Patient interface systems

A patient interface system for delivery of a supply of air at positive pressure to an entrance of a patient's airways for treatment of sleep disordered breathing, the patient interface system comprising:

• a patient interface structure comprising a flexible one-piece silicone structure at least partially forming a plenum having a seal provided thereto, the seal being adapted to, in use, engage and form a seal with the underside of the patient's nose;
• and
• a flexible seal positioning and stabilizing structure to position and stabilize the patient interface structure in sealing engagement with the patient's airways, the seal positioning and stabilizing structure including:
• a pair of main portions comprising a silicone material, each main portion being configured to, in use, engage a corresponding side of the patient's face between the patient's eye and ear, each main portion having a patient interface structure connector provided at a bottom portion thereof, each patient interface structure connector being removably connected to a corresponding side of the patient interface structure;
• and
• a rear strap connected at respective end portions thereof to the main portions of the seal positioning and stabilizing structure and being configured to, in use, extend around the back of the patient's head at a position above the patient's ears.