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

Abstract

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). 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. 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. 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.