The Concept of Unilateral Cleft Lip Repair.

Surgical treatment of unilateral cleft lip is a difficult procedure, partly because many anatomical variants exist. The cleft lip has no excess tissue; hence, tissue from the cleft side cannot reach the normal side, even if all white lip tissue from the cleft side is preserved. Therefore, a basic concept is necessary to perform surgery according to a patient's anatomical diversity. Herein, we describe the essential concepts of unilateral cleft lip surgery. Specifically, the surgeon can insert the Millard's rotation advancement flap, Onizuka's small triangular flap, and Noordhoff's vermilion triangular flap into the median lip. An incision of the white lip should be made at the margin of the cleft to maximize tissue preservation. The amount of rotation and advancement is determined by the degree to which the contracture (hypoplasia of the lip tissue) can be released, and the median lip can be brought down to a normal level.