A mask system (1) for treating sleep disordered breathing, comprising: harness (20) a unit mask and pad (30, 130, 230, 330) that fits a patient when used, and having 1 May opening (30.3), the unit mask and pad (30, 130, 230, 330 ) at least one flange (36, 330.1) and defining a cavity (30.1) a frame (40, 140, 440) for supporting the unit mask and pad (30, 130, 230, 330), the frame (40, 140, 440) substantially shaped to conform to the shape of, at least, a flange (36, 330.1) of the unit mask and pad (30, 130, 230, 330), so that the frame (40, 140, 440) is fixed to the unit mask and pad (30, 130, 230, 330) a retaining ring (60, 160) including a rear flange (66) located adjacent the opening of the mask and pad unit (30, 130, 230, 330) and an elbow (50, 150, 250, 350) which engages the retaining ring (60, 160) characterized in that the unit mask and pad (30, 130, 230, 330) is constructed from a flexible material that the unit mask and pad (30, 130, 230, 330) is molded from silicone and that the frame (40, 140, 440) can be located adjacently to at least one flange (36, 330.1) of the unit mask and pad (30, 130, 230, 330).Un sistema de máscara (1) para tratar el trastorno respiratorio del sueño, que comprende: arnés (20) una unidad de mascarilla y almohadilla (30, 130, 230, 330) que se ajusta a un paciente cuando se usa, y que tiene una 5 abertura (30.3), teniendo la unidad de mascarilla y almohadilla (30, 130, 230, 330) por lo menos un reborde (36, 330.1) y definiendo una cavidad (30.1) un marco (40, 140, 440) para soportar la unidad de mascarilla y almohadilla (30, 130, 230, 330), estando el marco (40, 140, 440) sustancialmente conformado para ajustarse a la forma de, por lo menos, un reborde (36, 330.1) de la unidad de mascarilla y almohadilla (30, 130, 230, 330), de manera que el marco (40, 140, 440) esté fijado a la unidad de mascarilla y almohadilla (30, 130, 230, 330) un anillo de retención (60, 160) que incluye un reborde trasero (66) situado adyacentemente a la abe
