A comparative and correlational study of the cranial base in North American blacks

Abstract

The purpose of this investigation was to compare the cranial bases of blacks and whites in regard to length, angulation, and flexure, and to determine what proportion of the differences in facial measurements can be explained by the variability seen in the cranial base. Standardized cephalograms of 100 native-born North American black adults were traced, analyzed, and compared with white values. The measurements selected depicted dependency and independency from the cranial base. Mean differences between the races and the sexes were assessed with the Student's t test. Models of linear regression between the cranial base measurements and all other parameters were computed for both sexes and correlation coefficient values calculated. This study established that the length of the cranial base in North American blacks is significantly shorter from that of whites. A strong biologic relationship was demonstrated between the length of the cranial base of blacks and their denture bases, the palatal, and occlusal planes. The data suggest that most of the cephalometric differences between blacks and whites are not simply anatomic for measurements using sella nasion as their reference plane.