An interface for use in providing positive pressure respiratory therapy, the interface comprising: a mask assembly (100,1400) comprising a mask seal (104,1404) and a mask shell (102,1402), the mask assembly (100,1400) configured to be positioned on a face of a user covering the mouth of the user and sealing under the nose of the user, the mask shell (102,1402) comprising a central portion and a pair of wings sweeping rearwardly of the central portion, an opening for a connector being formed in the mask shell (102,1402) in the central portion, the mask seal (104,1404) being connected to the mask shell (102,1402), the mask seal (104,1404) comprising a lower portion and an upper portion, at least one nasal opening being positioned on the upper portion, at least one oral opening being positioned on the lower portion opposite of the opening for the connector, the mask assembly (100,1400) comprising one or more features (120,1110) that decouple movement of the upper portion and the lower portion to allow relative rotational movement therebetween about a lateral axis that extends in a direction that is substantially perpendicular to a longitudinal axis extending in the front to back direction of the mask seal (104,1404), the one or more features that decouple movement being a crease or one or more bellows features, the upper portion of the mask seal (104,1404) comprising a first paddle, a second paddle, and a nasal region having an upper support surface being positioned between the first paddle and the second paddle such that an upwardly-open valley is defined by the first paddle, the upper support surface and the second paddle, at least a portion of the at least one nasal opening being positioned on the upper support surface within the valley, the mask assembly being configured not to extend over or not to enshroud the tip of the nose of the user in use, wherein the first paddle and the second paddle are configured to extend upward above the nares of the user and contact the sides of the user's nose and a frame assembly coupled to the mask assembly (100,1400), the frame assembly configured for connection to a headgear, wherein the interface further comprises a movement limiting arrangement that limits movement of the upper portion of the mask seal (104,1404) relative to the lower portion of the mask seal (104,1404) and that is configured to: permit downward movement of the upper portion; and limit upward movement of the upper portion when the upper portion is expanded or when a gas pressure within the mask seal is at or above a threshold gas pressure. a mask assembly (100,1400) comprising a mask seal (104,1404) and a mask shell (102,1402), the mask assembly (100,1400) configured to be positioned on a face of a user covering the mouth of the user and sealing under the nose of the user, the mask shell (102,1402) comprising a central portion and a pair of wings sweeping rearwardly of the central portion, an opening for a connector being formed in the mask shell (102,1402) in the central portion, the mask seal (104,1404) being connected to the mask shell (102,1402), the mask seal (104,1404) comprising a lower portion and an upper portion, at least one nasal opening being positioned on the upper portion, at least one oral opening being positioned on the lower portion opposite of the opening for the connector, the mask assembly (100,1400) comprising one or more features (120,1110) that decouple movement of the upper portion and the lower portion to allow relative rotational movement therebetween about a lateral axis that extends in a direction that is substantially perpendicular to a longitudinal axis extending in the front to back direction of the mask seal (104,1404), the one or more features that decouple movement being a crease or one or more bellows features, the upper portion of the mask seal (104,1404) comprising a first paddle, a second paddle, and a nasal region having an upper support surface being positioned between the first paddle and the second paddle such that an upwardly-open valley is defined by the first paddle, the upper support surface and the second paddle, at least a portion of the at least one nasal opening being positioned on the upper support surface within the valley, the mask assembly being configured not to extend over or not to enshroud the tip of the nose of the user in use, wherein the first paddle and the second paddle are configured to extend upward above the nares of the user and contact the sides of the user's nose and a frame assembly coupled to the mask assembly (100,1400), the frame assembly configured for connection to a headgear, wherein the interface further comprises a movement limiting arrangement that limits movement of the upper portion of the mask seal (104,1404) relative to the lower portion of the mask seal (104,1404) and that is configured to: permit downward movement of the upper portion; and limit upward movement of the upper portion when the upper portion is expanded or when a gas pressure within the mask seal is at or above a threshold gas pressure.