Skeletal Age-at-Death Estimation from the Pubic Symphysis: A Test of Three Methods in a Chinese Population

Estimating skeletal age-at death is challenging for forensic anthropologists. On the one hand, we are tasked with providing an age range for law enforcement that is narrow enough to be useful in the identification of missing persons, yet we must be careful not to sacrifice accuracy. This study tests three pubic symphyseal age estimation methods to investigate their accuracy on a Chinese sample. We hypothesize that methods providing overly narrow age intervals will be less accurate than methods providing broader age intervals. We also anticipate that this factor will play a more significant role in method performance than ethnicity. Three methods were evaluated on a sample of 73 Chinese males and 15 Chinese females between 16 and 60 years of age (mean = 33.9, standard deviation = 11.7). One method was derived on the Chinese population, and the other two are derived from American populations. Accuracy rates were calculated based on whether the known age fell into the age range approximated by the method; bias (over- or under-estimation of actual age) was also reported. As predicted, overly narrow age estimates did not perform well, with the lowest accuracy being the Chinese technique with the narrowest age ranges (59% accuracy). Ethnicity does not appear to affect accuracy as much as the range of the age interval. However, a detectable trend in bias exists when methods based on the American population are applied to the Chinese population. American methods underestimate age in Chinese skeletons. This bias was not detected with the Chinese method.