Genetic structure of a population of Valparaiso. II. Distribution of two dental traits with anthropological importance

The frequency of Carabelli's cusp (27.24%) and shovel-shaped incisors (45.72%) were determined in a sample of students from the city of Valparaíso. These values are intermediate between those found in Caucasian and Mongolian populations. A sexual dimorphism was observed for shovel-shaped incisors; the relation of this trait to a socio-economic index and occlusal type is indicated. Carabelli's cusp is found to vary with the number of foreign ancestors of an individual and his or her ABO blood group and color vision. There is also evidence that Carabelli's cusp serves better as an ethnic marker in a mixed population such as ours than does shovel-shaped incisors. This is thought to be due to the less complicated genetic basis of the former. It is also shown that the two traits are independent in their expression.