Sex Differences in the Prenatal Human Deciduous Molar Crown

¹ Department of Restorative Dentistry, College of Dentistry, University of Kentucky, Lexington, Kentucky

This study was conducted to investigate molar crown size and to determine differences in prenatal deciduous molar tooth buds of males and females. The 4 deciduous molar tooth buds were dissected from 69 human fetuses, 19 through 38 weeks' intrauterine age (50 American Caucasians, 18 American Negroes, and 1 American Indian). There were 32 males and 37 females. A total of 525 tooth buds were stained with alizarin red S to show the presence and degree of calcified regions. The tooth buds selected for measurement were determined by the extent of their calcification. A total of 273 tooth buds met the requirements necessary to permit microscopic measurement for comparison of the prenatal molar crown size between the two groups, male and female. Dimensions studied for the 4 deciduous molars totaled 28.

The data obtained from the sample were analyzed statistically for homogeneity of variance and for significant differences in the mean size of the tooth bud crowns for the two groups.

The results of the analyses indicated that the means of six of the 28 dimensions were significantly different at the 5 or 1 percent level of probability. These results were sufficient to indicate the existence of sex differences in the prenatal deciduous molar crown size.