u/Effective_Fig5192

I'm working on a visual novel, and I'm trying to work on my shading. Something doesn't sit quite right with it, and I can't put my finger on it.
I also never realised before just how complicated teeth are - it's not quite as simple as fill>off white>click between the lips.
I'd appreciate any advice or critiques that can help me improve, on any aspect of the drawing, not just what I mentioned. Thanks!