A face mask assembly (FMA) for supplying breathable gas to a wearer. The face mask assembly (FMA) includes a mask frame including a support, a facial cushion attached to the mask frame, and a forehead support. The forehead support includes a forehead cushion assembly and an adjustment knob operatively coupled to the forehead cushion assembly. The adjustment knob is threadably engaged with the forehead cushion assembly such that turning movement of the adjustment knob causes the mask frame to be moved between retracted and extended positions with respect to the forehead cushion assembly.