The effect of mask choice on adherence to positive airway pressure treatment for obstructive sleep apnea in adults.

PURPOSE OF REVIEW: Mask choice is among the few modifiable determinants of positive airway pressure (PAP) effectiveness in adults with obstructive sleep apnea OSA), yet selection is often shaped by convention, habit, or local inventory rather than evidence. We review recent literature, emphasizing studies from the past 18 months and incorporating foundational mechanistic and outcomes studies that should influence prescribing choices. RECENT FINDINGS: Population-scale telemonitoring analyses confirm that nasal interfaces outperform oronasal masks on adherence, required pressure, residual apnea-hypopnea index (AHI), and unintentional leak. Switching patients from an oronasal to a nasal mask can increase adherence by up to 77%. Drug-induced sleep endoscopy with PAP, cine MRI, and sealed-compartment physiology suggest three main mechanisms for these observations: oral pressure transmission without oral airflow, posterior tongue and mandibular displacement, and increased pharyngeal collapsibility. Mandibular jaw-movement signals allow leak phenotyping that distinguishes mask-seal failure from mouth opening, supporting targeted intervention rather than reflexive interface change. SUMMARY: Current evidence supports a nasal-first prescribing strategy with structured early follow-up using telemonitored adherence, residual AHI, and leak waveform data. Oronasal masks should be reserved for documented and structured nasal-trial failure rather than selected on the basis of self-reported breathing route.