I had a trachea shave and mandible contouring done at the same time.
The most painful part of the recovery was the throat irritation from the breathing tube. Other than that I was pretty messed up for a little while but I'd really just describe it as inescapable discomfort, not actual pain.
My surgery was a year ago tomorrow. My chin is still a bit numb and perhaps it always will be but I never notice it and it doesn't bother me.