Aging sub-adults from long bone length which method is advisable? Samantha Tipper & Charlotte Primeau which method is best? 1
2
1: Durham University, 2: University of Dundee Presented at the Forensic Archaeology, Anthropology, and Ecology Symposium 2017. 12th of June, University College London
INTRODUCTION:
When ageing sub-adult skeletal remains, the most accurate method is using dental development. However, when teeth are not available, diaphyseal lengths can be used, but with less accuracy. The aim of this study is to investigate which method, would be most applicable, when estimating bone age from femora, when teeth are not available for aging archeological subadults.
generally used by osteoarchaeologists is Maresh (1970). Data from Maresh (1970) was derived from living children of the mid 20th-century of known age and sex with lengths of diaphyses measured from x-ray images. Concerns on use of this data as an ostearcheological ageing technique have been raised. Rissech et al. (2008) was chosen as this study published regression equations from several measurements of the femora, including diaphyseal length. Their data was also archaeological (18th to 20th century), but with documented age and sex, so is likely more appropriate than Maresh (1970) to use when ageing archeological sub-adults.
MATERIAL & METHODS: Seventeen Anglo Saxon sub-adults, curated by SHARP at Sedgeford, Norfolk, were aged by dental development using AlQahtani et al. (2010), (figure 1). Length of femora was measured (figure 3) and age estimated using three different methods: table data from a modern population (Maresh, 1970), quadratic regression equations developed from a Danish archeological population (1050-1526 AD) (Primeau et al. 2016) and, lastly, from a linear regression equation based on an archeological population (post medieval) with known ages (Rissech et al. 2008).
DISCUSSION: For diaphyseal lengths the data
The method of Primeau et al. (2016) was chosen as this study published linear regression as well as quadratic regression equations based on a medieval archeological population, but have the added advantage of available equations for all long bones. Figure 1. Mandible of a circa 12-15 year old child (SHARP collection)
RESULTS: See figure 2. Estimated bone ages using the method of Maresh (1970), showed the largest discrepancy to dental age, with a mean difference of -2.3 years. For Primeau et al. (2016) there was a mean difference of -0.4 years. For Rissech et al. (2008) there was a mean difference of 0.3 years.
The large discrepancies between the estimated ages when using the method based on modern data (Maresh, 1970) and the two methods developed on archaeological data (Rissech et al. 2008 and Primeau et al. 2016) may . be attributed to two main reasons: 1) differences in methodology (between using radiographic images vs. dry bone measurements), and 2) a difference in growth pattern between a modern population and that of archaeological populations. The authors acknowledge the small sample size in this study, but it is a preliminary study and the hope is to develop this study further. Acknowledgements: The authors would like to thank Sedgeford Historical and Archaeological Research Project (SHARP) for access to the skeletal collection and in particular Martin Hatton and Ray Baldry for the help and support with this project. Figure 3: Non-adult femora (Durham University Teaching Collection)
CONCLUSION: It is concluded that Maresh (1970) is
Figure 2: Estimated dental ages of the seventeen sub-adults with their corresponding bone ages using the three different methods REFERENCES: • AlQahtani et al. 2010. The London Atlas of Human Tooth Development and Eruption. AJPA 142(3): pp. 481 – 490. • Maresh MM. 1970. Measurements from roentgenograms. In: Scheuer L, Black S. 2000. Developmental Juvenile Osteology. Academic Press: San Diego. p. 394. • Primeau et al. 2016. A method for estimating age of medieval sub-adults from infancy to adulthood based on long bone length. AJPA 159(1): pp. 135-145. • Rissech et al. 2008. Development of the femur – implications for age and sex determination. Forensic Sci Int 180: pp. 1–9.
the least accurate method in estimating sub-adult age from long bone length compared to dental age and therefore is not a reliable method. Using Rissech et al. (2008) or Primeau et al. (2016), will both give a bone age closer to dental age. The difference in age between applying the two latter methods is a mean difference of 0.7 years. Rissech et al. (2008) has a bone age closer to dental age compared to Primeau et al. (2016). However, Primeau et al. 2016 is available for all long bones, so may be a more consistent method for a fragmented skeletal population. Full article: Primeau, C. & Tipper, S. 2017. Aging archeological subadults from femur length – which method is advisable? The Society for Archaeological Sciences Bulletin, vol. 40, no. 1, pp. 2-8. Corresponding author: Charlotte Primeau,
[email protected]
