Black teeth? Not necessarily a sign of bad dental hygiene in Meiji Japan.

It was customary in ancient Japan for women to blacken their teeth with dye, as white teeth were considered ugly. This practice called Ohaguro, persisted until the late 1800’s.

The main ingredient was a smelly dark-brown colored liquid, made of an acetic acid called kanemizu. Dyeing was mainly done by married women, though occasionally men did it as well.

In the Meiji period, a rumor spread about a spirit killing young virgins. In an attempt to hide from this spirit, woman wanted to “disguise” themselves as married. One of the ways they did this was by dyeing their teeth.

This teeth-blackening process was labor intensive. First, in order for the surface of the teeth to hold the dye well, the rind of a pomegranate, or something similar, would be rubbed across the teeth. Once dry, the dye mixture provided a rich black lacquer coating. Unfortunately, it faded quickly and the process had to be repeated regularly to maintain a beautiful set of blackened teeth, so no respectable woman who cared about her appearance would go more than three days without applying the dye again.

A side effect of this fashion fad was that the die actually did prevent tooth decay.

This practice gradually died out after it was banned by the Japanese government on February 5th, 1870. In modern times ohaguro is still practiced among some minority groups in Southeast Asia.