The use of the nasoalveolar molding technique (NAM) aims to reduce passively the width of the alveolar gap, while improving the AP discrepancy but also focusing on the nose. We developed a within-subjects study in which 11 infants with unilateral lip deformity and varying degrees of alveolar gaps were treated by NAM. Patients included in the study presented alveolar gap at the first appointment to configure the molding device. Alveolar gap was then measured again at the time of lip repair to evaluate the impact of the appliance utilization, and the nostril shape was reassessed to verify the benefit relative to nose symmetry. All patients obtained significant reduction of the alveolar gap. The appliance also facilitated primary nasal positioning, significantly improving nasal symmetry and nostril shape. NAM constitutes an important adjunct to ameliorate the results of primary definitive lip repair while also improving the surgeon's ability to provide nasal symmetry.