Ohaguro (お歯黒?) is a custom of dyeing one's teeth black. It was most popular in Japan until the Meiji era. Tooth painting is also known and practiced in the southeastern parts of China, Pacific Islands and Southeast Asia. Dyeing is mainly done by married women, though occasionally men do it as well. It was also beneficial, as it prevented tooth decay, in a similar fashion to modern dental sealants.
In Japan, Ohaguro existed in one form or another for hundreds of years and was seen amongst the population as beautiful until the end of the Meiji period. Objects that were pitch black, such as glaze-like lacquer, were seen as beautiful.
The word "ohaguro" was a Japanese aristocratic term. There is an alternate reading for ohaguro, 鉄漿 (literally 'iron drink' "lead"). At the old Imperial palace in Kyoto, it was called fushimizu (五倍子水?). Among the civilians, such words as kanetsuke (鉄漿付け?), tsukegane (つけがね?) and hagurome (歯黒め?) were used.