Dose-response relationship between mandibular advancement and OSA burden: Dissociated effects on supine and...

A key unresolved mechanistic question in obstructive sleep apnea (OSA) therapy with mandibular advancement devices (MAD) is how incremental advancement affects position-specific disease burden. This study aimed to evaluate the dynamic changes in apnea-hypopnea index (AHI) in different body positions in response to stepwise mandibular advancements, using the mandibular jaw movement (MJM)-based monitoring technology.

A prospective cohort study was conducted in OSA patients eligible for MAD therapy with a standardized titration protocol. Home sleep tests with MJM analysis were performed at baseline, and three successive advancement levels (initial, intermediate, and maximal). Regression analysis with adjustments for time-varying confounding factors was applied to estimate the adjusted changes in residual AHI in supine and non-supine positions.

Ninety-six patients completed titration and follow-up. MAD titration did not significantly modify supine sleep time. Relative to baseline, early and significant improvements were observed for both supine and non-supine AHI at the initial advancement level (relative reduction of -60.1% [95% CI: -67.9; -52.2] and -55.0% [95% CI: -61.1; -48.9], respectively). Thereafter, AHI responses diverged: supine AHI continued a progressive reduction through to end of titration (mean cumulative change: -78.4% [95% CI: -82.7; -74.2]), whereas non-supine AHI showed little additional change beyond the initial improvement (mean cumulative change: -63.3% [95% CI: -68.2; -58.3]). Positional OSA prevalence was reduced from 38.5% at baseline to 18.3% at endpoint.

These findings underscore the value of continuous, home-based monitoring of position-specific residual AHI during MAD titration, and support integrating MJM analysis into MAD therapy workflows.