ObjectiveThis study aimed to explore the relationship between alveolar cleft and secondary nasal deformity post unilateral cleft lip repair in adults.MethodsA total of 27 patients aged 16-30 years old with unilateral secondary nasal deformity and alveolar cleft were included, 13 of whom underwent bone grafting. Spiral CT data of all preoperative and postoperative patients who had alveolar bone grafting were collected. Then, Mimics software was used for three-dimensional reconstruction to evaluate the correlation between the width, height, and volume of the alveolar cleft and those of the nasal deformity. The difference in nasal deformity before and after alveolar bone grafting was also explored.ResultsThe width of the alveolar cleft was positively correlated with the difference in bilateral nostril floor width (P<0 .05). as the effective depth of the alveolar cleft increased, the sub-alare inclination angle largened (P<0 .05). however, no significant difference was found in the nasal deformity between before and after alveolar bone grafting.ConclusionAlveolar cleft is closely related to secondary nasal deformities post unilateral cleft lip repair, especially nasal floor deformities. Alveolar bone grafting benefits adult patients for the improvement of secondary nasal deformities post unilateral cleft lip repair.