Abstract: PURPOSE: To analyze whether upper airway dimensions were influenced by different sagittal skeletal pattern among adolescent patients. METHODS: Seventy-five adolescent patients were divided into 3 groups based on their ANB angles.The three groups were matched for age and sex. All subjects had a normodivergent skeletal pattern.Airway lengths, cross-sectional measurements and volumes were measured by using cone-beam computed tomography (CBCT) volume scans, and two-dimensional lateral cephalograms were created and analyzed. Airway lengths, cross-sectional measurements and volumes were compared among 3 groups. Statistical analysis was performed using SPSS 22.0 software package. RESULTS: No significant difference among the three groups was found in Anp, Lnp, Lvp, Lgp and Lhp cross-sectional areas of the airway. The glossopharynx volume was smaller in Class Ⅱ[(2.34±0.79)mLthan in Class Ⅲ[(3.18±0.63)mLpatients(P<0.05). Total upper airway volume in Class Ⅱ[(13.89±2.51)mLpatients was smaller than in Class Ⅰ[(16.48±4.41)mLand Ⅲ[(17.47±3.55)mLpatients(P<0.05). CONCLUSIONS: Upper airway volume is significantly reduced in Class Ⅱ sagittal skeletal pattern, leading to a higher risk of obstructive sleep apnea/hypopnea syndrome.

Key words: Sagittal skeletal pattern, Upper airway, Cone-beam CT