Obstructive sleep apnea (OSA) is often a multi-level upper airway disorder in which anatomic factors in the nose, oral cavity, and throat collectively leads to obstruction during sleep. Nasal factors include deviated septum, turbinate hypertrophy, and adenoid hypertrophy. Oral cavity factors include large tongue, large tonsils, and uvular-palatal hypertrophy. Factors in the throat include large base of tongue and rarely, problems related to the voice box.
Where ever there is obstruction, the obstruction should be removed, that is the principle of OSA surgery, only a multilevel approach can cure the patient from severe OSA.