A sleep apnoea treatment device comprises a mouthpiece including a vestibular locator and an airway conduit. The vestibular locator is adapted for positioning in the mouth vestibule of a user interposed between the lips and teeth of the user. The vestibular locator is to support the airway conduit in place relative to the user's mouth with the airway conduit extending between the lips of the user whereby the airway conduit maintains fluid communication of the mouth vestibule with ambient air to facilitate the user breathing ambient air through the airway conduit.
