Ji Eun Kim

Age-at-death estimation of the post-maturation skeleton suffers from inaccuracy and bias due to individual variability in skeletal aging coupled with decreasing predictability of traditional macroscopic age indicators past midlife. To ascertain accurate and reliable age estimation, this project proposes to investigate aging variation in two ways: a systematic examination of factors (body size and biomechanical stress) linked to creating individual variation in skeletal aging and identifying/incorporating alternative age indicator(s) that is informative beyond the young/middle-aged group. The project introduces a new non-invasive and objective metric, quantitative ultrasound-based cortical bone speed of sound, to measure age-related bone loss and evaluates its utility as a new age indicator. Using anatomical cadaver and reference skeletal samples representing modern Americans, the project compares six anatomical sites (the radius, phalanx, rib, tibia, metatarsal, and pubic symphysis) and two different types of age indicators (cortical bone density vs. bone morphology). To explain synchronous (or asynchronous) aging processes between various age indicators, the project examines the covariation between age-related bone loss and body size or mechanical loading (i.e., weight-bearing vs. non-weight-bearing). Ultimately, the project seeks to contribute to reconstructing more realistic individual identity and demographic parameters of populations across time and space.