"Boli mnie ząb."

Translation: My tooth hurts.

[Mandiras]

Which case is mnie in here?

[Jellei]

"boleć" takes Accusative for the person who has the pain.

[Andrius5225]

I have a toothache.

[Jellei]

It's not only accepted, but even starred, actually.

[rommster]

I don't understand the structure of this sentence. (hurts me tooth?) Can't we say: "Mój ząb boli"?

[Jellei]

You'd be understood, but that's just rather not what a Polish person would say. Well, maybe a child. If you're in pain because of pain in some body part, we consider it something that 'happens to you'. And well, that's just the construction we use.

I googled "Mój ząb boli" and I got five results. I actually expected more.

[Vst321]

My tooth is paining?

[alik1989]

Such a wording is considered incorrect in both British and American English. Unfortunately, we can't accept all regional varieties as is might mislead EFL-learners into using such constructions outside their regional context.

[Alla_Fakaro]

The tooth CANNOT HURT!!! IT ACHES! Therefore, I have a toothache OR my tooth aches!

[alik1989]

Well, that's not what the iweb corpus says. Both your suggestions are already accepted, btw.