Mandibular device treatment in obstructive sleep apnea -A structured therapy adjustment considering night-to-night variability night-to-night variability in mandibular devices

Background Mandibular advancement devices (MAD) are a well-established treatment option for obstructive sleep apnea (OSA). MAD are considered preferably for patients with mild to moderate OSA presenting with a elevated night-to-night variability (NNV). This study aimed to determine the treatment effect of MAD on NNV considering different protrusion distances and patient related outcome (PRO). Methods We conducted a prospective cohort analysis of patients before MAD with 60% and 80% of the maximum protrusion. OSA severity was assessed using a home-sleep test for two consecutive nights. PRO contained the Epworth Sleepiness Scale (ESS) and sleep related quality of life (FOSQ). Results Twenty patients with a median overweight body-mass-index of 27.1 (interquartile range (IQR) 16.3 kg/m²), with a mainly mild to moderate OSA with an apnea -hypopnea index (AHI) of 18.3 / h (IQR 17.7) and elevated ESS of 12.5 (IQR 8.0) were included. As opposed to 80%, 60% protrusion significantly but not 80% relevantly reduced AHI (60%%: 11.2 (IQR 5.5)/h, p = 0.01; 80%: 12.9 (IQR18,0)/h, p = 0.32) and improved the ESS (60%: 8.0 (IQR 10,0); 80%: 10 (IQR 9.0)), with therapy settings. No correlation could be detected between NNV and ESS, and FOSQ changes. Higher baseline NNV was associated with severe OSA ( p = 0.02) but not with gender, overweight, or status post-tonsillectomy. Conclusions OSA improvement is associated with lower NNV; both OSA and NNV are connected to the degree of protrusion. Therefore, higher NNV does not justify the exclusion of candidates for MAD treatment. PRO changes are not visibly affected by NNV but by general OSA changes. These findings may help to define and optimize future study designs for the primary outcome decision between objective OSA parameters and PRO.