You can definitely get them to straighten the teeth, but I wonder about the underbite thing. I mean, to an extent, this is cosmetic surgery. You can go into a plastic surgeon's office and ask for specific changes to your nose or chin to whatever you think looks better. You would think this would be the same, as long as it doesn't ruin your bite.
I say it's worth a try. You'll probably need to try a couple different orthos.
