The platysma is a thin layer or sheet of muscle in the neck. The platysma muscle sags with age and contributes to the appearance of “bands” in the central neck area. The platysma is continuous with the SMAS (superficial musculo-aponeurotic system), a layer of fat and muscle tissue just under the skin surface of the face. Modification of the SMAS is the main component of most facelift surgery, not just the skin. Long-lasting facelift results are obtained by lifting and tightening the SMAS through a variety of techniques.