系统发生学与进化生物学杂志

Craniometry Patterns of Nigerians and its Correlation with Chronological Age

Abstract

Willy Vidona , Oviosun Aiol

Cranial dimensions and cranial indices are considered as simplest and most efficient way to indicate facial differences and age variations. Cranial morphology and dimensions are used to evaluate various aspects of growth and development thus helping in population differentiation.

Aim: the study is to investigate the craniometrical patterns in the Nigerian population based on three dimensional computed tomographic data, with the objectives of determining the age of individuals in the eastern part of Nigeria as well as determining if the skull of individual varies with age using computed tomography.

Methodology: involves a descriptive study design with age determined using standard ageing techniques. 150 dry adult human skulls cases (male and female both) constituted the material for the present study between age group of 25-60 years. Data were scanned in the radiology department and the CT data were processed in a computer workstation at the department. The CT scan acquisition was performed with 1.5mm slice thickness and reconstruction was done with 1.0 m 2 m slice thickness. All the CT data were recorded using DICOM 3.0 as a medical image file format into CD-ROM. The segmentation techniques were used to identify the region of interest of the computed tomography image based on Hounsfield unit. The selected region was calculated into 3-D modem based on the traditional definition with the modification into 3D model. The anatomical landmarks in craniometrics study were: Glabella (GL), Bregma (BR), Opisthocranium (OPC), Nasion (NA), Basion (BA). The measurements were interpreted using statistical analysis and reported in form of comparism of the mean values and mean difference, standard deviation, and confidence interval in respect to the various landmarks. Analysis of variance was utilized with p-value 0.005 alpha level of significant.

Result: the total number of sample for each landmark group is 1050 which covers the range value of 6 with a minimum number 1 and maximum number 7. The total sum of all Landmarks d is 4,200. The mean statistics of the seven groups is 4.00 with standard error of 0.62. The total number of length is 1050 with range of 119. The length attracts the minimum and maximum value of 80 and 199 with total sum of 132282. The mean statistics is 125.98 with standard error of 0.740.