A respiratory mask assembly for treatment of sleep disordered breathing includes a frame, a cushion which at least in part defines a cavity adapted to receive at least a patient's nose, and an air delivery connection supported by the frame and adapted to connect an air delivery conduit to supply air to the cavity. 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. The gusset portion includes a hanging portion that, when seen in cross-section, hangs over an adjacent exterior surface of the cushion. The gusset portion includes a first point adjacent to the face contacting portion and a second point adjacent to the non-face contacting portion, and the first point is offset radially outwardly from the second point.