Some people have enlarged or excessively misaligned soft tissue attachments of either the lips or tongue.  This attachment from the upper or lower lips to the gingiva  adjacent to the teeth can cause gingival recession/gum disease of surrounding teeth.  It can also cause the teeth to form a gap (also known as a diastama) and become malaligned.  Removal of the frenulum or frenum can both prevent these pathologies as well as help to treat them if they already exist.  In the case of a lingual or tongue frenum it can cause a similar gum recession as well as restrict the tongue causing pain and or speech difficulties.  Removal of this frenum is also done to treat symptoms and pathology or prevent symptoms and disease.