What should I do about my son's thumb sucking?

My little boy is 22 months old and he has been sucking his thumb since before he was born (I have the sonogram pic to prove it!). I have recently noticed that his two front teeth are starting to protrude further than all the rest of his teeth. Not to mention that his thumb is all calloused and looks disgusting. Plus, he sucks it 24/7 and he doesn't talk. My dad is a dentist and all his friends are orthodontists and oral surgeons, and they said that if he doesn't stop he can actually change the bone structure of his palate and he will need all kinds of dental work to correct it. Has anyone experienced this with their children? I know that it's very comforting for him. My husband is always trying to pull his thumb out of his mouth, and my son gets very upset and starts to cry and runs away and hides to suck his thumb. Even when I check on him at night he is sucking his thumb. He doesn't care if his thumb tastes bad either. I would really like to hear your experiences and advise
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Most babies and young children tend to suck their thumbs. While you may be concerned about your child's habit, it is actually quite harmless. Here are a few facts about thumb sucking: http://www.greatdad.com/tertiary/89/1833…
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