Anatomy of a cat's tumor

I'm visual, so here's a diagram to explain what's happening...

PURPLE = the area of the tumor. Most of it is in the cheek and is gradually spreading towards the right side of this diagram, where the jaw and eye are.
PURPLE X's = teeth that have been extracted or loosened on their own. She may have lost some more upper teeth that we don't know about because when the vet looked in her mouth today, she didn't see any teeth that would create any sort of grinding with the bottom teeth.
ORANGE = the jawbone that the tumor is rubbing against. You'll notice from the arrows that the wider her mouth is open, the greater these two areas come into contact.