If your little one wasn't diagnosed with tongue-tie until toddlerhood, did it look like this? I've taken him to the doctor but when she asked him to open his mouth he wouldn't (at 18 months old, what a surprise!) so she just shrugged and said they wouldn't do anything about it anyway. He has a couple of recognisable words but generally he's pretty indistinct, makes a sort of generic sound for 'What does the cow/sheep/chicken/cat say?' and he's always been very dribbly. It's hard to say what's normal for his age as of course there's a wide range, he's not yet 2, but I feel bad for him if something could be done and we're being palmed off.
There's a 'dip' in the end of his tongue like the top of a heart that's upside down. Dunno how to describe it, Anyway, my amazing artwork should help - what I would consider a normal tongue on the left, his tongue on the right.