A Comparison between Anthropological (Dental Wear and Cranial Suture Closure Analysis) and Forensic (Dental Radiographic Approach) Methods of Age Estimation on a Middle Ages Human Sample from Beris Saqdrebi (Borjomi, Georgia)

Abstract

The traditional methods of age estimation applied on cranial remains diagnose age according to dental wear and sutures’ obliteration. These methods were applied to our bio-archaeological sample, which mostly consisted of skulls lacking the lower jaw, that were recovered from the crypt, where monks were probably laid to rest on stone shelves and after some time their skeletonized remains were moved to the lower part of the burial, so that they completely lost their anatomical connection. The aim of our research is to estimate which method can detect biological age more reliably, comparing the traditional anthropological methods based on dental wear and sutures and the forensic Cameriere’s radiographic approach on canines.
This research is of great importance for different reasons: in the monastery’s crypt an impressive number of subjects is buried, allegedly all belonging to the monastic part of the population and thus representing the largest assemblage of this kind in Georgia; the monastery itself was functioning for centuries, reflecting the influence of different historical and archaeological contexts. Founded in the 10^th century AD, abandoned in the 16^th century and recently re-opened after the archaeological excavations and restorations, the monastery and its cemetery yield an enormous amount of human skeletal remains belonging to a selected population sample and have huge potential both for anthropological data collection and comparison, and for the testing of new techniques.
X-ray method of age determination is based on an irreversible biological process, that is size regression of pulp, caused by the generation of secondary dentin. At a young age, the pulp chamber is quite big and it occupies the largest area of teeth on X-rays but as age increases it reduces its size. According to this approach, we can calculate age, based on the pulp regression phenomenon and apply a specific formula for single-rooted teeth. An important feature of this method is that it claims to be much more precise than other ones, the result in this case being a biological age and not a mere range. This radiographic approach turned to be extremely useful, especially in maturesenile age classes (45-50+), which with traditional anthropological techniques tend to be misdiagnosed and grouped in a single, flattened span.
Dental wear method (DWE) is not particularly suitable or reliable for our sample because this population and its dental evidence appear to be far from those selected for the proposed methods of dental wear, with a different pathological incidence and the biasing factor represented by the post-mortem loss of the anterior dentition due to taphonomic factors, while in the case of the X-ray method (CRX) and classical skull suture ossification method (LAS), these two methods show matching results both for younger age ranges (<45) and for older ones (45+).
The X-ray Cameriere’s method indicates for elderly subjects that 40-49 and 50-59 spans represent each 22% of studied individuals and 60-69 span represents 5% of the total sample. Ages older than 45+ would have gone misdiagnosed with traditional approaches while in this human population, 34,15% of the subjects appear to be aged more than 45+ and this percentage is definitely high, if compared to other solely monastic contexts in Europe. The mean age of the population has been calculated at 40.4 years.