A frenum is a fold of tissue or muscle connecting the lips, cheek or tongue to the jawbone. The most common places to find frenums are at the midline between the front top teeth, the bottom front teeth or connecting the tongue to the lower jawbone. A frenectomy is the removal of one of these folds of tissue.
Sometimes a frenum can be attached too close to the teeth on the gums causing either recession or spaces between teeth. The frenectomy procedure involves the removal of the tissue attachment between the teeth. In cases where the two front teeth are apart prior to orthodontic closure, studies have shown that without a frenectomy procedure, there is a 70% incidence of the of the space reopening after the braces are removed.