Mandibular Movement Analysis to Assess Efficacy of Oral Appliance Therapy in OSA.

RATIONALE

The respiratory effort index derived from vertical mandibular movements (MM-REI) is a potential marker of increased respiratory effort during sleep. We evaluated the effectiveness of mandibular advancement splint therapy using MM-REI, in comparison with the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI).

METHODS

Fifty-six subjects (median age, 47 years) with OSA treated with a custom mandibular advancement splint (Herbst appliance) were evaluated at the end of the titration procedure when snoring was reported absent by the sleep partner. We employed a magnetometer to capture mandibular movements (Brizzy; Nomics). Mandibular advancement splint efficacy was assessed as the percent change from baseline, using Bayesian multilevel models.

RESULTS

At the end of titration, all indices of OSA severity decreased compared with baseline: AHI (-48.9% to -71.1%), ODI (-49.5% to -77.2%), with obstructive hypopnea index and MM-REI showing the largest responses (-70.6% to -88.5% and -69.5% to -96.3%, respectively). MM-REI normalization via reductions in both mandibular movement event rate and duration accurately reflected efficacy of the appliance.

CONCLUSIONS

The reduction of vertical respiratory mandibular movements estimated by MM-REI and sleep respiratory effort duration accompanied the decrease in obstructive hypopneas, AHI, and ODI when snoring resolved in subjects with OSA treated with an optimally titrated mandibular advancement splint.