UPPER AIRWAY SHAPE - IS IT IMPORTANT IN THE PATHOGENESIS OF OBSTRUCTIVE SLEEP-APNEA

It is widely accepted that the size of the airway and the level of upp er airway muscle activity contribute to the pathogenesis of obstructiv e sleep apnea (OSA). However, some individuals with normal airway size and apparently normal upper airway muscle activity nonetheless develo p OSA. Recent data and analysis suggest that airway shape may also con tribute to the development of OSA; patients with OSA tend to have elli ptical airways, with the long axis of the ellipse oriented along the a nteroposterior axis, and this orientation may adversely affect upper a irway muscle function. By incorporating airway shape, airway size, and upper airway muscle activity into a unified hypothesis of the pathoge nesis of OSA, it may be possible to reconcile discrepant anatomic and electromyographic findings in patients with OSA, to explain the diffic ulty of selecting appropriate surgical therapy for patients with OSA u sing currently available diagnostic tools, and to understand the often disappointing response to upper airway surgery in these patients.