Ji Eun Kim

JI EUN KIM, Midwestern University, Downers Grove, Illinois, was approved funding in October 2022 to aid research on “Mapping Variation in Skeletal Aging with Quantitative Ultrasound Cortical Bone Speed of Sound and Its Potential as a Novel Age-at-death Estimator.” Age-at-death estimation from the adult skeleton remains challenging after midlife due to lack of predictability and objectivity of traditional age indicators. One solution is assessing cortical bone density loss, a biological change that begins after 50-60 years of age. In this study, we evaluate the use of clinical quantitative ultrasound (QUS), a non-invasive, portable, and cost-effective technology, as a novel method for estimating bone mineral density in anatomical and skeletonized donors. We specifically collected speed of sound readings from the radius, tibia, 3rd phalanx, and 5th metatarsal which are elements that are frequently preserved in archaeological/forensic context. Additionally, we explored microstructural properties of ribs using micro-CT imaging. Our findings show that clinical QUS can reliably estimate bone density from skeletonized individuals after death and capture consistent decline of bone density with age with sex-specific trends. The integration of QUS with high-resolution rib imaging describing bone microarchitecture allows a more complete understanding of bone quality patterns and bone loss rates in association with age, sex, and health status. This multi-element, dual-method approach provides not only a promising approach to increase age estimation accuracy but also a new means to assess bone health to reconstruct living conditions of past populations more accurately.