not that this is totally honest... but if you say you got your shit busted in an attack... crime victims assistance will cover it, just donate money to their organization to cover your karma.
but on the legit side... if you are experiencing medical conditions OTHER than the deviated septum such as: sleep apnia, constant nosebleeds, trouble breathing during work or normal activities, etc. basically if it "interferes" with your daily life or work... then insurance should cover it. be sure to mention those things. also an ENT (ear nose and throat) specialist may be able to help you in this inquiry.
just a little worst case scenario warning... people who have surgery on their nose occasionally end up losing their water tight characteristic.
EDIT: oh and some mouth guards have a little slot for breathing.
May God have mercy upon my enemies, because I won't.
-George S. Patton