What is tongue tie? Everyone has a thin band of tissue under the tongue where it attaches to the floor of the mouth. This is known as the frenulum. If this band develops in such a way that it tethers the tongue down, preventing the tongue from moving normally, this is known as "tongue tie." Even when tongue tie does occur, with age the frenulum can stretch out, and this often causes no problems whatsoever.
What kinds of problems can this cause? When present, this occasionally causes feeding problems right after birth. If this is the case, it will need to be treated immediately. If the child is over a year old, tongue tie can cause troubles in producing certain sounds of speech if it is left untreated.
Treatment (frenuloplasty): A frenuloplasty is a quick, minimally painful surgery where the frenulum is cut in order to release the tethered tongue.
You can download this useful fact sheet regarding tongue tie.