Beware of Optical Illusion of the Alar Base in Unilateral Cleft Lip Nasal Deformity

BACKGROUND: It is generally accepted that the alar base on the cleft side in the cleft lip nose is displaced outward and downward; therefore, it is rotated inward and upward in almost all procedures for cleft lip closure. However, nostril narrowing and collapse of the lower lateral cartilage on the cleft side are sometimes experienced. In this retrospective study, we investigated whether the preoperative alar base on the cleft side is displaced outward and downward. METHODS: This was a retrospective evaluation using preoperative frontal images obtained from patients with unilateral cleft lip (n = 245). The midcolumellar and subalare points were placed, and each ratio was analyzed and compared to those of age-matched controls (n = 40). RESULTS: The subalare on the noncleft side and subnasale were displaced upward and outward. In contrast, the subalare on the cleft side was displaced downward and inward. The displacement of the subalare was greater on the noncleft than on the cleft side. There were no significant differences between male and female patients and between the left and right sides. Among the complete cleft lip and palate, incomplete cleft lip and palate, complete cleft lip and alveolus, incomplete cleft lip and alveolus, and microform cleft lip groups, the complete cleft lip and palate group showed the greatest displacement. CONCLUSION: The cleft alar base appeared to shift outward and downward because of an optical illusion, but in fact, both alar bases shifted; the alar base on the cleft side was displaced inward and downward, and the alar base on the noncleft side was displaced outward and upward.