全新世中国北方人群第一臼齿齿冠面积和齿尖相对面积的测量分析

通过对532枚中国北方地区新石器时代到青铜时代和铁器时代人类上、下颌骨第一臼齿(M1和M1)齿冠面积和齿尖面积的测量和分析, 得到以下关于中国北方近代人群牙齿尺寸的准确数据和变异情况的结果: 两性M1和M1齿冠面积存在显著性差异, 男性齿冠面积大于女性齿冠面积, 齿尖相对面积不存在性别差异; 从新石器时代到青铜时代男性M1和M1分别缩小了1.16%和4.96%, 女性分别缩小了5.68%和6.11%,青铜时代到铁器时代齿冠面积无明显变化; M1颊侧尖相对基底面积大于舌侧尖, 形成齿尖大小差异的原因很可能是在人类演化过程中, 齿冠面积整体缩小的趋势下, 为使咬合面最大化使用, 各齿尖朝着更利于扩大咬合面基底面积的方式进化的结果; 世界各地区近代人群M1和M1各齿尖大小顺序基本一致, 其中M1为原尖>前尖>后尖>次尖, M1下原尖最大, 下次小尖最小, 其他三个齿尖面积非常接近, 不存在明显大小变化。

Measurement Analysis of the Crown Base Area and Cusp Base Area of the M1 of Northern Chinese in the Holocene

From measurement and analysis of the crown base area and relative cusp base area of M1and M1 of 532 teeth from northern China ranging from Neolithic to the Iron Age, we gain an understanding of northern Chinese dental traits. There are obvious differences in amphiprotic crown base area of M1and M1 with males larger than females. Relative cusp base area shows no sex differences. The male M1and M1 shrank 1.16% and 4.96% respectively, the female 5.68% and 6.11% form the Neolithic to the Bronze Age with no obvious variation from Bronze to Iron Age. When the crown base area shrank, the prongs evolved in a way that the occlusal surface can be enlarged to make the best use of the occlusal surface, and thus the relative cusp base area formed. Throughout the world, the size order of modern prongs is nearly the same. We conclude the order of the area of the prongs in M1 is protocone > paracone > metacone > mypocone. In M1 the area of the protoconid is the largest while the hypoconulid is the smallest. Areas of the other prongs are almost the same.