<jats:title>Abstract</jats:title><jats:sec><jats:title>Objectives</jats:title><jats:p>In recent years, many studies have reported that the presurgical nasoalveolar molding method improves the nose morphology; however, the reason for its effectiveness after surgery has never been understood. We evaluated the effect of nasoalveolar molding by comparing it with a passive orthopedic method without a nasal stent and focusing on the nostril morphology after primary cheiloplasty using various measurement methods. We then analyzed the essential factors.</jats:p></jats:sec><jats:sec><jats:title>Materials and methods</jats:title><jats:p>The patients involved were 31 infants with unilateral complete cleft lip and palate treated with primary cheiloplasty at the University of Tsukuba Hospital from 2004 to 2011. Of the 31 infants, 16 received nasoalveolar molding treatment and 15 received passive orthopedic treatment as controls. Photographic facial measurements were performed for all patients immediately and 7 months after primary cheiloplasty. The esthetics of the nostrils were assessed according to the left–right nostril symmetry, as measured by the Hausdorff distance, area ratio, perimeter ratio, and aspect a/u (the aspect ratio of the affected side)/(the aspect ratio of the unaffected side) ratio. In addition, the inclination of the nasal ridge was assessed using anthropometric measurements (Grc‐Grn∠midline and midline∠columellar axis).</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>The area ratio, perimeter ratio, and Grc‐Grn∠midline were significantly greater in the nasoalveolar molding group immediately after surgery (<jats:italic>p</jats:italic> = 0.00062, 0.016, and 0.048, respectively) than in the control group. However, the Hausdorff distance and aspect a/u ratio were more favorable (<jats:italic>p</jats:italic> = 0.0018 and 0.0039, respectively) in the nasoalveolar molding group after 7 months.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>The results of our study suggested that using nasoalveolar molding as a presurgical orthopedic treatment could improve the shape of the nasal cartilage with surgeon's corrections.</jats:p></jats:sec>