Assessment of the effect of maxillary protraction appliance on pharyngeal airway dimensions in relation to changes in tongue posture

BACKGROUND: Literature is controversial in regard with alterations in pharyngeal airway dimensions subsequent to maxillary protraction. The correlation between maxillary protraction and sagittal airway dimension was investigated in association with tongue and soft palate position in skeletal Class III children. The results were compared with those of an untreated Class III and a Class I malocclusion control group. MATERIALS AND METHODS: In this cross-sectional study pre- and post-treatment cephalometric radiographs of 19 Class III patients (6 males, 13 females; mean age, 7.93 ± 0.96 years) treated with facemask were analyzed. The correlation between treatment changes in craniofacial morphology and those in the upper airway, tongue, and soft palate was evaluated. These results were compared with those of a group of 16 Class I malocclusion patients (1 male, 15 females; mean age, 7.31 ± 0.7 years) and a group of 15 untreated Class III patients (4 males and 11 females; mean age, 7.46 ± 0.1 years). A paired t-test, the Shapiro–Wilk test and Mann–Whitney U-test was used. The level of significance was established as P < 0.05. RESULTS: Nasopharyngeal airway measurements PNS-ad1 and PNS-ad2 significantly increased by 2 mm and 2.1 mm, respectively. Statistical analysis revealed that maxillary protraction had a positive relationship with PNS-ad1 and PNS-ad2. CONCLUSION: Nasopharyngeal airway dimensions can be improved in the short term with maxillary protraction in skeletal Class III children.