An patient interface that reliably maintains a seal between it and the patient. The patient interface advantageously includes a deformation portion at its point of connection with an air supply, with the deformation portion being relatively more deformable than the other portions of the patient interface in order to resist torque applied by the air supply from disturbing the seal between the patient interface and the patient. While the air supply is pivotably connected with the patient interface and is pivotable about a pivot axis, a torque applied about an axis other than the pivot axis results in deformation of the deformation portion and thus advantageously avoids breaking the seal between the patient interface and the patient.
