If you've fractured your lower jaw, it will have occurred in one of three places: where the lower jaw joins the upper jaw and facial bones; near the angle of the jaw; or in a vertical line between the teeth.
When the opposing segments of jaw are brought close enough together, bones heal quickly. New bone is actually generated between the two segments and the bond can be stronger than before the trauma.
We "wire" the jaws for the rest of your recovery. Also, the splinting of the teeth helps keep the jaws properly opposed. Healing takes about six weeks, during which time the wire remains in place. You'll be limited to a liquid diet and perhaps less animated conversation.
It's a good time to read that big novel and relax; let nature take its course.