Anderson D L, Popovich F
Am J Phys Anthropol. 1977 Nov;47(3):381-5. doi: 10.1002/ajpa.1330470306.
Although first permanent molar hypoconulid absence, third molar agenesis, and small tooth size are all part of evolutionary trend of dental retardation, each bears a different relationship to dental caries. Caries prevalence in the maxillary and mandibular permanent first molars of the Burlington Research Centre serial experimental group at age 16 years was less in the children whose first molars were missing the hypoconulid. Conversely, caries prevalence in mandibular first molars was greater in the children who had agenesis of third molars. The extraction of first molars due to caries was more frequent in children with agenesis of third molars, less frequent in those with absence of hypoconulids of the first molars and unrelated to tooth size. Caries prevalence was less in small teeth, and occurred least in the small mandibular first molars with four cusps. Whereas this is in harmony with the hypothesis that evolutionary dental reductions resulted from the pressure of caries, the increased prevalence of caries and extractions coinciding with third molar agenesis does not support this view. In addition, agenesis of hypoconulids and agenesis of third molars were related to changes in structures unrelated to caries.
尽管第一恒磨牙远中尖缺失、第三磨牙先天缺失和牙齿体积小都是牙齿发育迟缓进化趋势的一部分，但它们与龋齿的关系各不相同。在伯灵顿研究中心系列实验组中，16岁儿童上颌和下颌第一恒磨牙的龋齿患病率在第一磨牙缺失远中尖的儿童中较低。相反，第三磨牙先天缺失的儿童下颌第一磨牙的龋齿患病率较高。因龋齿拔除第一磨牙的情况在第三磨牙先天缺失的儿童中更常见，在第一磨牙远中尖缺失的儿童中较少见，且与牙齿大小无关。小牙齿的龋齿患病率较低，在有四个牙尖的下颌第一小磨牙中发生率最低。虽然这与龋齿压力导致牙齿进化性缩小的假设一致，但与第三磨牙先天缺失同时出现的龋齿患病率和拔牙率增加并不支持这一观点。此外，远中尖缺失和第三磨牙先天缺失与与龋齿无关的结构变化有关。
