Typically their teeth won't bother them until there is a bit put in their mouth. The wolf teeth are sometimes bothered by the bit, some people ride with bits on horses with wolf teeth and they do just fine. I rode for a few years with a bit on my mare with her wolf teeth in, but I was a young easily influenced teen who believed what the horse people around me told me, and they said that the bit wouldn't bother the wolf teeth. I just don't like bits. To me, if a horse will go just as well or better bitless, why put them through the discomfort of a bit? You know when you go in for dental x-rays and they put that thing in your mouth and besides being uncomfortable (at least for me as I have a narrow mouth) and you can't help but salivate around it, but you can't swallow so it ends up just collecting and if in too long spilling out. That is what I imagine a bit to be like for a horse, and I can't imagine spending several hours like that. As the article stated, horses are nose breathers so IMO they should be able to move with their mouth closed.
This is all just opinion and personal beliefs and preference though. As I said, to each his own. My mother's horse rides in a bit and I'm not switching her until I have the time to retrain her (which actually the transition is not a big deal, I would just want to make sure she has the same amount of control).
A note about bitless: be careful what you use as some hackamores and bitless bridles can be just as severe as any bit. Sidepulls and bosals are very safe choices. I ride in an english short shank hackamore.
I do plan on getting her teeth checked. In the meantime I think I will do some research on a bosal hackamore.
I do like the natural horseman approach to training. You do have to have patience and it take longer but I feel that the results are longer lasting.
It will be a while before we even think about saddling up and going trail riding. Right now we are still learning each other.
How would I know she responds well to a hackamore without getting on her?