MADs used in the two study arms. MADs used in the two study arms. (A) ONIRIS is a two-piece innovative adjustable thermoplastic MAD combining a precise teeth impression, is titratable and allows free jaw movements and mouth opening (ONIRIS SAS). (B) TALI is a two-piece acrylic custom-made MAD, is titratable and allows free jaw movements and mouth opening (ONIRIS SAS). MADs, mandibular advancement devices. Jean Louis Pépin et al. Thorax 2019;74:667-674 Copyright © BMJ Publishing Group Ltd & British Thoracic Society. All rights reserved.