G.W.
I hate to be the negative one here, but I was a thumb sucker from birth and no matter what my mom did (and believe me, she tried some SCARY things!!), I didn't completely stop until I was around 12 (I did it mostly in my sleep). Anyway, it did affect my teeth quite a bit but when I stopped, my teeth moved together perfectly without braces. I have friends whose kids are in that 6-9 range and still do it, too. They've pretty much concluded it will stop when their kids are ready. If you get good advice, let me know, I have 15 1/2 month old twin boys and they both are thumbsuckers - LOL. Have a blessed day!