A respiratory mask assembly for treatment of sleep disordered breathing, the respiratory mask assembly comprising a frame and a cushion which at least in part defines a cavity adapted to receive at least a patient&rsquos nose. The cushion includes a face contacting portion, a non-face contacting portion, and a gusset portion between the face contacting portion and the non-face contacting portion. When seen in cross-section, the gusset portion includes a hanging portion that hangs over an adjacent exterior surface of the cushion a first end (lower end, in drawing) adjacent to the face contacting portion and a second end (upper end, in drawing) adjacent to the non-face contacting portion, the first end being further from a centre of the mask than the second end. The respiratory mask assembly also includes an air delivery connection supported by the frame and adapted to connect an air delivery conduit to supply air to the cavity.
