Comparison of Male and Female Rib Sternal Ends and the Effects of Aging using Elliptical Fourier Analysis

Sex and age make up two of the main tenets of the biological profile. Most anthropologists would argue that sex is one of the most important aspects of the profile. When creating a biological profile, the first step is to estimate sex of the individual because this can affect age estimation using the os coxa or estimations of stature. Past studies have noted that even though ribs carry out the same function in males and females there are morphological differences that can affect age estimation using the ribs. This study uses Elliptical Fourier analysis to compare differences in overall shape of the male and female sternal rib end. It also explores how the shape of the sternal end of the rib is affected by skeletal aging processes. As other studies have noted the rate and pattern of costal cartilage ossification seem to exhibit trends based on sex and age of the individuals. For this reason, the amount or rate of ossification and ossification patterning were also explored. The results showed that for all features analyzed, age and sex were found to be key influencers with varying degrees. In the case of costal cartilage ossification this study found that rate of ossification was based more on age while sex was more of an influence for differences in ossification patterning on the sternal end of the rib. Further analysis also revealed that the degree that sex or age influenced the shape of the sternal was dependent on which rib was used, e.g., rib 1 or rib 5.