A frenectomy is a relatively common procedure to release the frenum. This is a band of tissue connecting the tongue to the floor of the mouth, or which connects your upper lip to your upper gums or your lower lip to your lower gums.
If you take a look in the mirror, you will see these bands of tissue quite easily.
If the frenum is too tight then it restricts the movement of your tongue or lips, creating problems with speech and possibly with tooth alignment.
A frenectomy is a small procedure to release this band of tissue, allowing free movement.