Written in the bones… and teeth

IF THE eyes are the windows on the soul of the living, then the teeth, jaws and skeleton are, it seems, the keys to the physique, health and lifestyle of those who are long departed. Be they male or female, labourers or aristocrats, monks or military men; whether (and when) they had suffered from TB, malnutrition or leprosy and even where they grew up – all this information and much more can be divined from the skeletal remains of humans going back deep into prehistory.

“As far back as we have skeletons,” says Dr Alan Ogden, a palaeopathologist based in the Department of Archaeological Sciences at Bradford University. “In fact,” says the former dental surgeon, “I’ve just been involved with a human ancestor who precedes homo erectus.”

A million-year-old “patient” is perhaps as far away as it’s possible for Alan to get from the living ones he was used to dealing with over a long dental career, first in general and hospital practice for 12 years and then at Leeds Dental Institute as a clinical lecturer and specialist in restorative dentistry for another 20. But after hanging up his dentist’s drill and smock 11 years ago, this is precisely the subject he has dedicated himself to – using scientific and historical detective work to conjure an image of a person whose life once animated what are now skeletal remains.

“They were real people, they felt the world revolves around them much as we do now. My concern, as much as I can, is to bring them back to life,” says Alan.

Bony evidence

The very first job in bringing these people back to life is for Alan and his archaeologist colleagues to try to establish the period from which the skeletons come, as this influences the way in which the information gathered subsequently is interpreted. The habits and diet – and therefore the teeth and skeleton – of a medieval labourer, for example, were considerably different from those of a Victorian factory worker. “We have a whole galaxy of chemical and analytical techniques to help us tell when the bones were buried,” he says.

Although he sometimes works on archaeological digs, Alan refers to himself as a “backroom boy”, and the painstaking task of examining the remains usually starts with the careful transport of the skeletal material back to his laboratory. There he begins by “eyeballing the bones, using magnification when necessary, and then using X-rays, which will tell us a lot about their internal structure.” He also uses CT scanning and nuclear magnetic resonance spectroscopy, among a host of other techniques.

A first clue as to the person’s status, says Alan, is the “robusticity” of the bones. “In other words how much they were using their muscles. We get quite characteristic swellings on bones which show that a muscle was pulling on it regularly. And so you get a big difference in build between people who were agricultural or building labourers and, say, monks who spent all their time writing manuscripts. And you’ll see signs of ulceration and inflammation in the legs if the people were very sedentary.”

Diet and origin

Of course, build is just one of many parameters – after all, medieval noblemen, who were often military men, could be fit and strong too. Diet also leaves its imprint on the teeth and skeleton, with the poor during this period eating a much less refined, and therefore more abrasive, diet than that of the rich. “The lower down the pecking order you were, the coarser the food,” says Alan. This led to a clear difference between the social groups in terms of wear and tear on the molars.

But the results of good living were not always positive: “Sometimes the wealthy overdid it, so if they had a lot of meat, because vegetable food was seen as coarse and for the common people, they became prone to conditions like gout and disseminated idiopathic skeletal hyperostosis,” both of which leave characteristic signs on the skeleton.

Other clues in the teeth, such as their isotopic constituents, can point to the geographical area where the individual spent their childhood years. “Essentially, the chemicals embodied in teeth don’t change throughout a person’s life, thus giving away chemically where you spent your childhood.”

When combined with the fact that a person’s skeleton is replaced in its entirety every 20 years – and also shows signs of the locality in which the person was living during that period – this allows further conclusions to be drawn. “That’s one of the ways we can look at migration, in that the nearer the composition of the bone is to the area where people are found, the longer they have lived there,” says Alan.

In recent years, this has led to the overturning of the belief that expeditionary Vikings tended to marry local women. Among the female bones and teeth examined, a discrepancy was found between where they were buried and where they grew up, in this case Scandinavia, showing that Viking men often brought Norse women with them on their travels.

Technological advances are constantly pushing the boundaries and scanning electron microscopy is currently unlocking a wealth of fascinating information held in the enamel of teeth. This has to do with the health of the person at the time the enamel was being laid down.

As Alan explains: “If there are periods of poor nutrition or a child has a high temperature for a fortnight or so, you get patches of substandard enamel. You find grooves in their teeth called enamel hypoplasia, and because we know at what age each part of the tooth was formed, we can say this individual was very ill on several occasions between the ages of about seven and 11.”

Facial reconstruction

These are just a few of the many techniques that help to build the detailed picture that finally emerges from the archaeological team as a whole. But articulating that picture to the general public is often difficult, especially when you are dealing with advanced scientific processes and terminology.

However, one means of stimulating the public’s imagination is through facial reconstruction. It is a technique that Alan has become adept at in recent years. With a well-preserved skull and knowing the age and sex of the individual, it is possible to arrive at a fairly accurate representation of the person in question. “I still use the old-fashioned method which is to build up the underlying musculature in clay and then build up a layer of skin over the top,” he says.

He has famously reconstructed the features of “Gristhorpe Man”, probably the best preserved Bronze Age skeleton in the UK, as well as of those of a leper from a colony in Chichester and a medieval noblewoman buried at Stirling Castle. And as DNA techniques advance, it should one day be possible, he says, to add information on hair, eye and skin colour, making his stated aim of “bringing these people back to life” ever more real.

No complaints

Alan’s move into archaeology, a lifelong interest, has been something of a dream realised for the former dentist. While he loved his dental and teaching career, he had always felt a little frustrated by the need to specialise so early in life. “With anatomy, for instance, we learnt head and neck, a little bit of chest and virtually nothing else. And one of the things that I love now is that I know the anatomy of the whole body. The great thing is I can integrate dental anatomy and dental pathology into the bigger picture.”

It does mean, of course, that the question of patient contact has taken on a rather different complexion. Does it bother him? Not at all, he laughs. “With skeletons, I can go for a cup of coffee and they don’t complain.”

Adam Campbell is a freelance journalist and regular contributor to MDDUS publications