The effect of factors other than age upon skeletal age indicators in the adult.

CONTEXT: Estimation of adult age from skeletal remains is problematic due to the weak and variable relationship between age indicators and age.
OBJECTIVES: To assess the proportion of variation in age indicators that is associated with factors other than age and to attempt to identify what those factors might be.
METHODS: The paper focuses on frequently used adult bony age markers. A literature search (principally using Web of Science) is conducted to assess the proportion of variation in age indicators associated with factors other than age. The biology of these age markers is discussed, as are factors other than age that might affect their expression.
RESULTS: Typically, ∼60% of variation in bony age indicators is associated with factors other than age. Factors including inherent metabolic propensity to form bone in soft tissue, vitamin D status, hormonal and reproductive factors, energy balance, biomechanical variables and genetic factors may be responsible for this variation, but empirical studies are few.
CONCLUSION: Most variation in adult skeletal age markers is due to factors other than age; dry bone study of historic documented skeletal collections and high resolution CT scanning in modern cadavers or living individuals is needed to identify these factors.