My grandson, just eight, had most of the symptoms you described. He was breast fed, then sucked his thumb after weaning. He was always a mouth breather, hence this seemingly unquenching thirst. About a year ago my daughter noticed his bite was different, lower teeth behind the top teeth, went to a dentist and he said the tonsils and adenoids had to come out first, then treat the jaw. He had the surgery, great results, has had some treatments from the dentist, may not have to have the extensive "bracing" on his teeth, his breathing is normal, and he's a different kid. E-mail me if you want more particulars and I'll give you my daughter's e-mail, she can give you more details.