Sex Determination of the Fragmented Pelvis Using Euclidean Distance Matrix Analysis

Joan A. Bytheway

PhD Thesis 2003

There are various features of the human skeleton that have been used to assess sex. Features of the pelvis have been found to exhibit the most accurate estimates of sex determination. Methods developed to analyze the pelvis for sex determination include observational and morphometric techiniques. Both methods are dependent upon the presence of particular morphological features used in the analysis. Some observational features used for sex determination include the sub-pubic angle, the ventral arc, and the width of the pubis. Because these features are located on more fragile areas of the pelvis they are often missing when found in archeological or forensic contexts. The results in the use of features of the pelvis or skull that produce less accurate estimates. Morphometric techniques require that all points of measurement be present for analysis. If one landmark is missing, other morphometric techniques using different landmarks must be done, or the specimen must be eliminated from the analysis.

This study tests the hypothesis that Euclidean Distance Matrix analysis (EDMA) can reveal that the regions of the human pelvis that are durable and more frequently preserved could be used with a 95% confidence level to distinguish between male and female pelves. Thirty-six landmarks consisting of traditional, fuzzy, and constructed were identified on 240 male and female pelves. Male pelves consisted of adult White males (N=50), adult Black males (N=50), and adult Asian males (N=40). Female pelves consisted of adult white females (N=50) and adult Black females (N=50). Each landmark was digitized using a Microscribe 3D digitizer.

The results of EDMA show that there are significant landmarks found on the more durable regions of the pelvis. There are racial differences with the landmarks themselves. Landmarks significant on the Black pelvis consist of 10, 12, 16, and 27. Landmarks significant on the White pelvis consist of 10, 11, 12, 13, 27, and 28. In developing a morphometric technique for sex determination of the human pelvis landmarks 10, 12, and 27 could be used for both reaces.

The influential landmarks found on the more durable regions of the pelvis will be useful in developing a morphometric technique for sex determination.