Pelsmaekers B, Loos R, Carels C, Derom C, Vlietinck R
Department of Orthodontics, School of Dentistry, Oral Pathology and Oral Surgery, Faculty of Medicine, Catholic University of Leuven, Belgium.
J Dent Res. 1997 Jul;76(7):1337-40. doi: 10.1177/00220345970760070201.
It has been established in the literature that there is a major genetic impact on tooth size (Potter et al., 1976; Corruccini and Sharma, 1985; Sharma et al., 1985), tooth morphology (Kraus and Furr, 1952; Biggerstaff, 1970), and root formation (Garn et al., 1960; Green and Aszkler, 1970). None of the studies concerning root formation, however, used the more advanced method of path analysis and model fitting to estimate genetic influence. The aim of the present study was to determine the genetic and environmental influence on dental maturation. Dental age scores were determined on panoramic radiographs of 58 pairs of twins--26 monozygotic (MZ) and 32 dizygotic (DZ)--with the method of Demirjian et al. (1973). No mirror-image effect was found between the sides of the same individual or between twin members, so dental maturation seems to be symmetrical for both left and right sides of the mandible. Correlation coefficients were significantly higher in MZ than in DZ twins, which suggests a genetic influence. Model fitting showed that the variation in dental age was best explained by additive genetic influences (A-component) (43%) and by environmental factors common to both twins (C-component) (50%). The specific environment (E-component) added only 8% to the model. The importance of the common environmental factor can be explained by the fact that twins, being raised together, share the same prenatal, natal, and immediate post-natal conditions that are of importance for the formation of the teeth.
文献中已证实，基因对牙齿大小（波特等人，1976年；科鲁奇尼和夏尔马，1985年；夏尔马等人，1985年）、牙齿形态（克劳斯和弗尔，1952年；比格斯塔夫，1970年）以及牙根形成（加恩等人，1960年；格林和阿斯克莱尔，1970年）具有重大影响。然而，关于牙根形成的研究均未采用更先进的路径分析和模型拟合方法来估计基因影响。本研究的目的是确定基因和环境对牙齿成熟的影响。采用德米尔坚等人（1973年）的方法，对58对双胞胎——26对同卵双胞胎（MZ）和32对异卵双胞胎（DZ）——的全景X线片确定牙齿年龄得分。在同一个体两侧或双胞胎成员之间未发现镜像效应，因此牙齿成熟在下颌骨的左右两侧似乎是对称的。同卵双胞胎的相关系数显著高于异卵双胞胎，这表明存在基因影响。模型拟合表明，牙齿年龄的变异最好由加性基因影响（A成分）（43%）和双胞胎共有的环境因素（C成分）（50%）来解释。特定环境（E成分）仅为模型增加了8%。共同环境因素的重要性可以通过以下事实来解释：一起成长的双胞胎共享对牙齿形成至关重要的相同产前、出生时和出生后即刻的条件。
