Comparison of four skeletal methods for the estimation of age at death on white and black adults

When analyzing human adult skeletal remains, it is often difficult to decide whether a single aging method will give a more reliable age estimation than a combination of methods. This study evaluates four macroscopic indicators for age estimation on 218 American White and Black individuals, ranging in age from 25 to 90 years of age, from the Terry collection. Individuals in the sample were selected to have a balanced race, sex, and age distribution. The following aging methods were applied to each skeleton by one experienced observer: the Suchey-Brooks (SB) pubic symphysis method, the Lovejoy auricular surface method, the monoradicular teeth Lamendin (LM) method, and the Işcan (IC) method for fourth ribs. The statistical study involved the evaluation of inaccuracy and bias (based on median age) for each age indicator and the combination of methods using Principal component analysis (PCA). Analysis was performed on the entire sample, then by race, then sex, and then age group (25-40 years, 41-60 years, and >60 years). PCA was the most accurate method for both racial groups when all age groups are analyzed together. When the sample was divided into age groups, SB was the most accurate for young adults (25-40 years) and LM was the most accurate for middle adults (41-60 years). After the age of 60, all methods are highly inaccurate, although IC gives the lowest inaccuracy. As regards bias, the study highlights the tendency of all methods to overestimate the age of young individuals and to underestimate in the older age group. No single skeletal indicator of age at death is ever likely to reflect accurately the many factors that accumulate with chronological age. In fact, one must use as many dental and skeletal indicators as possible. However, in order to maximize the potential of each method, in the final evaluation one should consider mainly the method or methods that have a higher accuracy for a particular age range.