1. What Did Blackened Teeth Mean in Edo-Period Japan?
In the Edo period (the era before 1868), a woman in Japan usually blackened her teeth when she married. The National Diet Library says that black does not take on any other color, so the custom seems to have been seen as a sign of faithfulness. [1] That is a later explanation of what people believed, not a rule anyone wrote down in one place, so it is safest to read it as "probably."
The first blackening was a small ceremony. A relative, often an older woman, acted as a kind of sponsor and could give the bride a full set of blackening tools as a gift and show her how to apply it. [1] Many women who were not married also did it as they got older, so as not to stand out, and courtesans and geisha sometimes wore it too. [1]
So the meaning was not the same in every time and place. A dictionary entry says it began among upper-class women in ancient times, that by the late Heian period (around the 1100s) men of the court and warrior class did it too, and that it later spread among ordinary people until it became the sign of a married woman in the Edo period. [4] Nobody knows for certain why the custom began. [5]
It also came with a change of face. Married women often shaved their eyebrows as well, which could make a face look quite different. The library notes that people of the time even wrote short poems about how much their looks changed. [1]
2. How Did People Turn Their Teeth Black?
Two materials were needed. One was fushiko, a powder made from dried galls (small swellings) that grow on the sumac-family tree called nurude. The other was kanemizu, "iron water," a liquid made by letting things like rice-washing water, vinegar, tea, sake, and scraps of old iron ferment together. The library says it smelled terrible. [1]
A dictionary entry that reproduces Wikipedia's description gives the steps. The brownish iron liquid, which is iron dissolved in acid, was brushed onto the teeth with a toothpick, and the tannin-rich gall powder was put on top. [4] Tannin is the same kind of substance that makes strong tea taste dry, and iron and tannin together are reported to form a black, water-resistant coating. [4] That is also how classic iron-gall ink works, so it makes sense to picture the teeth as being "inked." The same entry says the coating had to be renewed every day or every few days, which helps explain why the custom took time and money. [4]
Was it good or bad for teeth? The answer is mixed. The library says that today the dye is thought to have tightened the gums and strengthened the enamel, helping against gum disease and cavities, but that the strong acid in the base coat probably damaged the tooth surface. [1] It is better to say "it may have helped in some ways" than "it protected teeth."
3. Why Did Japan's Government Want Blackened Teeth to Stop?
After Japan opened to the outside world in the 1850s and 1860s, foreign visitors arrived, and many found blackened teeth and shaved eyebrows strange, even frightening. [2][3] The new Meiji government (it came to power in 1868) wanted to be taken seriously by other countries and was eager to adopt Western customs. So it tried to retire the practice. [2][3]
The steps came in two stages. In February 1870 the government banned blackened teeth and high-drawn eyebrows for the kazoku, the new class of nobles. [3] In 1873 the court announced that the empress dowager and the empress had given up eyebrow-drawing and blackened teeth. [2] (One library page words this announcement slightly differently, naming the emperor and empress. [3] Either way, it was a signal from the very top of society.)
Notice who the 1870 rule was aimed at: nobles. The library pages describe the ban for nobles and the court's announcement, but do not mention a law requiring ordinary women to stop. [3] That already hints at the answer to our question.
4. Why Did Ordinary Women Keep Blackening Their Teeth After the Empress Stopped?
The National Diet Library explains that ordinary people had hardly ever seen a foreigner, and black teeth were just part of everyday life, so being told they looked odd made little sense to them. [2] Around the middle of the Meiji period, a ready-made powder that turned black when dissolved in water was still on sale. [2] Its continued sale suggests that some people still wanted to blacken their teeth. (The Meiji period lasted from 1868 to 1912, so "the middle" means roughly the 1880s and 1890s.)
The color print from about 1877, four years after the announcement, is one example. It shows a woman whose teeth are painted black. [2] One picture cannot show what all of Japan was doing. It does show that the message from the palace had not reached everyone's mirror.
Then why did the custom disappear at all? The Wikipedia-based dictionary text reports that the bad smell, the effort, and the way it could make a woman look older put off young women. [4] So inconvenience and appearance may have helped the custom fade; these sources do not establish a single main cause. When it vanished depends on where you look. According to the same text, it was nearly gone by the Taisho era (1912 to 1926), while in some regions, such as parts of northern Japan, it lingered into the early Showa era (from 1926). [4] Because this comes from an encyclopedia entry rather than a study, a safe summary is: it shrank gradually from the Meiji period into the early 1900s.
5. How Can You Spot Blackened Teeth in Old Pictures?
You can go looking for ohaguro yourself. Search a library or museum collection for Edo and Meiji prints of women, and look closely at their mouths. Which women have black teeth, and which do not? Check the date on each print. Perhaps you will find another picture, made after 1873, that still shows black teeth.
Here is another detail to look for. The library says that in Edo prints, married women under thirty were often drawn with eyebrows even though real married women of that time had shaved theirs, because artists felt a face looked older without them. [1] So a print can be a mix of what people did and what the artist thought looked right. If you want to read more, the National Diet Library's online exhibition on Japanese makeup is written in Japanese, with many pictures. [1][2]