Pilot analysis of magnetic resonance imaging-based contributors to patient-centred optimization of mandibular advancement devices in obstructive sleep apnea.

Mandibular advancement devices are an effective treatment option for obstructive sleep apnea. While their efficacy depends on the degree of mandibular protrusion, other contributing factors influencing the optimal outcome are not fully understood. This magnetic resonance imaging-based pilot study aimed at investigating whether there are promising planimetric parameters that may be related to the optimal therapeutic position. A second aim was to assess possible sex-specific differences. Planimetric data from magnetic resonance imaging taken in the habitual position and four protrusion grades were collected from 11 female and 14 male patients with obstructive sleep apnea (age 45 ± 13.3 years; body mass index 27.6 ± 4.5 kg m^-2). Data were correlated with outcome as substantiated by polygraphic data obtained at the habitual position and at each of two protrusion positions considered to reveal the highest treatment effect. Protrusion degree and lateral widening of the retropalatal region correlated most strongly (R = 0.56, p < 0.001). Relationships between planimetric data and treatment success were most pronounced at the level of the smallest cross-section, expressed, for example, by a correlation between oxygen desaturation index and lateral diameter (R = -0.4, p = 0.012). Female participants appeared to show improved polygraphic values at a lower protrusion degree than males. Data from magnetic resonance imaging allow for a comprehensive analysis combining insights from planimetric velopharyngeal measurements at different individual protrusion grades and correlation with outcome. The results of this pilot work encourage further evaluation in large-scale studies. These should focus on the velopharyngeal region and investigate the influence of sex more closely.