Neanderthals treated a dental cavity by drilling into the tooth

A 59,000-year-old Neanderthal tooth found in a Siberian cave shows signs of deliberate drilling to treat deep decay, pushing back the earliest evidence of dentistry by about 45,000 years.

The lower second molar – plagued by suspected bacterial decay – shows telltale marks from experienced drilling with a stone tool, in three stages, to the pulp. Although the procedure would have been excruciating, it likely relieved pain for the individual, who continued to chew with the tooth, perhaps for years, says Kseniya Kolobova of the Russian Academy of Sciences.

“Our discovery directly challenges assumptions about Neanderthal cognition, by showing that they were capable of causal reasoning about disease,” she says. “We trust the evidence provided by our microscopes.”

In the Altai Mountains of southwest Siberia, Russia – where Neanderthals migrated from Europe around 70,000 years ago – researchers discovered a lower molar with a large, irregularly shaped concavity that included three partially overlapping recesses throughout the pulp chamber.

At first, the team thought it was just a tooth broken before or after death, says Andrey Krivoshapkin, also of the Russian Academy of Sciences. But as more scientists examined the tooth, more questions arose about how the tooth had become misshapen — and whether it had been done on purpose. So far, the oldest evidence of useful dental work dates back 14,000 years in a Homo sapiens in Italy and involved scraping, not drilling.

The team asked Lydia Zotkina, also from the Russian Academy of Sciences, to perform in-depth analyzes of the marks on the tooth, revealing clear signs of human intervention, Krivoshapkin says. This led to further investigations using advanced imaging, which showed two cavities and scrapes consistent with repetitive toothpick use. It also revealed traces of turning sharp stone tools – probably made of jasper like the tools found in the same cave – directly in the cavity.

The shape of the hole resembles attempts at cavity repair in much later humans, with the likely intention of accessing the pulp chamber and removing tissue. The polished, rounded contours of the tooth indicate that the individual continued to use the tooth well after the drilling procedure, Kolobova says.

“At first, we were skeptical,” she says. “But little by little, we realized that we were facing something truly unprecedented: we were on the verge of rewriting a small but important chapter in Neanderthal history. »

To confirm their hypothesis, the researchers tried various drilling and scraping techniques in their laboratory using fine-tipped jasper stone tools and three Homo sapiens molars – two prehistoric specimens and one modern one with a cavity, recently extracted from the mouth of Zotkina. Neanderthal teeth are too rare and too old for such experiments, the researchers explain. The team managed to make similar holes in a 50-minute process that required precision and practice to avoid fracturing the tooth itself.

“It wasn’t a clumsy first attempt,” Krivoshapkin says of the Neanderthal case. “The operator knew where to drill, how deep to go, and when to stop. Regardless of who held the tool, the intervention demonstrates a remarkable level of cognitive and motor sophistication.”

The pain “would have been immense”, he adds – particularly for a Neanderthal, as genetic evidence suggests they were more sensitive to pain than Neanderthals. Homo sapiens TO DO. “Either the patient was extraordinarily stoic, or the person performing the treatment worked very quickly, or both.”

The treatment would likely have resulted in nerve death, resulting in pain relief. “It was invasive, targeted and functional,” Kolobova says.

Stefano Benazzi, of the University of Bologna, Italy, says he is convinced by the results, which are not surprising given the growing body of evidence showing the sophistication of Neanderthals. “These results highlight much more advanced cognitive and behavioral abilities than has long been thought,” he says.

However, this does not mean that Neanderthals had advanced dental skills, he cautions. “I feel like the pain was probably bad enough that they tried to scratch the affected area,” Benazzi says. “It might be more appropriate to call it ‘proto-dentistry,’ or something like that.”

Neanderthals, ancient men and rock art: France

Embark on a captivating journey through time exploring the main Neanderthal and Upper Paleolithic sites in the south of France, from Bordeaux to Montpellier.