The 84th Annual Meeting of the American Association of Physical Anthropologists (2015)


Back to basics: Understanding the role of biological processes in adult skeletal age estimation

CATHERINE E. MERRITT.

Department of Anthropology, University of Toronto

March 27, 2015 11:15, Grand Ballroom C Add to calendar

Established skeletal age estimation methods have low reliability when applied to adults over the age of 40 years. After the age of 40 years, osteological changes are not always associated with specific stages of aging. Rather, they are strongly affected by factors that are not typically knowable in archaeological or forensic contexts: lifestyle, environment, and genetic predispositions. Recent studies have focused on refining statistical formulae to improve accuracy and precision (e.g. Bayesian statistics, cumulative probit models). While this work has made important contributions to the field, it has limitations. This paper suggests a return to basics: focusing on the underlying biological processes that inform skeletal changes in order to produce greater accuracy in adult age estimations.

This study applied the Buckberry and Chamberlain and Rougé-Maillart et al. methods to 764 skeletons from the Hamann-Todd and Bass Collections. Individuals ranged from 1.30m to 1.93m and 24kg to 99.8kg. ANOVAs were used to determine differences among individuals of varying body sizes. Results show that as body size increases, the surface texture, porosity, and apical activity scores are higher for larger individuals compared to smaller individuals. This study also found that femoral length and femoral head diameter are accurate proxies for stature and body mass. These findings show that body size affects the bone remodelling rates of the traits used in age estimation, and that understanding how body size influences underlying bone biology can improve the accuracy of adult skeletal age estimations.

This study was funded by the Social Sciences and Humanities Research Council, grant 752-2010-2124.