I don't know, I would think it would depend on the break and the severity. They told Ali his jaw would heal back stronger, he never had another problem with it but the guy I knew got some teeth knocked out of place in the UFC and from there on, he had issues around his jaw, I think his Jaw was broken at least twice.
Jake supposedly has a break in two places and my own personal theory is that anyone who hasn't taken punches regularly since childhood will have the same resilience in their cranial bones as a long term fighter. You know how it takes time to condition shins for muay thai? and even then people shatter their shins? well, I think all parts of the body have a way of toughening up to an extent. George Benton even said the skin and facial tissue gets used to getting hit in training to the point where the guys don't swell up as much. However, each individual has different resistance to cuts, breaks and injury. Some guys are known as bleeders and there isn't anything that can be done about that. Jack Dempsey was said to soak his face and hands in brine so he wouldn't cut but if that really worked, lots of bleeders would have done the same thing after him.
