CROWN CHARACTERS OF THE DECIDUOUS DENTITION OF THE JAPANESE-AMERICAN HYBRIDS

Abstract

This chapter reviews crown characters of the deciduous dentition of the Japanese–American hybrids. Since 1949, studies of the physical traits of Japanese–American hybrids have been carried out by the members of the Department of Anthropology, University of Tokyo, under the direction of Professor Suda. The children studied were born of Japanese mothers and American fathers, including both Whites and Negroes, after World War II. They were brought up in one of the institutions for such orphans, the Elizabeth Sanders Home at Oiso, located some fifty miles southwest of Tokyo. Anthropological studies of these children have been undertaken twice a year. In addition to recording anthropometric data, X-ray studies of hand and foot bones, skin color tests, motor performance tests, dental studies, and psychiatric tests were also done. The hybrid groups generally show an intermediate pattern of distribution between the racial groups of their parents. In some characters, however, they show a closer resemblance or inclination to one of the parents. The hybrid groups are closer to the Japanese as regards the cusp development of the deciduous upper first molars but are nearer to the Americans when considering Carabelli's cusp in the deciduous upper second molars.