What does "齓" mean?

Question

I've found this kanji during Shodo practice. My teacher (Japanese) didn't know the meaning (she recognized the Tooth bushu/radical but not the "word").

I tried to look it up on the electronic dictionaries I own, both Japanese and Chinese, but while the kanji exists and even has a phonetic associated to it:

there is no actual meaning.

Finally I got something from a Chinese online dictionary. Allegedly (I used Google translate on the whole page) it is an old ideogram for "Milk Teeth".

Now the question(s):

• Does this mean anything in Japanese?
• What would be the current Japanese way to indicate "Milk teeth"?

Answer 1

The character in question was originally composed of 歯 (teeth) and 巳 (child). It represented children's teeth. This later became 齔 and 齓. 齔 is typically preferred over 齓, so I will use it below. It has two primary meanings: 1) in children, the replacement of old teeth with new teeth; 2) children of an age in which they are loosing their old teeth and growing new ones.

There are several compounds:

• 髫齔 (chōshin): a child around the age of 7 or 8
• 齔髫 (shinchō): (in general) a child
• 齔童 (shindō): children of an age in which they are loosing their old teeth and growing in new ones

Answer 2

Kanjigen lists 齔{シン} (U+9F54) together with 齓{シン} (U+9F53), and as far as I can tell the former is more common, though I'm not sure either are commonly used (I think 乳歯{にゅうし} might be much more common to mean "baby tooth").

It says it can refer to:

1. (シンす) (verb/noun) The losing of teeth which occurs around the age of 7 or 8. Or, the teeth one has prior to having them replaced (乳歯{にゅうし}).
2. (noun) A child which is aged when one loses teeth.

It also links to a similar Kanji which means "baby teeth": 齠{チョウ} (U+9F60), though I'm not sure that's particularly common either.

Kanjidic also defines 齔 (U+9F54) as "losing baby teeth"/"child" and Unihan as "lose baby teeth and get adult teeth".

Answer 3

I cannot answer the first question, but deciduous/milk/baby teeth is [乳歯]{にゅうし}.

(Just a guess, but the reading かけば sounds like かけ + 歯(with rendaku), so I imagine it to be something like 欠け歯 but I cannot find anything to substantiate this claim.)