Tongue tie doesn't cause dumbness or affect speech except exceptionally thick one which doesn't allow the baby's tongue to lift which may rarely affect speech, in such cases qualified paediatric surgeons can do a simple surgery to free it. In fact this is done around age 1 to 2 years."

....In that case the mum doesn't need to worry or do anything. It recedes as the tongue grows longer and bigger.
Due to many mums complaints and anxiety over tongue-tie, many charlatans often offer to do the surgery and often create more problems for the baby including bleeding, infections e.t.c. Please make sure only the professionals see your baby and if the doctors say don't worry, don't go behind to meet charlatans to do it. Some hospitals also take undue advantage of some unsuspecting mums by doing the surgery unnecessarily just to make money off them.

There is what we call frenulum which attaches the tongue to the floor of the mouth. It is usually a thin membrane and as the baby's tongue grow bigger, it seems to become smaller. However, in some babies, it can be quite thick. It is this frenulum mum usually call tongue-tie especially when it extends to the tip of the tongue. Most times, the baby's tongue can still lift up and protrude without any problem