Which feature predisposes to obstructive sleep apnea?

• A. Thin stature
• B. Hyperthyroidism
• C. Branchial cleft cyst
• D. Micrognathia

Answer: (D)

Obstructive sleep apnea happens when the upper airway becomes temporarily blocked during sleep due to a structurally narrow or collapsible airway. Micrognathia, or a small mandible, reduces the space in the oral and pharyngeal regions so the tongue sits closer to the back of the throat. When sleep brings reduced muscle tone, this configuration makes the airway more likely to collapse, causing obstructive events.

Other options don’t shape the airway in this way: a thin stature doesn’t inherently narrow the pharyngeal space, hyperthyroidism isn’t a typical direct predisposition to OSA, and a branchial cleft cyst is a neck mass rather than a factor that increases nocturnal airway collapse.