DD2 has one but we took her to a paediatric dentist about a year or so ago and they told us not to do anything about hers and that it should correct itself over time. She's 2.5 yrs now and has proved a lot and doesn't seem to be causing her any issues. Brushing her teeth is a lot easier now too.

DD2 also had a tongue tie but that was snipped at around 7 weeks.