I have (maybe had?) an overbite, so I was given retainers that would move my jaw forward. I've had them for almost a year now, but I don't wear them as much now because they scratch and make mouth ulcers (which is a big DO NOT WANT in Ramadhan). Though when Ramadhan is over, I'll wear them like usual, and it should be okay.
My mouth is also rather small, so they used those retainers to widen my top jaw (if that makes sense).
Also, my top right-most incisor is WAY back, so I have braces to fix that. Only recently started, though. I'm also sort-of expecting braces all along most of my teeth, because they are slightly out of place, but nothing too bad I guess.