The skulls of Viking-age Swedes, dated between the 10th and 12th centuries, suggest the population of the time was suffering from a wide variety of ailments.
Researchers from the University of Gothenburg and Västergötlands Museum in Sweden analyzed the human remains using modern computed tomography (CT) scans and found evidence of mouth diseases, jaw joint damage, sinus and ear infections, tooth decay, osteoarthritis, and other problems.
"There was much to look at," says odontologist Carolina Bertilsson, from the University of Gothenburg. "We found many signs of disease in these individuals."
"Exactly why we don't know. While we can't study the damage in the soft tissue because it's no longer there, we can see the traces left in the skeletal structures."
The team took a close look at 15 skulls collected from the well-known Varnhem Abbey archaeological site in the province of Västergötland. The skulls were taken from adults who died between the ages of 24 and 60.
Through CT scans – which are precise types of X-ray scans, taken in three dimensions – the researchers saw damage to both the surface and the interior of the skulls, and they mapped that damage to probable causes.
It's a demonstration of just how much valuable information can be revealed by these types of scans on these kinds of remains, giving us a better idea of how these people lived, back when there were far fewer treatments for pain and disease.
"Everyone knows what it's like to have pain somewhere, you can get quite desperate for help," says Bertilsson.
"But back then, they didn't have the medical and dental care we do, or the kind of pain relief – and antibiotics – we now have. If you developed an infection, it could stick around for a long time."
Some of the research team behind this study had previously looked at teeth recovered from the same site, finding extensive evidence of tooth decay and even some rudimentary attempts at dentistry.
Work has been ongoing at the Varnhem site for decades now. It's a significant religious landmark, once the largest church in Sweden, and is the resting place for three Swedish kings from the Middle Ages.
The researchers say that applying their CT scan approach to other ancient remains could reveal all kinds of new discoveries that wouldn't be spotted with a normal visual inspection – and without causing unnecessary damage.
"Very many of today's archaeological methods are invasive, with the need to remove bone or other tissue for analysis," says Bertilsson. "This way, we can keep the remains completely intact yet still extract a great deal of information."
The research has been published in the British Dental Journal Open.