Palaeoradiography contributes to her identification.
St Mary and St Eanswythe's Parish Church, in Folkstone, England. Up until now the bones held by the church were only suspected of by St Eanswythe, but now they are confirmed.
Back in mid January I posted about an ecclesial mandible x-ray. I couldn't give too much away, but I was approached to x-ray the suspected remains of St Eanswythe by the archaeological department of Canterbury Christ Church University (in cahoots with the Canterbury Archaeological Trust). I was honored to be involved in the investigation of these bones which were suspected to be a saint from c.650-690 AD. I cannot divulge too much detail, as truly I don't know her full story, but suffice to say the bones were found within a cavity at her church and then suspected to be the saint. The mandible x-ray, which at the moment I cannot share, helped to age the individual due to the developmental status of her third molar (the wisdom tooth). Conservative estimates can place her anywhere between 17-21 year of age at death.
Ironically, had she died later in life we would have struggled to age her from the wisdom tooth alone. The remains, once restored and preserved, are the earliest surviving Anglo Saxon saint from the 7th century AD and the only surviving remains of Kentish royalty.
A Roman-age mandible from the Hallet's garage excavation in Canterbury. As with the Eanswythe mandible, this particular specimen has been broken in two, leaving only half of the mandible to be imaged. The wisdom tooth is shown unerupted (along with a plethora of other teeth). Knowing the typical eruption rates of different teeth gives a relatively reliable indication of age at death.
My MSc in Forensic Radiography touched upon the use of dental radiography and computed tomography for aging of individuals. I suggested to my archaeological counterparts that I am overly biased towards radiography as an investigative method, however I believe I am somewhat uniquely placed to make use of both disciplines when interpreting the remains. As mentioned in previous posts, the digital data created through digital radiography allows for much greater levels of analysis than chemical-film radiography (still in use in many archaeological commercial enterprises).
The digital x-rays are recorded as DICOM files (Digital Imaging and Communications in Medicine), containing a spatial element that allows direct measurement of anatomy. This makes several assumptions though; all parts of the specimen are flat against the detector during imaging, the position of the x-ray tube (relative to the detector) is suitable and that the tube and detector are parallel to each other. A three-dimensional object/specimen would have portions which are not demonstrated accurately, with differing degrees of image distortion. The image shown above demonstrates this well - the front portion of the mandible (the bottom incisors) are superimposed and further away from the detector, whilst the 'back' of the mandible is demonstrated accurately due to it being close and parallel to the detector. A photo or diagram may be needed to convey this better!
With the DICOM images it is possible to measure the tooth size, angle of eruption and relationship to other structures. It may even be possible to estimate the bone density, but I would need to investigate this further. I used the Demirjian system for dental aging, although this is based upon a modern population (certainly not 7th century AD Britain!) and is only a loose guide until further analysis is undertaken.
I look forward to analysing the data with my colleagues to learn more about the remains. It is intended to publish the findings in due course.
A random image from Wikipaedia for the church of St Mary and St Eanswythe, Folkstone.
Mandible x-ray by the author from the Hallet's garage excavation (Canterbury) collection. With kind permission of Canterbury Archaeological Trust.