A frenum is a naturally occurring small fold of tissue that holds and sometimes restricts the movement of tissues (such as the lip, cheek or tongue) in the mouth. It is part of the normal oral anatomy, which usually blends into the gum well away from the teeth. However, in some cases the frenum attachment can occur close to teeth and appear to push them apart which leaves a gap. This is often seen between the upper front teeth.

In some cases, the frenum may exaggerate the pull on the gum margin and can result in gum recession.

A frenectomy is a common and simple periodontal procedure performed in children and adults whereby a tight frenum may be relieved to allow spontaneous closure of the space between teeth or aid with orthodontic closure of the gap. The timing of when to perform the procedure may vary from patient to patient. In order to enhance the success of the result, it is important to have this assessed prior to considering this treatment.