*Sinem Birant, Istanbul University-Cerrahpaşa, Faculty of Dentistry, Department of Pedodontics, Istanbul.
**Mine Koruyucu, Istanbul University, Faculty of Dentistry, Department of Pedodontics, Istanbul.
J Clin Pediatr Dent. 2022 Mar 1;46(2):160-170. doi: 10.17796/1053-4625-46.2.12.
The aim of this study is to investigate the relative contributions of genetic and environmental factors to variations in dental dimensions in a sample of Turkish twins, and to estimate heritability using dental casts.
The study samples were selected from the twin children between 3-15 years old who referred for their first dental examination. Fifty nine monozygotic and one hundred and forty three dizygotic twin pairs were examined in the study. The alginate impression material used to create the plaster model of maxilla and mandible. Anterior arch width, posterior arch width, arch length and arch circumference were measured on models prepared from measurements taken for both maxilla and mandible with digital caliper. The similarities and differences of the measurements were compared between pairs of twins and zygocytes. Morever, the effects of bad oral habits, bruxism, a result of psychosocial factors on measurements were examined. Statistical analysis was performed using Paired T Test, Wilcoxon Test and Mann Whitney U test.
A total of 404 dental models of 118 (29.2%) monozygotic and 286 (70.8%) dizygotic twins were evaluated. There was no statistical difference between sibling pairs in both monozygotic and dizygotic twins. The measurement similarity between twin siblings differed according to zygosity in all measurements (p<0.05). It has been observed that the finger sucking and mouth breathing affect the dental arch measurements (p<0.05).
These results indicate that the differences in dental arch dimensions between monozygotic twin pairs are less than the difference between dizygotic twin pairs.
本研究旨在通过对土耳其双胞胎样本的研究，调查遗传和环境因素对牙齿尺寸变化的相对贡献，并使用牙模估计遗传率。
该研究样本选自 3-15 岁首次接受牙科检查的双胞胎儿童。在研究中检查了 59 对同卵双胞胎和 143 对异卵双胞胎。使用藻酸盐印模材料来制作上颌和下颌的石膏模型。在前牙弓宽度、后牙弓宽度、牙弓长度和牙弓周长的测量中，采用数字卡尺对取自上颌和下颌的测量值进行模型制备。比较双胞胎和双生子之间测量值的相似性和差异。此外，还检查了不良口腔习惯、磨牙症等心理社会因素对测量值的影响。使用配对 T 检验、Wilcoxon 检验和 Mann Whitney U 检验进行统计分析。
共评估了 118 对（29.2%）同卵双胞胎和 286 对（70.8%）异卵双胞胎的 404 个牙模。同卵双胞胎和异卵双胞胎的同胞之间的测量值无统计学差异。在所有测量中，双胞胎兄弟姐妹之间的测量相似性因同卵双生子而异（p<0.05）。观察到吸吮手指和口呼吸会影响牙弓测量值（p<0.05）。
这些结果表明，同卵双胞胎之间牙弓尺寸的差异小于异卵双胞胎之间的差异。
