Devi M S Anjana, Padmanabhan Sridevi
Department of Orthodontics and Dentofacial Orthopaedics, Faculty of Dental Sciences, Sri Ramachandra University, Chennai, India.
J Orthod. 2019 Mar;46(1):14-19. doi: 10.1177/1465312518820537. Epub 2019 Jan 23.
Maxillary canines are the second-most commonly impacted teeth. About two-thirds of the impacted maxillary canines are palatally impacted. Studies in the past have shown that 40% of cases with palatal impaction of maxillary canines presented with agenesis of third molars. Sporadic agenesis of third molars have been associated with polymorphisms in the MSX1 and PAX9 genes. The present study aims at evaluating the association between polymorphisms of PAX9, MSX1 and palatally impacted canines in a random population sample.
Fifty individuals with palatally impacted maxillary canines and 50 gender and age-matched controls were included in this study.
Single nucleotide polymorphisms (SNPs), rs12532 of MSX1 and rs2073247 of PAX9, were genotyped using polymerase chain reaction and restriction fragment length polymorphism. The significance of the differences among the groups was assessed by odds ratio and Chi-squared test with a 95% confidence interval.
Single nucleotide polymorphisms rs12532 [MSX1] and rs 2073247 [PAX9] showed a statistically significant association with palatal impaction of maxillary canines. In addition, the combined presence of the AG/CT genotypes of these genes in an individual caused a significant increase in the risk for palatal impaction.
These results suggest that the rs12532 and rs2073247 polymorphisms of genes MSX1 and PAX9 are positively associated with palatal impaction of maxillary canines. Future studies investigating various other SNPs of these genes in a larger sample of different populations could provide clinching details.
上颌尖牙是第二常见的阻生牙。约三分之二的上颌阻生尖牙为腭侧阻生。过去的研究表明,40% 的上颌尖牙腭侧阻生病例伴有第三磨牙缺失。第三磨牙的散发性缺失与 MSX1 和 PAX9 基因的多态性有关。本研究旨在评估 PAX9、MSX1 基因多态性与随机人群样本中腭侧阻生尖牙之间的关联。
本研究纳入了 50 例腭侧阻生上颌尖牙患者以及 50 例性别和年龄匹配的对照者。
采用聚合酶链反应和限制性片段长度多态性技术对 MSX1 基因的单核苷酸多态性(SNP)rs12532 和 PAX9 基因的 rs2073247 进行基因分型。通过比值比和卡方检验评估组间差异的显著性,并计算 95% 置信区间。
单核苷酸多态性 rs12532[MSX1]和 rs2073247[PAX9]与上颌尖牙腭侧阻生具有统计学意义的关联。此外,个体中这些基因的 AG/CT 基因型共同存在会显著增加腭侧阻生的风险。
这些结果表明,MSX1 和 PAX9 基因的 rs12532 和 rs2073247 多态性与上颌尖牙腭侧阻生呈正相关。未来在更大规模的不同人群样本中研究这些基因的其他各种 SNP 可能会提供确凿的细节。