Radiologic Evaluation of the Orbital Index among the Igbo Ethnic Group of Nigeria
European Journal of Anatomy
Department of Anatomy, School of Basic Medical Sciences, College of Medical Sciences, University of Benin, Ugbowo, Benin City, Edo State, Nigeria
The two orbits in the human face serve as sockets for the eyeball and other visual apparatus. It is pyramidal in shape with the apex directed posteriorly and the base which forms the orbital margin located anteriorly. The purpose of this study was to radiologically evaluate the orbital index of the Igbo ethnic group of Nigeria. Three hundred and fifty frontal plain radiological films of the skull were obtained from the National Orthopaedic Hospital, Enugu, Nigeria. The films comprised of 217 males and 133 females aged between zero and seventy nine years (0-79 years). The maximal orbital height was measured from the frontal film as the maximum vertical distance between the superior and inferior orbital rims while the maximal orbital width was determined as the maximum horizontal distance between the medial and lateral orbital rims. The orbital indices were estimated from the data gathered using the formula: Orbital index=[maximal orbital height/maximal orbital width]*100. The analyses were done using Statistical Package for Social Sciences (SPSS) version 16.0. The results are reported as mean ± standard deviation. The orbital indices of both sides as well as both sexes were compared using the Student t-test. The differences were considered statistically significant when probability was less than 0.05 (P<0.05). The results showed that the mean orbital index was 73.09±13.47. This study also revealed that the orbital index was significantly higher (P<0.05) in males than in females. There were no statistically significant differences (P>0.05) between the right and left orbital indices in both sexes. It is recommended that further populationbased studies be carried out in different geographical locations.
adolescent; adult; aged; Article; child; ethnic group; female; human; Igbo (people); infant; inferior orbital rim; major clinical study; male; maximal orbital width; maximum horizontal distance; maximum vertical distance; middle aged; musculoskeletal system parameters; newborn; Nigeria; orbit; orbital height; orbital index; preschool child; school child; sex difference; skull radiography; superior orbital rim; very elderly