Estimating age at death from skeletal remains can be done with relative accuracy
when a skeleton is complete, however incomplete and/or poorly preserved skeletons
pose a problem in assigning an accurate age range to unknown remains. Techniques
for determining age at death from the microstructure of bone have shown to be
relatively accurate in North American and European populations but, until recently,
had not been attempted on a South African group. This technique is based on the fact
that bone remodels and changes throughout an individual’s life.
The purpose of this study was to develop standards for estimating age at death,
using bone microstructure, that are applicable to a South African population. The
sample consisted of 146 individuals (105 males and 41 females) of known age and
sex. A 0.2 cm x 1.0 cm sample was removed from the anterior surface of the femur,
and slides were prepared according to standard histological methodology. Ten
variables, which included the total osteon count (measurable and non-measurable), the
average Haversian canal diameter, the average number of lamellae per osteon, the
total number of osteon fragments, the number of non-haversian canals, the total
number of resorption spaces and the average percentage of osteonal bone,
unremodeled bone and fragmental bone were assessed. The relationship between the
changes in each of the variables with age was examined. Four variables demonstrated
significant correlation with age and included the total osteon count (r = 0.53), the
percentage unremodeled bone (r = -0.53), the total number of non-haversian canals (r
= -0.55) and the average percentage of fragmental bone (r = 0.55). These variables
were then used to calculate single and multiple linear regression formulae to
determine age. Coefficient of determination (r2) for multiple regression analyses
ranged from r2 = 0.27 to 0.42. The general range of the standard error of the estimate
(SEE) for this study ranged between 13.31 and 14.04 years and is similar to the results
of previous studies. Various factors may have contributed to low r2 values, such as
poor nutrition, mechanical stress to the bones and misreporting of age of the
individuals in the sample. The microscopic techniques appear to not be more accurate
than macroscopic methods for estimating age at death, but can be useful in situations
were remains are fragmentary or in combination with macroscopic methods.
