A patient interface system without forehead support, comprising: a positioning and stabilising structure including a back portion and a pair of upper and lower straps； a patient interface including a plenum chamber and a seal-forming structure； and a patient interface frame including a pair of rigidiser arms each extending from the frame at a connection point located in a plane substantially parallel to the patient's Frankfort horizontal plane, each rigidiser arm including an upper attachment point, and the frame comprising a pair of lower attachment points for releasable attachment to a respective lower strap； wherein the upper straps can be releasably attached to the upper attachment points such that, when donned by the patient, the upper straps are vertically offset relative to the connection points and substantially parallel to the patient's Frankfort plane. The frame and the plenum chamber comprise corresponding retention feature(s) for releasable connection.
