Background: Adherence to continuous positive airway pressure (CPAP) for obstructive sleep apnoea (OSA) continues to be low with high termination rates. Alternative therapies to CPAP are needed. Our objective was to compare objective adherence to CPAP and mandibular advancement splints (MAS) and to evaluate their effectiveness, and additionally to identify treatment usage patterns and the clinical effectiveness of having both therapies.Methods: This multicentre, double-randomised, three-phase trial (titration/crossover/observation) was conducted at three Canadian universities. Eligible participants were treatment-naïve with mild-to-severe OSA. The primary outcome was objectively measured adherence (hours per night) during the crossover phase. Secondary outcomes included efficacy during the crossover phase; adherence during the observational phase; and patient-centred outcomes, blood pressure and side-effects during the crossover and observational phases. Duration of the crossover and observational phase was 2.5 and 6 months, respectively.Results: 81 participants were enrolled in the first randomisation. 79 entered the adaptation/titration phase (mean±sdage 52.3±10.8 years; 58 males), 73 entered the crossover phase (included in the intention-to-treat analysis) and 64 completed the observational phase. Mean objective adherence over 1 month: MAS showed higher adherence than CPAP, 6.0versus5.3 h·night⁻¹(difference 0.7 (95% CI 0.3–1.2) h·night⁻¹; p<0.001). Mean CPAP−MAS difference in efficacy: 10.4 (95% CI 7.8–13.0) events·h⁻¹; p<0.001. During the observational phase 55% (35 out of 64) of participants chose to alternate therapies. All treatments led to substantial improvement in patient-centred outcomes.Conclusions: Despite the higher efficacy of CPAP and higher adherence to MAS, both demonstrate comparable clinical effectiveness on patient-centred outcomes. Having both CPAP and MAS can improve long-term management of OSA.

Introduction: Obstructive sleep apnea (OSA) is a disorder in which ventilation becomes disrupted due to a complete or partial upper airway obstruction Altered craniofacial morphology is one of the most important anatomical factors associated with obstructive sleep apnea (OSA). Studies have assessed craniofacial features in the non-syndromic pediatric population. The aim of this study was to analyze the orthodontic and facial characteristic of craniofacial syndromic children referred for polysomnography (PSG) and to assess the correlation with the apnea–hypopnea index (AHI). Methods: In the current cross-sectional study, consecutive syndromic patients referred for PSG were invited to participate. A systematic clinical examination including extra- and intra-oral orthodontic examination was performed by calibrated orthodontists. Standardized frontal and profile photographs with reference points were taken and analyzed using ImageJ^® software to study the craniofacial morphology. PSG data were analyzed for correlation with craniofacial features. STROBE guidelines were strictly adopted during the research presentation. Results: The sample included 52 syndromic patients (50% females, mean age 9.38 ± 3.36 years) diagnosed with 17 different syndromes, of which 24 patients had craniofacial photography analysis carried out. Most of the sample (40%) had severe OSA, while only 5.8% had no OSA. Down’s syndrome (DS) was the most common syndrome (40%) followed by Goldenhar syndrome (5%), Pierre Robin Sequence (5%), and other syndromes. The severity of AHI was significantly correlated with decreased midfacial height. increased thyromental angle and cervicomental angle, decreased mandibular angle, and decreased upper facial height. All patients with DS were diagnosed with OSA (57% severe OSA), and their ODI was significantly correlated with increased intercanthal distance. Obesity was not correlated to the severity of AHI for syndromic patients. Conclusions: Decreased midfacial height and obtuse thyromental angle were correlated with increased AHI for syndromic patients. Increased intercanthal distance of DS patients could be a major predictor of OSA severity. Obesity does not seem to play a major role in the severity of OSA for syndromic patients. Further studies with larger samples are necessary to confirm these findings.