Dear Teachers,

1. If you dare touch any of her hair again, I will break all of your teeth so that you can not eat rice anymore.

- Is this natural to say?

Thanks very much to Teachers,

Well, Stevenukd, I'm not sure that many people would consider the message in your sentence natural or desirable, but grammatically it's OK. Emotion: surprise

We usually spell 'cannot' as one word.
>a world of hurt

I like that, GGEmotion: smile
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Here is perhaps a more normal sounding rewrite:

If you so much as dare to touch a single hair on her head, I will inflict a world of hurt upon you.

("I will break your teeth" just sounds odd, and "so that you cannot eat rice anymore" just sounds like a silly addition.)
 Marius Hancu's reply was promoted to an answer.
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I like the line from Pulp Fiction even better: I'm going to get medieval on your ***

<typo fixed>
Yes, that too ... get medieval on (you typed too fast:-)