Riga Alessandro, Belcastro Maria Giovanna, Moggi-Cecchi Jacopo
Department of Biological, Geological and Environmental Sciences, University of Bologna, 40126, Bologna, Italy.
Am J Phys Anthropol. 2014 Mar;153(3):397-407. doi: 10.1002/ajpa.22438. Epub 2013 Nov 22.
Teeth are an important model for developmental studies but, despite an extensive literature on the genetics of dental development, little is known about the environmental influences on dental morphology. Here we test whether and to what extent the environment plays a role in producing morphological variation in human teeth. We selected a sample of modern human skulls and used dental enamel hypoplasia as an environmental stress marker to identify two groups with different stress levels, referred to as SG ("stressed" group) and NSG ("nonstressed" group). We collected data on the occurrence and the relative development of 15 morphological traits on upper molars using a standard methodology (ASU-DAS system) and then we compared the frequencies of the traits in the two groups. Overall, the results suggest that (a) stressors like malnutrition and/or systemic diseases have a significant effect on upper molar morphology; (b) stress generates a developmental response which increases the morphological variability of the SG; and (c) the increase in variability is directional, since individuals belonging to the SG have more developed and extra cusps. These results are consistent with the expectations of the current model of dental development.
牙齿是发育研究的重要模型，然而，尽管有大量关于牙齿发育遗传学的文献，但对于环境对牙齿形态的影响却知之甚少。在此，我们测试环境是否以及在多大程度上对人类牙齿形态变异起作用。我们选取了一组现代人类头骨样本，并使用牙釉质发育不全作为环境压力标记，以识别出两个具有不同压力水平的组，分别称为SG（“压力”组）和NSG（“无压力”组）。我们使用标准方法（亚利桑那州立大学牙龄评估系统，ASU - DAS系统）收集了上颌磨牙15种形态特征的出现情况和相对发育数据，然后比较了两组中这些特征的频率。总体而言，结果表明：（a）营养不良和/或全身性疾病等压力源对上颌磨牙形态有显著影响；（b）压力会产生一种发育反应，增加SG组的形态变异性；（c）变异性的增加是有方向性的，因为属于SG组的个体有更发达的额外牙尖。这些结果与当前牙齿发育模型的预期一致。
