A patient interface structure includes a cushion configured to sealingly engage the patient's face and a front that is more rigid than the cushion. The cushion includes a forward opening, a rearward opening that is opposite the forward opening and a continuous sealing surface. The continuous sealing surface has a mouth sealing portion configured to seal around the patient's mouth and a nasal sealing portion configured to seal around both of the patient's nasal airways. The front plate includes an air inlet configured to both receive the pressurized respiratory gas and secure headgear to the patient interface structure. In addition, the nasal sealing portion includes at least one aperture that is separate from the rearward opening. Also, the front plate, the mouth sealing portion and the nasal sealing portion together form a common chamber.