Researchers excavating a Stone Age graveyard found a total of 11 teeth that had been drilled, including one that had apparently undergone a complex procedure to hollow out a cavity deep inside the tooth.
The discovery suggests a high level of technological sophistication, though the procedure, which involved drills tipped with shards of flint, could hardly have been a painless affair.

"The finding provides clear and compelling evidence that earlier people had knowledge of manipulation of dental hard tissues in living people," said Clark Spencer Larsen, an anthropologist at Ohio State University in Columbus, who was not part of the excavation.