Alar Asymmetry in Patients with Unilateral Cleft Lip: Implications for Secondary Rhinoplasty

Objective Alar asymmetry in unilateral cleft lip (UCL) nasal deformity is a well-recognized clinical feature. However, there is a lack of comprehensive quantitative analysis of this asymmetry. This study compares the shape, volume, and axis rotation between the cleft and non-cleft ala in skeletally mature patients with UCL. Design A retrospective comparative study utilizing three-dimensional rendered CT scans. Setting Tertiary care pediatric institution. Patients, Participants This study included 18 patients with UCL nasal deformity at skeletal maturity. Main Outcome Measure(s) Cleft and non-cleft side ala volume, surface area, and axis to the midsagittal plane. Results The cleft-side ala was significantly lesser in volume by 27.3%, significantly lesser in surface area by 17.6%, and significantly greater in surface area to volume ratio by 14.6% than the non-cleft ala. The cleft-side ala was significantly greater by 43.1% horizontal axis to the midsagittal plane. In patients with primary rhinoplasty, the cleft-side ala had 28.0% less volume and 18.7% less surface area. In intermediate rhinoplasty, the cleft-side ala had 39.1% less volume and 23.5% less surface area than the non-cleft ala. Conclusions Significant asymmetry exists between the cleft-side and non-cleft ala in patients with UCL. The cleft-side ala is significantly smaller in volume and surface area than the non-cleft ala. Additionally, the cleft-side ala demonstrates a significantly greater horizontal axis that contributes considerably to nasal asymmetry, supporting the need to restore a normal vertical axis to the clef-side ala.