M.M.
Hi. My sister sucked her thumb for a really long time. I think she was in 2nd grade when finally the dentist put a retainer like in her mouth but it had 2 prongs that came down. The prongs didnt bother anything she could still eat & talk but she couldn't put her thumb in her mouth. Her teeth were really bad. Her 2 front teeth stuck straight out of her mouth. She looks great now & you would never know. I know this is extreme advice but this is what worked finally for my sister. I'm trying to stop the pacifier with my girl & I don't pay any attention to her until she takes it out. That's working to some degree.