Translation guide
The English word "teeth" refers to the hard structures in the mouth used for biting and chewing. In Japanese, the most common word is 歯 (は), but there are also specific terms for baby teeth, wisdom teeth, and related expressions.
歯
teeth
The hard, white structures in the mouth used for biting and chewing.
The standard word for 'tooth' or 'teeth'. Japanese does not usually distinguish singular and plural; context determines the number.
毎日歯を磨きます。
I brush my teeth every day.
歯が痛いです。
My tooth hurts.
The first set of teeth in children, which are later replaced by permanent teeth.
Literally 'milk teeth'. The standard term for baby teeth.
子供の乳歯が抜けました。
My child's baby tooth fell out.
The second set of teeth that replace baby teeth and are meant to last a lifetime.
Literally 'permanent teeth'. Used to distinguish from baby teeth.
永久歯が生えてきました。
Her permanent teeth are coming in.
The third molars that usually appear in late adolescence or early adulthood.
Literally 'unknown to parents', because they appear after one has left home. The common term for wisdom teeth.
親知らずを抜きました。
I had my wisdom teeth removed.
A more technical term for wisdom teeth, used in medical contexts.
智歯周囲炎になりました。
I got pericoronitis (inflammation around a wisdom tooth).
A hole in a tooth caused by decay.
The habit of grinding or clenching the teeth, often during sleep.
The act of grinding one's teeth, often unconsciously.
夜中に歯ぎしりをしているそうです。
I'm told I grind my teeth at night.
The tool used for cleaning teeth, or the action of cleaning them.
Toothbrush. A loanword from English 'brush' combined with 歯 (tooth).
新しい歯ブラシを買いました。
I bought a new toothbrush.
To brush one's teeth. The standard verb phrase.
食後に歯を磨きます。
I brush my teeth after meals.
A paste used with a toothbrush to clean teeth.
Literally 'tooth polishing powder'. The common word for toothpaste.
歯磨き粉がなくなりました。
We ran out of toothpaste.
Paste-type toothpaste, as opposed to powder. Often used to specify the form.
Japanese nouns do not typically change form for plural. 歯 (は) can mean 'tooth' or 'teeth' depending on context. If you need to specify multiple teeth, you can use counters like 本 (ほん) for counting teeth, e.g., 歯が二本抜けた (I lost two teeth).
練り歯磨きのほうが好きです。
I prefer paste toothpaste.