I caught this fish with no upper lip on a popper. It was healthy otherwise. Lip didn't appear to be torn off, it was more like it was deformed. Never seen this before.

Nah, that lip was torn completely off on an aggressive hook set....... I've actually done it a time or 2, regrettably.

Hopefully it grows back.

 

I caught one that looked similar but one side of his head was gone too, nearly to the eye. I figure a osprey or another water bird did it. 

I don't think his mouth is growing back any time soon - no more than ours would

 

I caught a small bass (same fish 3 times in a year) missing the right side of it's mouth. Freaked me out. But he still owned that little area of the creek.