Boraas J C, Messer L B, Till M J
Department of Pediatric Dentistry, School of Dentistry, University of Minnesota, Minneapolis 55455.
J Dent Res. 1988 Sep;67(9):1150-5. doi: 10.1177/00220345880670090201.
The heritability of dental characteristics has been systematically studied in animals, human populations, families, and twins, but not in twins reared apart. Under the assumption that environmental factors are no different for monozygotic twins reared apart than for dizygotic twins reared apart, the present study measured the genetic variance of several dental characteristics in twins reared apart. Ninety-seven subjects (44 twin pairs, three triplet sets) of mean age 40.6 years (S.D. 11.7) were examined over a six-year period by means of clinical and radiographic examinations, study models, and dental history questionnaires. Characteristics assessed retrospectively were: dentate status, treatment status, treatment/caries status, tooth size, malalignment, occlusion, and morphology. Data were analyzed by two-way ANOVA, intraclass correlations, heritability estimates, and concordance. There was statistically significant resemblance within monozygotic but not dizygotic pairs in the number of teeth present (p less than 0.001), percentage of teeth and surfaces restored (p less than 0.001), percentage of teeth and surfaces restored or carious (p less than 0.001), tooth size (p less than 0.001), and malalignment (p less than 0.009). Intercanine and intermolar arch width showed significant resemblance within both monozygotic (p less than 0.001) and dizygotic (p less than 0.01, p less than 0.05) pairs, whereas overjet and overbite showed no significant resemblance within pairs. Morphological features (Carabelli's trait and mandibular first premolar groove configuration) were more highly concordant in monozygous than in dizygous twins. This study provides new evidence for a marked genetic component to dentate status and dental caries experience and confirms previous reports of acknowledged inherited contributions to tooth size, malalignment, occlusion, and morphology.
牙齿特征的遗传力已在动物、人群、家庭和双胞胎中进行了系统研究，但未对分开抚养的双胞胎进行研究。在分开抚养的同卵双胞胎与分开抚养的异卵双胞胎的环境因素无差异这一假设下，本研究测量了分开抚养的双胞胎中几种牙齿特征的遗传方差。在六年时间里，通过临床和影像学检查、研究模型及牙科病史问卷，对平均年龄40.6岁（标准差11.7）的97名受试者（44对双胞胎、3组三胞胎）进行了检查。回顾性评估的特征包括：牙齿状态、治疗状态、治疗/龋齿状态、牙齿大小、牙列不齐、咬合及形态。数据通过双向方差分析、组内相关性、遗传力估计和一致性分析进行分析。在现存牙齿数量（p<0.001）、修复牙齿和牙面的百分比（p<0.001）、修复或患龋牙齿和牙面的百分比（p<0.001）、牙齿大小（p<0.001）和牙列不齐（p<0.009）方面，同卵双胞胎对之间存在统计学上的显著相似性，而异卵双胞胎对之间则不存在。尖牙间和磨牙间牙弓宽度在同卵双胞胎对（p<0.001）和异卵双胞胎对（p<0.01，p<0.05）中均显示出显著相似性，而覆盖和覆合在双胞胎对中未显示出显著相似性。形态特征（卡氏特征和下颌第一前磨牙沟形态）在同卵双胞胎中比在异卵双胞胎中更具一致性。本研究为牙齿状态和龋齿经历的显著遗传成分提供了新证据，并证实了先前关于牙齿大小、牙列不齐、咬合和形态的公认遗传贡献的报道。
