Head phenotypes based on cephalic index among Ukwuani people, in south-south Nigeria

Abstract

Background : Head shape based on cephalic index has been used by anthropologists as a measure of classifying humans. Cephalic index is derived from head length and head width. Objective : To find out the dominant head phenotypes based on cephalic index in relation to age. Design : A cross-sectional study. Setting : The Department of Human Anatomy and Cell Biology, Delta State University, Abraka, Nigeria, between February and September, 2011. Subjects : Six hundred and five people (grouped into 6-12 years, 13-19 years and 20 years and above) were recruited to participate the study. Results : The mean cephalic index at 6-12 years is 74.37 ± 3.09 (male=73.95 ± 2.93; female = 74.78 ± 3.20). At 13-19 years, the mean cephalic index is 74.71 ± 3.52 (male = 74.04 ± 3.35; females = 75.28 ± 3.57).The mean cephalic index at 20 years and above is 76.19 ± 3.26 (male=75.90 ± 3.32; females = 76.52 ± 3.23). The dominant head phenotype at 6-12 years is dolicocephalic including males and females. At 13-19 years head type is dolicocephalic; males and females are dolicocephalic and mesocephalic head type respectively. At 20 years and above, mesocephalic head type is dominant; males and females are dolicocephalic and mesocephalic head type respectively. Poor positive linear correlation exists between cephalic index and age. There is no significant difference between cephalic indices at 6-12 years and 13-19 years. There exist statistically significant differences between cephalic index at 20 years and above, and at 6-12 years and 13-19 years. Conclusion : This is relevant in anthropology and forensic science.