I'm kicking myself for not noticing this earlier, but it's become very obvious as DS2's upper teeth have come in. He has a significant diastema (about 3mm) and the frenulum is thick and fleshy and seems part of his gum, almost. It rund between his teeth. He won't let me see behind his front teeth (is that even possible without a dental mirror?
) but it does blanch when you curl his upper lip up.
He's always had a slightly awkward latch and I often have to flip his top lip up for him, but he's thrived on breastfeeding and I've not had any significant nipple pain. Though now he has 4 top teeth, I do often get notches pressed into the sides of my nipples when he's not concentrating, which hurt. 
I've done some googling and have found that experts and HCPs are widely divided on what to do.
Obviously I don't want his adult teeth to come in with a large diastema too, as there are implications for speech and also, I think, for tooth placement, as the frenulum can pull teeth out of alignment as well as set the top two far apart. Some dentists think you should wait until the adult teeth come in and then do surgery to divide the tie. Others seem to think this is best done as fast as possible, in which case, we've missed the boat. 
Is there any way around a GA if the tie is snipped? From my reading, it looks like a slightly more involved procedure than tongue tie.
Any experiences with this? What should I be doing about it at this stage, if anything? I have a sinking feeling that if I take him to the GP, they will see he's thriving, that my nipples aren't falling off and say 'oh well, no problem then'. Should we go to the dentist instead?