To compare the upper airway dimensions between patients with non-syndromic cleft lip and palate (NSCLP) and skeletal class I control group using three-dimensional imaging.

Using a retrospective cohort study, the investigators enrolled a sample of patients from the Orthodontic Department of the Affiliated Stomatological Hospital of Nanjing Medical University during 2014 and 2018. The primary predictor variable was dentofacial skeleton (NSCLP vs. skeletal class I). The main outcome was three-dimensional upper airway morphology, which included volume, minimum cross-sectional area, height, and symmetry. Appropriate statistics were computed using P < 0.05 as statistical significance.

The study included 51 NSCLP patients and 53 class I controls, with comparable age and gender distribution. Three-dimensional analysis revealed significant morphological differences: compared to the class I group, NSCLP patients exhibited a larger nasopharyngeal volume ( p < 0.01) and a larger minimum cross-sectional area in the nasopharynx ( p < 0.05) and palatopharynx ( p < 0.01), but a reduced height of the upper airway ( p < 0.05) and palatopharyngeal airway ( p < 0.01). Furthermore, in unilateral NSCLP patients, the transverse diameters of the nasopharynx and palatopharynx were significantly smaller on the affected side compared to the normal side ( p < 0.05). While bilateral NSCLP and class I groups demonstrated symmetry at the nasopharyngeal and palatopharyngeal levels, both exhibited significant asymmetry at the glossopharyngeal segment ( p < 0.05).

Our findings conclusively define the specific three-dimensional differences in the NSCLP upper airway, which include an enlarged yet foreshortened nasopharynx and consistent lateral asymmetries. These structural nuances must be considered in the interdisciplinary management of cleft lip and palate to optimize functional and structural results.