Objective: To three-dimensionally (3D) analyze the maxillary morphology of infants with unilateral cleft lip and palate (UCLP) and preliminarily classify the alveolar arch to assist in personalization of sequence therapy.
Design: Retrospective study.
Setting: Patients with UCLP referred to outpatients' clinic.
Participants: 84 nonsyndromic infants with complete UCLP were recruited (58 boys, 26 girls, mean age 29.48 days).
Main outcome measure: Morphometric analysis was conducted on 3D maxillary models. Principal component analysis (PCA) and cluster analysis were combined to classify maxillary phenotypes preliminarily. The Wilcoxon Signed Rank test and the Kruskal-Wallis test were used to compare differences between variables. A P value less than .05 was considered statistically significant.
Results: The maxilla was divided into three types: narrow, homogenous and broad, accounting for 9.52%, 23.81% and 66.67% respectively. The alveolar cleft site (median value) was located in 61% of the total length of the alveolar arch. In the comparison of anterior and total alveolar lengths, the non-cleft side had longer alveolar bone than the affected side, a difference of approximately 2 mm. Pairwise comparisons of variables describing alveolar symmetry revealed significant differences in all subjects; whereas type C had poorer arch symmetry than types A and B, mainly in terms of anterior and overall symmetry.
Conclusions: In infants with UCLP, the maxillary alveolar arch was inherently asymmetrical with partially bone missing (about 2 mm). Significant differences in alveolar bone morphology and symmetry exist between different types of infants, with individuals with broad clefts (type C, the largest proportion) having the worst maxillary development.
Keywords: cleft lip and palate; development; infant orthopedics; maxilla; nonsyndromic clefting; skeletal morphology.