A frenum is a band of tissue that holds down or connects the lip, cheeks, or tongue. These bands connect the tongue to the floor of the mouth (the lingual frenum), and the lip to the gum in front of the teeth (the labial frenum).
Occasionally, a frenum may be thick, short, or improperly attached. When a frenum interferes with the normal alignment of teeth, or restricts the movement of the lips or tongue, it can be corrected with a simple surgery called a frenectomy. A frenectomy generally takes less than fifteen minutes and is ordinarily well tolerated by most patients.