In southern and south-eastern Asia and the Pacific, teeth were blackened or lacquered to keep them intact and healthy.
The history of oral hygiene is surprisingly interesting: prior to the creation of the modern toothbrush there were a wide range of tooth-cleaning methods, from frayed twigs (the “chew stick”) to soot or shell pastes rubbed on the teeth with a cloth. One widespread method was teeth blackening.
The basic process is simple: make a black dye out of iron compounds or dark resin, combine it with a plant base, then cover your teeth with it. Reapply when it fades, and you have a beautiful black smile. The dye acts as a kind of artificial enamel, sealing up the little pits and crevices and staving off cavities.
Teeth blackening was practiced widely in parts of China; India; Japan; southeast Asian countries such as Vietnam, Thailand, the Philippines, Myanmar, and Laos; the Pacific; and even in parts of South America. It wasn’t just a matter of dental hygiene, though. Black teeth were fashionable and served as a marker of culture and civilisation. European explorers did not see it that way (of course!) and the weight of colonialism has killed off this practice in many places.