A frenectomy is the surgical removal of the frenulum or frenum, which is a thin band of tissue found in various parts of the body. This surgery is most often performed on frenum tissue that is found in the mouth. It is a common surgical procedure in dental practices. 

There are two primary locations in the mouth where frenum is found — under the tongue and underneath the center of the upper lip. The frenum attaches the muscles of the cheeks and lips to the mouth; in some cases, however, this tissue may interfere with the development of the mouth.

A lingual frenectomy is the removal of the lingual frenum, or the tissue under the tongue. In some cases, if the tissue is attached too closely to the tip of the tongue, it can interfere with speech and proper tooth development. After the procedure, the tongue can usually be completely extended and becomes fully mobile.