Resetting a heavily sculpted section of a model

Yoza! 

As per the question title, I was wondering if there is a way to 'reset' a heavily scultped section of a model. Y'know, a section that's got a whole shebang of curves, inflations, ups and downs etc on big & small scales.

I'll give an example with a screenshot below;

Let's say I finished my shark sculpture and looked back and wasn't too chuffed on the corner of its mouth. Keeping in mind that I probably sculpted the corner way back, far beyond the undo steps of hitting ctrl + z. 

Is it possible to reset, or remodel, that section so I could start over on it? I figure it wouldn't be quite possible to get it back to how it exactly was prior to sculpting it in the first place. But could I do anything, as if to wipe it clean, to get it to a point where it's a smoothish, vertex friendly surface to remodel?

While actually sculpting the corner, I did try to use various tools to flatten it out, but it resulted in a messy goop of lumps - So I reloaded a save and made do with what I had.

I hope this makes sense, I'd love any pointers!