ABSTRACT
The comparative study of cephalometric indices among the Igede and Idoma ethnic groups of Benue State was undertaken due to lack of adequate cephalometry among Nigerians. The anthropometric characteristics of 425 apparently normal adults of ages 17 - 40 years of Igede and Idoma ethnic extractions of Benue State, Nigeria with no physical deformities of the face and head were randomly selected for this study. Satisfactorily characterizations between the two ethnic groups wereclearly established. Four hundred and twenty five subjects were used for the study of which 158 were Igede and 267 were Idoma with mean age of 22.60.45 and23.00.47 year respectively. The anthropometric variables measured were head length, head width, bizygomatic distance, upper facial length, lower facial length, total facial length, nose width and skull height from which the cephalometric indices were calculated. The result showed that there were statistically significant differences (P<0.05) in some of the measured variables between the Igede and Idoma tribes of Benue State. The variables that were significantly different include the head width (55.02.60; 59.01.30), head length (75.0.40; 77.081.10) and nose width (11.3210.080.19) respectively with correlation coefficient at P<0.01. The study derived a linear regression equation of cephalic indices with other anthropometric parameters from which age, head width, head length and skull height could be predicted if one variable is known. The result from the present study showed that the cephalic indices and facial presentations among the two tribes are similar and probably could be an indication of having the same genetic origin. It could also be that after having stayed together for long time in the same environment, that environmental factor could have given rise to similar cephalic indices and facial features. The result also showed a positive correlation between the head width and bizygomatic distance and other anthropometric variables which could be used to predict cephalic indices among the viii Igedeand Idoma ethnic groups of Benue State, Nigeria. The result of the present study showed that the Igede males and females had cephalic indices of 78.86 and 79.43 respectively while the Idoma males and females had cephalic indices of 78.43 and 79.60 respectively. These results showed that the dominant head form among the Idomaand Igede Ethnic groups weremexocephalic head form respectively. Facial indices showed dominant hypereuriprosopic face type for both ethnic groups. The cephalic index showed sexual dimorphism among the two ethnic groups while facial indices showered a significant gender differences in the two ethnic groups studied. The results showed that the data obtained from the present study could be used in forensic anthropology and in establishing similarities in face and headof the two ethnic groups of Idoma and Igede of Benue State of Nigeria.