Efficacy and tolerability of a custom-made Narval mandibular repositioning device for the treatment of obstructive sleep apnea: ORCADES study 2-year follow-up data

Objective/background: Mandibular repositioning device (MRD) therapy is an alternative to continuous positive airway pressure (CPAP). The Orkney Complex Disease Study-ORCADES study is assessing the long-term efficacy and tolerability of MRD therapy in obstructive sleep apnoea syndrome (OSAS); two-year follow-up data are presented. Patients/methods: OSAS patients who refused or were noncompliant with CPAP were fitted with a custom-made computer-aided design/computer-aided manufacturing (CAD/CAM) bi-block MRD (ResMed, Narval CC™); mandibular advancement was individually titrated. Sleep and respiratory parameters were determined at baseline, 3–6 months, and two years. The primary endpoint was treatment success (percentage of patients achieving a ≥50% reduction in the apnoea-hypopnoea index [AHI]). Results: Of 315 enrolled patients, 237 remained on MRD treatment at two years, and 197 had follow-up data. The treatment success rate at two years was 67%; AHI <5/h, <10/h and <15/h was achieved in 30%, 56% and 72% of patients, respectively. On multivariate analysis, ≥50% decrease in AHI at 3–6 months and absence of nocturia at 3–6 months were significant predictors of MRD treatment continuation. Adverse events were generally mild, and the majority occurred in the first year of treatment. Conclusions: Two years' treatment with an MRD was effective and well tolerated in patients with mild to severe OSAS who refused or were intolerant of CPAP.