95%置信区间。
本研究数据显示，骨桥蛋白基因在位置89261521 [OR: 0.035 (P = 0.035*) (等位基因A)] 和89253600 [OR: 0.20 (P = 0.025*) (等位基因T)] 处最常见等位基因的杂合子和纯合子受试者分别对正畸后EARR具有抗性。然而，在骨桥蛋白基因（rs9138）纯合子受试者[2/2 (CC)]的比较分析中发现高度显著的关联，导致正畸后EARR风险增加[OR: 4.10; P = 0.045*; CI: 95%]。与其他基因型相比，骨桥蛋白基因（rs11730582）纯合子[2/2 (CC)]的受试者更易受EARR影响，且影响程度更大 [OR: 11.68; P < 0.039*; CI: 95%]。
骨桥蛋白基因（rs9138和rs11730582）的变异是正畸治疗后继发EARR遗传易感性的决定因素。
