>>Baby is 7 weeks old and is going for a frenotomy for the lingual frenulum.
His labial frenulum is prominent and he can't flare his upper lip.  We
aren't sure if the sore nipples are due only to the lingual.<<

Yes these can cause problems; if it is uncomfortable for baby to flange the
lips, she will purse them more and may end up sliding down on the nipple,
not to mention possible nipple soreness. Haven't had one cut yet, though.

I just had baby #2 with restrictive lingual frenulum yesterday, four days
old and unable to latch on at all. He can stretch his tongue over his gums,
but when he opens wide and lifts his tongue, it makes that classic heart
shape. The breast just bounces off the bunched tongue every time..... of
course I've recommended a frenotomy, which mom is amenable to. At the same
time I noticed that both the upper and lower labial frenum were
questionable, but I don't know yet if they are truly an issue since we've
had no latch whatsoever. Baby is on nipple shield for the time being, and
struggling even there.

Lisa Marasco, BA, IBCLC