Shitting teeth

exp.

Heard in Sligo

Part of a common threat, that you will punch a person in the mouth so hard that they will swallow their teeth.

In use

If you ever say that to me again I'll give ya such a slap I'll leave ya shittin' teeth!

Posh English

If you dare repeat such an insolent remark, I shall administer a buffet of such violence that you will masticate your own molars.