Until the early 20th-century Japanese aristocrats painted teeth in black color Bashny.Net

The practice of blackening the teeth of iron acetate ("ohaguro") was distributed in Japan since ancient times to the 1900s. Dye not only gave a smile, "beauty", but also well protected from damage teeth. Married women of teeth blackening resistance compared with loyalty and affection in a marriage.

Why did the Japanese do it? Just because the black color was (and is) in the Land of the Rising Sun is very beautiful. The black fabric, black paint, black hair, black teeth. In some parts of Southeast Asia ohaguro still practiced.

via factroom.ru