My 8 year old son sucked on his finger for about 3-4 years (after sucking on a pacifier before that!) and now his teeth are all pulling in one direction. The orthodontist we have been seeing wants to remove 1 baby tooth from the other side of the mouth, with the idea that the gap will hopefully cause the teeth to start to shift back over that direction.
It sounds like it makes some sense, I guess, I just hate the idea of pulling out a live healthy tooth! But it is a baby tooth, so maybe it's not such a big deal?