cheekbones protrude somewhat, creating a bump, rather than a smooth surface as you're drawing it.
red is the shape
blue is the shading line/direction
green is the random crease that should be there because of his smile/smirk
very general and rough sketch, but you can see what i mean well enough
correcting it will make the jaw and face look more separate, like they should be, looks very much like the jaw and skull are one piece atm
also noticed he has a very angry looking brow section, but its not carried through to the eyes, angry eyebrows, amused eyes and mouth