Lithuanian University of Health Sciences, Medical Academy, Department of Orthodontics, Kaunas, Lithuania.
Department of Genetics, Lithuanian University of Health Sciences, Institute of Biology Systems and Genetic Research, Kaunas, Lithuania.
Sci Rep. 2018 May 29;8(1):8307. doi: 10.1038/s41598-018-26740-7.
The purpose of this investigation was to determine the impact of heritability on third molar agenesis in twins. The study sample consisted of 284 same sex twins (172 monozygotic and 112 dizygotic), whose mean ages were 19.7 ± 4.3 and 18.9 ± 4.8 years, respectively. The monozygotic group consisted of 36.3% males and 63.7% females, while the dizygotic group consisted of 50.1% males and 49.9% females. The zygosity of the twins was established using 15 specific DNA markers. The prevalence of third molar agenesis in monozygotic twins was 19.6%, which was higher than in the dizygotic twins group (15.50%) (p = 0.004). In both groups, third molar agenesis was more frequent in the maxilla than in the mandible (p = 0.000). Agenesis of the maxillary third molars was mostly affected by additive genetic factors (62-63%), with the common environment and the specific environment accounting for up to 25% and 13%, respectively. In contrast, agenesis of the lower third molars was associated with a higher additive genetic determination (81-83%), with the specific environment accounting for 17% to 19%. The study's conclusion is that the formation of the third molars follicle is strongly controlled by additive genetic factors.
本研究旨在探讨遗传因素对双胞胎第三磨牙缺失的影响。研究样本包括 284 对同性别双胞胎（172 对同卵双胞胎和 112 对异卵双胞胎），其平均年龄分别为 19.7±4.3 岁和 18.9±4.8 岁。同卵双胞胎组中男性占 36.3%，女性占 63.7%；而异卵双胞胎组中男性占 50.1%，女性占 49.9%。通过 15 个特定的 DNA 标记确定双胞胎的同卵性。同卵双胞胎中第三磨牙缺失的患病率为 19.6%，高于异卵双胞胎组（15.50%）（p=0.004）。在两组中，第三磨牙缺失在上颌中比在下颌中更为常见（p=0.000）。上颌第三磨牙缺失主要受加性遗传因素的影响（62-63%），共同环境和特殊环境分别占 25%和 13%。相比之下，下颌第三磨牙缺失与更高的加性遗传决定因素相关（81-83%），特殊环境占 17%至 19%。研究结论是，第三磨牙滤泡的形成受加性遗传因素的强烈控制。
