Unique cervical collars and patient interfaces for sleep apnea therapy. One cervical collar features a chin-supporting member whose topside is movable relative to a chest-abutting member. The top side is biased upwardly against the underside of the wearer's chin to maintain an erect head position and closed lower jaw position when the user is asleep, while allowing intentional opening of the mouth during consciousness. The chest-abutting member features a support by which a patient interface is carried thereon to avoid or reduce the need for a separate head-worn securing means. A patient interface employs a venturi-like airway configuration to create a vacuum for securing the patient interface to facial or nasal tissue without head straps or the like. Electrical contacts on the cervical collar detect a positional status of the wearer's lower jaw, and are used to control an operational state of a pressurized air source coupled to the interface.
