Effects of maxillary distraction osteogenesis on the upper-airway size and nasal resistance in subjects with cleft lip and palate

OBJECTIVES: To investigate the short- and long-term effects of maxillary distraction osteogenesis (DOG) on the upper-airway size and nasal resistance in nine patients with cleft lip and palate (CLP). STUDY DESIGN: Changes in the upper-airway size were measured by using lateral cephalometric radiographs taken immediately before and after DOG, and 1 year later. Nasal resistance was measured with a rhinomanometer. An analysis of variance was used to establish statistical significance. Spearman correlation coefficient was used to evaluate the relationship between changes in the cross-sectional area of the upper airway and nasal resistance in association with DOG. RESULTS: Immediately after DOG, the anteroposterior dimension of the superior part of the upper airway was significantly increased (p < 0.01) and nasal resistance was significantly decreased (p < 0.05). Moreover, the cross-sectional area of the total upper airway was significantly increased (p < 0.01). There was a significant correlation between the increase in the upper-airway cross-sectional area and the reduction in nasal resistance (p < 0.05). The upper-airway size was significantly augmented (p < 0.05) and nasal resistance was significantly reduced (p < 0.05) at 1 year after DOG compared with immediately before DOG. CONCLUSION: An increase in the upper-airway size and a reduction in nasal resistance occurred after maxillary DOG in patients with CLP, and these changes were stable after 1 year.