Excellent article on the difference between a normal frenulum and a lip tie

http://www.drghaheri.com/blog/2014/10/8/the-difference-between-a-lip-tie-and-a-normal-frenulum

Another great tongue tie read

http://www.drghaheri.com/blog/2014/3/22/rethinking-tongue-tie-anatomy-anterior-vs-posterior-is-irrelevant

Lip tie resource

Another great resource for lip ties: 

http://blog.babygizmo.com/2013/03/discovering-and-correcting-lip-tie-on-a-toddler-and-an-infant/