Three Dimensional Quantitative Analyses of Human Pubic Symphyseal Morphology: Can Current Limitations of Skeletal Aging Methods Be Resolved?

During the past century, several aging methods based on pubic symphysis morphology have been introduced. Many of these methods represent modifications of the original method described by Todd (1920). Recently, Hoppa (2000) has explored some of the problems and challenges associated with using modern reference samples to estimate the pattern and rate of age related changes in bone morphology observed in past populations. His results outline the current limitations of skeletal aging methods, in particular, those that rely on changes to the pubic symphyseal face. In this paper, we introduce a novel approach that may, in future years, help alleviate some of these methodological problems. We present the results of quantitative analyses of the age-related morphological changes displayed by the Suchey-Brooks pubic symphysis casts. All twenty-four male and female casts were scanned using a 3D laser scanner and geometrically modeled. The resulting virtual 3D symphyseal faces were analyzed using various geometric analytical techniques enabling the extraction of quantitative data best representing qualitative features of interest. Preliminary results suggest the ability to quantitatively describe the age-related changes to the pubic symphysis may provide potential for future method refinement. Continuing research is committed to developing a computerized, web-accessible database of 3D pubic symphyseal faces from individuals of known age-at-death, sex, and biological affinity. It is hoped that this work will lead to further refinements of the pubic symphysis aging method, especially in regard to differences between populations, as well as serving as an education and research tool.