A new method to quantify subtle morphological deformities in nasal profile curvatures and its application for analysis of unilateral cleft lip noses

Objective: The authors conducted the present study to elucidate what elements characterize the nasal profiles of patients with unilateral cleft lips (CLs). Materials and methods: A total of 40 Japanese unilateral CL patients were studied. For each patient, the nasal profile curve was traced on three-dimensional computer tomography image. Then four points were marked on the contour. The points were NAS (Nasion), MAP (the Most Anterior Point on the nasal profile curve), GPRN (the Genuine Pronasale: the point on the nasal curve at which the curve protrudes most), and SBN (Subnasale: the point at the columellar base). Using specially designed software, the distances between these marking points were measured along the nasal profile curve. Results: In CL patients, the distance between the MAP and GPRN is longer, and the GPRN is located more inferiorly than in non-cleft persons. Conclusion: The nasal tip tends to become round and to droop in unilateral CL patients. In order to avoid this deformity pattern, the nasal tip should be reshaped to present a sharper curvature and corrected superiorly.