The Vikings

Archaeological evidence shows that some Viking men in Sweden, Denmark and England filed their teeth. This generally took the form of one or more often multiple horizontal grooves on their front teeth, though the precise shapes of these grooves and their depth varied. The front of the teeth appear to have been first flattened prior to the filing of grooves. These filings might then be fillled with pigmented material, though whether this was intended as pain relief or to make them more visible is unknown. 

Among those burials exhibiting evidence of tooth filing found in southern Sweden, the majority were from the island of Gotland off the coast of Sweden. There are some indications, based on analysis of grave goods, that those men who had filed teeth came from a different strata of society, though what group they might represent is unknown. Though evidence of teeth filing exists throughout the entire Viking age, most examples of this phemonema appear to be from individuals who died from the late 9th century to the 10th century CE.