A Computational Framework for Age-at-Death Estimation from the Skeleton: Surface and Outline Analysis of 3D Laser Scans of the Adult Pubic Symphysis

In forensic anthropology, age-at-death estimation typically requires the macroscopic assessment of the skeletal indicator and its association with a phase or score. High subjectivity and error are the recognized disadvantages of this approach, creating a need for alternative tools that enable the objective and mathematically robust assessment of true chronological age. We describe, here, three fully computational, quantitative shape analysis methods and a combinatory approach that make use of three-dimensional laser scans of the pubic symphysis. We report a novel age-related shape measure, focusing on the changes observed in the ventral margin curvature, and refine two former methods, whose measures capture the flatness of the symphyseal surface. We show how we can decrease age-estimation error and improve prior results by combining these outline and surface measures in two multivariate regression models. The presented models produce objective age-estimates that are comparable to current practices with root-mean-square-errors between 13.7 and 16.5 years.