Tong BK, Tran C, Ricciardiello A, et al. - Since the role of posture and mandibular advancement on nasal resistance in OSA is not clear, researchers performed this investigation to discover the impacts of posture and mandibular advancement on nasal resistance in OSA and to analyze the effectiveness of a new OA device including in individuals with high nasal resistance. Thirty-nine people with OSA (7 females, AHI (mean ± SD) = 29 ± 21 events/h) finished split-night polysomnography with and without OA (order randomized). According to results, awake nasal resistance rose from seated to supine, to lateral posture. In people with OSA, nasal resistance changes with posture. A novel oral appliance with an in-built oral airway decreases the severity of OSA in people with OSA, including those with high nasal resistance.