Make a more or less subtle carve (depending on what you aim for) to make the chin stand out, as it is it seems the chin is coming up to the teeth. Also from the profile view, I'd say your nose cavity is too deep, and the angle of the jaw a bit to angled up (square it a bit more)
Also accentuate the relief (carve in) of the zygomatic arch
and maybe add a little bit of an indication of the temporal lines
And depending of what you aim for, you might want to look at the angle from the nose to the chin, which may very well be to much forward.
Now the jaw is too square, try to find a happy middle compared to your first one and this one and you should be in better shape. From the front view, I'd say your eyes socket a dropping too low on the exterior lower corner and maybe not low enough, on the interior lower one, also it seems that we see too much of the teeth, considering that there is a plane change from front to side plane, around the canine.
I would also make the zygomatic bone slightly more angular and thinner in the arch.
Here is a quick and dirty liquify and lines paintover to show you what I meant
Have not been on here for a while, but I now have tons more time for ZBrush. I am currently working on a Red Skull sculpt. Some references coming from the movie version.