A mask assembly for a user includes a frame having a main body and lateral connector portions and a cushion component provided to the frame and defining a breathing cavity configured to accommodate at least a portion of the user's nose in use. The cushion component includes a face contacting seal portion adapted to sealingly engage with at least a portion of the user's nose in use. The cushion component has an aperture to communicate pressurized gas from the breathing chamber to the user's airways in use, and a main wall portion, opposite from the aperture, extending upwardly away from the frame. The main wall portion includes a stiffening portion.