Smith P, Koyoumdjisky-Kaye E, Kalderon W, Stern D
Hebrew University, Hadassah School of Dental Medicine, Jerusalem, Israel.
Arch Oral Biol. 1987;32(1):5-9. doi: 10.1016/0003-9969(87)90146-4.
Dental traits were scored for second deciduous molars (dm2) and first permanent molars (M1) on casts of the dental arches of children aged 7-11 years. The children were from four different ethnic groups. The overall frequency of traits differed between the groups but the relative frequency of expression of traits in the two teeth showed a similar pattern. Traits such as continuous oblique ridge, Carabelli cusp, Y pattern and 7th cusp, that appear in the early stages of development, were more frequent in dm2 than in M1. Wrinkling, occlusal tubercles and marginal ridge cusps were more frequent in M1; these appear later. Thus the relative frequency of traits in these teeth reflects their ontogenetic history.
对7至11岁儿童牙弓模型上的第二乳磨牙（dm2）和第一恒磨牙（M1）的牙齿特征进行评分。这些儿童来自四个不同的种族群体。各群体之间特征的总体频率有所不同，但两种牙齿特征表达的相对频率呈现出相似的模式。在发育早期出现的特征，如连续斜嵴、卡氏尖、Y形和第七尖，在dm2中比在M1中更常见。皱纹、咬合结节和边缘嵴尖在M1中更常见；这些特征出现得较晚。因此，这些牙齿中特征的相对频率反映了它们的个体发育史。
