When Andrew Shelley, a dentist working with the School of Dentistry at the University of Manchester, contacted me to ask if the Museum has an edentulous mandible in its collection, my first instinct was to reach for the dictionary. As it turned out, an edentulous mandible is one that has lost all its teeth and I’d seen a specimen whilst working on the Heronbridge skeletons with Dr Robert Connolly during preparations for the Ancient Worlds displays.
It was one of the specimens that sadly has no associated information except for a label with the letter ‘C’. We did not know what that means nor how old the mandible was but the label suggested it was of 19th century date. I duly confirmed that we did indeed have an edentulous mandible. Andrew proposed to scan and x-ray the mandible and to use the images in his research. He is investigating the best ways of imaging patients who are unfortunate enough to have lost all their lower teeth and require dental implants to support a removable denture.
What Andrew told me next was slightly worrying because, in order to replicate the appearance of an x-ray or scan taken of a living patient, the mandible had to be soaked in water. This would give the appearance of tissue and blood surrounding the jawbone. Ordinarily soaking a museum object in water is the last thing curators want to do (unless it’s waterlogged wood or some other organic material). However, we did not know where the specimen came from and Andrew’s research will be of benefit to real life patients. My first response was to seek the advice of colleagues in conservation. So much depended on ground conditions in which the mandible had been buried but after discussing the matter with Irit Narkiss in the conservation team at the Manchester Museum we decided to proceed cautiously.
So it was in the first weeks of January I found myself in the School of Dentistry watching the process of x-raying the mandible. Most people can be forgiven for feeling a little apprehensive about a visit to the dentist’s but in this case but in this case I can honestly say I had been positively looking forward to it.
The mandible had to be supported in a head-shaped container and Andrew positioned some human vertebrae or neck bones in the container to make the x-rays look even more convincing. The mandible in its bath of water was x-rayed and scanned in the same way as a living patient.
The mandible was fitted with a denture in the same way as a modern patient as can be seen in the image below.
The aim is to find out how dentists’ treatment is affected by the different imaging techniques. In some cases the required information can be gained by plain x-ray film rather than exposing the patient to a higher level of radiation from a dental CT scan. It may be that, in some cases, the treatment plan would be the same regardless of which imaging technique is used. Andrew hopes that the project will lead to guidelines for dentists that will help them choose the most efficient imaging technique for each case and so reduce both the radiation dose and expense.
This is not the end of the story because Andrew has to find 6-8 edentulous mandibles for his study. The Manchester Museum is pleased that it has been able to help colleagues in the wider university by making available a specimen in the collections and that this work will benefit patients in dentistry.
As for the mandible that was soaked in water, Irit Narkiss informs me that it has dried out nicely, apparently no worse the wear for its recent outing. We look forward to hearing in due course from Andrew how his work progresses.