Morphometric Analysis of the Skull by Moire Contourography / 체질인류학회지

ABSTRACT

The non-metric analysis of the skulls is very useful for estimating sex and determination of ancestry, the accuracy tends to depend on the amount of experiences of the observers, and so inter-observer errors might be happened. Many researchers are trying to find out more objective methods for determination of ancestry. The purpose of this presentation is to show the usefulness of moire contourography for analyzing the skull. The master screen that is similar to the gratings was made by steel rods, which were arranged as equally spaced parallel lines. Halogen light source was illuminated by lantern slide projector. The skeletal materials were documented crania, composed of 87 male and 47 female, from William M. Bass Donated Skeletal Collection housed at the Department of Anthropology, University of Tennessee. The skulls were placed just behind the master screen as anatomical position using cubic craniophore. The angle between the light source and camera was 65degrees, the distance between camera and the master screen was 1.2 m. Frontal view, left lateral and right lateral view were taken. From the frontal view, fringe patterns were analyzed for first five contour lines which were mainly located around the Glabella. The results were as followed; Type I for male was 53% and female was 4%; Type II for male was 29% and female was 2%; Type III for male was 2% and female was 15%; Type IV for male was 6% and female was 55%. From the lateral view, fringe patterns were analyzed for first four contour lines. However, first and second contour lines were critical to determine the shape and the results were as followed; Type I for male was 52% and female was 22%; Type II for male was 38% and female was 26%; Type III for male was 8% and female was 17%; Type IV for male was 2% and female was 35%. According to this study, different fringe patterns might be dependent on the degree of development of bone marker such as Glabella, Supercillary arch, Euryon and Mastoid process. For example, Supercillary arches were very well developed and slope of forehead above the Glabella was declined, fringe pattern showed reverse triangle shape. If Supercillary arches were poorly developed and slope of forehead above the Glabella was flat, fringe pattern showed home plate shape. The present research shows that moire contourography might be used as more objective methods for estimating sex. And it would be helpful to determine the ancestry when the lateral aspects were analyzed. In the future, continuing study need to be performed with same master screen for different ancestry.