RÉSUMÉ
BACKGROUND: Although the "white skin roll" of the lip is often considered a line, it is better defined as the subunit between the vermilion border and the upper lip horizontal groove. In many unilateral cleft lip repair techniques, this structure is approximated between both sides of the cleft without restoration. This study aimed to analyze the white skin roll height in patients with unilateral cleft lip. METHODS: This retrospective cohort study included 134 consecutive infants with unilateral cleft lip aged 3-6 months who underwent lip repair in a single institution between January 2019 and July 2021. White skin roll heights at the peak of the Cupid's bow on the non-cleft side (CPHIR), cleft medial element (CPHIL), and cleft lateral element (CPHIL') were measured, and differences in their averages were analyzed. RESULTS: The mean height was 1.70 ± 0.30 mm at CPHIR, 0.98 ± 0.33 mm at CPHIL, and 1.28 ± 0.32 mm at CPHIL.' The mean difference in height between CPHIR-CPHIL, CPHIR-CPHIL,' and CPHIL-CPHIL' groups was significant for each paired sample (p < 0.01). No difference was found between the complete and incomplete clefts or left and right clefts (p > 0.01). CONCLUSIONS: A significantly reduced mean height of the white skin roll was present more markedly on the cleft medial element than on the cleft lateral element. Therefore, we strongly support using a white skin roll flap on the cleft lateral element for unilateral cleft lip repair, embracing the concepts of subunits and lip contour lines.