My son now 17 1/2 was also a permanent thumb sucker! We nursed, but his thumb was his best friend, as mine was for me when I was a child. Our Ped. said to tape a toilet paper roll around his arm when his was a baby. He wouldn't be to reach his thumb and consequently would stop sucking in a short period of time. My husband & I thought wow, that seemed cruel, plus it soothed him when he was upset and he stopped screaming. Well,in hindsight, at 4yrs Korey was still sucking his thumb. We talked about it, we read books, we tried rewards for not sucking. By the end of elementary going into middle school it was night habit only pretty much, but the permanent teeth were already in need of braces. I guess it was middle of 6th or 7th grade, it was time-Orthodontist, appliance, braces and retainer. The appliance was painful, degrading made him talk funny, but it sure broke the habit! If there is anything you can do and I have no idea what you can do, but if it doesn't physically hurt the child I'd try it! you'll save a ton of money and belly aching later. Good Luck. The sooner you can accept that kids will cry and try to get their own way anyway, just be strong & do what is best for them despite what they may want. You'll all be better for it! Good Luck again! J.