Because only bone is removed from the outside of the jaw and chin, giving it a female shape, the jaw will not be any weaker than a genetic female jaw and chin. It would take a really bad trauma to break it. So there is no need to worry. If the chin needs to be moved forward, the chin is separated from the jaw and fixed in place with screws. In that case, the jaw will be weaker in the midline for about 6 weeks. But the screw fixation is so strong that even in these cases, it would take a real trauma to break the jaw.