What is it that makes your jaw ache when you’re eating?

When if you're chewing something like chewing gum and you chew too hard, sometimes you can overwork the muscles and they can ache in the same way as if you did a lot of digging you might make your back or shoulders ache. The other thing to consider is that there is a joint where the mandible, or jaw meets the skull, called the temporomanibular joint. That can actually end up being sore in some people, and then its called TMJ dysfunction.