Elliott has a very genuine smile, which is one of the things I like about him. There is no artifice there -- he is what he is. Seeing his teeth doesn't bother me a bit -- my mother had those same "jumbley" teeth so I guess I'm used to seeing that.
Someone here made a comment earlier that just a couple of hours in a dentist's chair would fix Elliott's teeth. I think that's optimistic, to say the least. I got a good look at them last night when he hit a high note, and that looks like a job for braces. But if I were advising him, I would tell Elliott NOT to make any big changes to his teeth unless he finds them painful, or an orthodontist advises him to to avoid trouble down the line. (Those jumbley teeth can continue shifting throughout life, causing various problems.) The sound that is produced by a singer is an extremely individual thing, and the bones in the face, jaw, etc. enter into it (as well as a host of other things).
I read somewhere that he used to have allergies. Looking at him, he still has the telltale shadows under his eyes of someone who has nasal allergy issues. (That's the first thing an allegist looks for when you walk into his office -- are there visible shadows under the eyes?) Therefore I am guessing that Elliott still has allergies. Now THAT is something he should address as soon as he can, with the very best allergist he can locate. (As a matter of fact, he could do it right now and it would only increase his chances of success in this contest.) If he can get his sinuses completely clear, it will really increase that lovely ringing tone in his upper voice, and reduce vocal fatigue in general. Getting allergies under control is one of the most important things a vocalist can do. Much more important than what your teeth look like! :)
By the way, here's a site that someone put together for him: Click
Hm, I'm going to amend what I just said about Elliott's seeing an allergist *during* the contest. Some medications used for allergies can cause dry mouth and dry throat, which is NOT a good thing for singers. So Elliott should see an allergist who specializes in singers. (There used to be an excellent one in Fort Worth who saw virtually every singer in that area, but unfortunately he decided to run for Congress -- a loss of a good allergist! LOL!) Anyway, if you ask around amongst pro singers you can find an allergist who is aware of singing issues and used to dealing with them. That's the guy/gal you want to go to.