I think I'm going to re-join this thread. Just recently it's occurred to me that I'm not sure my son is as understandable to strangers as he should be. He's 3y2m, and his anterior TT is pretty clear, he has a heart-shaped tongue that doesn't extend out far at all. Looks just a bit worse than mine.
I'm not completely clear how you'd tell if a person has both, because the tightness in front is one reason you couldn't lift your tongue to the top of your mouth, and my daughter has a high, arched palate but she can touch the top of her mouth with her tongue.
Anyway, I think I'm going to make an appointment with our pediatrician to talk about his pronunciation, and then see if she knows anyone who clips TTs in older kids.
Pookietooth--I think clipping and CST can help at any age--it's supposed to take longer with older kids, I really don't know how long, but I think I may be going down this path with my 3yo sometime soon.