Correlation between severity of sleep apnea and upper airway morphology: Cephalometry and MD-CT study during awake and sleep states.
CONCLUSIONS
The data show that the evaluation of obstruction site in patients with obstructive sleep apnea (OSA) should be performed in the sleep state rather than in wakefulness.


OBJECTIVE
The aim of this study was to identify correlation between severity of OSA as measured by the apnea-hypopnea index (AHI) and upper airway morphology examined by cephalometry and dynamic multidetector computed tomography (MD-CT) in awake and sleep states.


METHODS
Polysomnography and cephalometry were performed in 94 patients with snoring or OSA. Among them, 64 patients underwent MD-CT study. Thirteen cephalometric variables were measured. We analyzed the correlations between AHI and MD-CT measurements - minimal cross-sectional area (mCSA) and collapsibility index (CI) in high retropalate (HRP), low retropalate (LRP), high retroglossal (HRG), and low retroglossal (LRG) areas.


RESULTS
Statistically significant correlations between the AHI and inferior displacement of the hyoid bone and pharyngeal length were identified in the cephalometric study. In wakefulness, AHI had a negative correlation with mCSA in the LRP area and a significant correlation with CI in LRP and HRG in MD-CT measurements. However, in the sleep state, the AHI had a negative correlation with mCSA in LRP, HRG, and LRG areas and a meaningful correlation with CI for the whole upper airway (HRP, LRP, HRG, and LRG).
Heo
Jun-Young
JY
Department of Otorhinolaryngology-Head & Neck Surgery, Kyungpook National University, Daegu, Korea.
Kim
Jung-Soo
JS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000402:Airway Obstruction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002508:Cephalometry; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx / Q000000981:diagnostic imaging*; D017286:Polysomnography; D012123:Pulmonary Ventilation / Q000502:physiology; D012189:Retrospective Studies; D012890:Sleep / Q000502:physiology*; D020181:Sleep Apnea, Obstructive / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012913:Snoring / Q000000981:diagnostic imaging / Q000503:physiopathology; D013223:Statistics as Topic; D036542:Tomography, Spiral Computed; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult