An extra fold of tissue hangs down from the left upper lip. (from Color Atlas of Oral and Maxillofacial Diseases)
Double lip is an uncommon oral anomaly in which there is an excess fold of tissue along the mucosal surface of the lip. It either may be congenital or develop later in life. The upper lip is affected more frequently than the lower lip, although sometimes both lips are involved. The redundant tissue may be seen bilaterally in a symmetric fashion, or it may appear primarily on one side. When the lips are at rest, a double lip may not be noticeable; however, when the patient smiles, the excess tissue will become evident. Double lip occasionally may be a component of Ascher syndrome, which is characterized by the following triad: (1) double lip, (2) blepharochalasis (edema and sagging of the upper eyelid), and (3) nontoxic thyroid enlargement.
No treatment may be required for mild forms of double lip. However, more severe examples can be managed by surgical excision of the excess tissue for cosmetic purposes.