[Upper airways and sleep apnea syndrome]

Area of Science:

• Otolaryngology
• Sleep Medicine
• Radiology

Background:

• Imaging techniques now allow detailed characterization of upper airway (UA) collapse during obstructive sleep apnea.
• Pharyngeal collapse, starting oropharyngeally and extending to the hypopharynx, is observed.
• Reduced pharyngeal caliber is noted in both snorers and apneic individuals.

Purpose of the Study:

• To describe the characteristics of pharyngeal collapse during obstructive and central sleep apnea using imaging.
• To identify imaging findings predictive of treatment outcomes for uvulopalatopharyngoplasty (UPPP).

Main Methods:

• Utilized imaging techniques to visualize upper airway (UA) collapse during sleep apnea.
• Performed cephalometry and computed tomography (CT) of the pharynx.
• Correlated specific cephalometric and CT measurements with UPPP outcomes.

Main Results:

• Observed active oropharyngeal collapse with soft palate and tongue movement, extending to the hypopharynx.
• Noted synchronous displacement of the hyoid bone and cervical spine with thoracoabdominal movements.
• Identified retrognathism (MP-H > 24 mm) and narrow pharyngeal airway space (PAS < 5 mm) on cephalometry as predictors of poor UPPP results.
• Macroglossia and reduced hypopharyngeal surface area on CT also correlated with poor UPPP outcomes.

Conclusions:

• Imaging reveals distinct patterns of pharyngeal collapse in sleep apnea but lacks specificity for diagnosis or severity assessment.
• Cephalometry and CT are valuable adjuncts, particularly when considering uvulopalatopharyngoplasty (UPPP).
• Specific cephalometric and CT findings can predict suboptimal outcomes following UPPP surgery.