BACKGROUND Adequate skin lengthening and symmetry may not be consistently obtained in unilateral cleft lip repair, especially in patients with complete cleft. The purpose of this study was to present the model of muscle dissection and approximation to facilitate lip lengthening and symmetry. METHODS The design followed the rotation-advancement (RA) method without skin measurement. A curvilinear skin incision was made from subnasale to the Cupid's bow peak (CBP). Muscle dissection was continued to the contralateral nostril floor beneath the columellar base to facilitate downward rotation in the medial lip. Wide muscle dissection was performed in the lateral lip segment from the nasal mucosa passing the alar base. The lateral lip muscle was advanced and sutured to the medial lip muscle in a Z-plasty fashion. A small skin backcut was made above the CBP. Primary nasal correction was performed. A series of 138 patients with complete unilateral cleft lip and palate were included in this study. Standard photographs were collected for measurement in the nasolabial region. RESULTS Adequate lengthening and symmetry of the lip was obtained. The ratio of vertical philtral height was 0.99±0.05 between the cleft and noncleft sides. The C flap was used for supplementary skin lengthening in 58% of cases. Postoperative lip retraction requiring massage occurred in 13%. Overall nasolabial appearance was satisfactory. CONCLUSIONS The new technique of perioral muscle reconstruction facilitated to obtain lip lengthening and symmetry in the repair of complete unilateral cleft lip.