In the UK they are often left to heal on their own. However, I met one guy who had his jaw wired in place because of a bad break (landed face first on the road after going over the handle bars on his bike at speed.........he weighed about 280lb too)......he was on fluids only for a while
If the jaw is not reset and healed correctly, it will keep popping out and causing a lot of problems down the line. Id go to a specialist, and let them decide on the best treatment. But normally they wire it shut for a while, inless its a serious or compund fracture then things get real tricky with surgical options etc...