Wow, I have
so many questions.
Does it drool?
What happens when you chew?
What happens when you drink water?
Why is the cheek so puffy, is the hole infected?
The cheek is largely muscle, can the jaw even move correctly any more?
Though, to be fair, I'm pretty sure that it's CG. The left image looks like he's puffing his cheek out with air, which should be really hard, or even impossible, with a giant hole in it. There is also a vast difference in the amount of skin visible between the lest and right images within the hole. Lastly, the angle of the tongue in the right image seems implausible, especially since its center-line doesn't curve back towards the throat but rather appears to be perpendicular to the palate and hole.