A patient interface for treatment of a user having a respiratory disorder, the patient interface including: a nasal portion having at least one nasal portion aperture (18, 55) adapted to be in communication with a supply of pressurized gas for delivery of the pressurized gas to at least one nasal opening of the user; and a mouth portion (20, 58) having at least one mouth portion aperture (24, 62, 114, 118, 122) also adapted to be in communication with the supply of pressurized gas to deliver the pressurized gas to an oral cavity of the user's mouth, wherein the at least one mouth portion aperture (24, 62, 114, 118, 122) is separate from the at least one nasal portion aperture (18, 55), and the patient interface is adapted to limit a flow of the pressurized gas out of the at least one mouth portion aperture (18, 55) to be no greater than a flow of the pressurized gas out of the at least one nasal portion aperture, wherein the patient interface further comprises an adaptor (65, 87) adapted to engage the mouth portion (20, 58) and the nasal portion, wherein the adaptor (65, 87) includes a first conduit adapted to deliver the pressurized gas to the nasal portion and a second conduit adapted to deliver the pressurized gas to the mouth portion (20, 58), and characterized by a restrictor portion configured to allow patient selective adjustment of the flow of the pressurized gas to the at least one mouth portion aperture (24, 62, 114, 118, 122), whereby the selective adjustment of the restrictor portion controls the flow of gas out of the mouth portion (20, 58) to be no more than the flow of gas to the nasal portion or to a lower fixed or absolute level, wherein the patient interface further comprising an adaptor aperture between the first conduit and the second conduit, wherein an area of the adaptor aperture limits a flowrate of the pressurized gas to the mouth portion (20, 58) to be nor more than a flowrate of the pressurized gas to the nasal portion. a nasal portion having at least one nasal portion aperture (18, 55) adapted to be in communication with a supply of pressurized gas for delivery of the pressurized gas to at least one nasal opening of the user; and a mouth portion (20, 58) having at least one mouth portion aperture (24, 62, 114, 118, 122) also adapted to be in communication with the supply of pressurized gas to deliver the pressurized gas to an oral cavity of the user's mouth, wherein the at least one mouth portion aperture (24, 62, 114, 118, 122) is separate from the at least one nasal portion aperture (18, 55), and the patient interface is adapted to limit a flow of the pressurized gas out of the at least one mouth portion aperture (18, 55) to be no greater than a flow of the pressurized gas out of the at least one nasal portion aperture, wherein the patient interface further comprises an adaptor (65, 87) adapted to engage the mouth portion (20, 58) and the nasal portion, wherein the adaptor (65, 87) includes a first conduit adapted to deliver the pressurized gas to the nasal portion and a second conduit adapted to deliver the pressurized gas to the mouth portion (20, 58), and characterized by a restrictor portion configured to allow patient selective adjustment of the flow of the pressurized gas to the at least one mouth portion aperture (24, 62, 114, 118, 122), whereby the selective adjustment of the restrictor portion controls the flow of gas out of the mouth portion (20, 58) to be no more than the flow of gas to the nasal portion or to a lower fixed or absolute level, wherein the patient interface further comprising an adaptor aperture between the first conduit and the second conduit, wherein an area of the adaptor aperture limits a flowrate of the pressurized gas to the mouth portion (20, 58) to be nor more than a flowrate of the pressurized gas to the nasal portion.