The SMAS and the nasolabial fold.

In a series of histologic sections and clinical and cadaver dissections, the superficial musculoaponeurotic system (SMAS) is seen to become the investing fascia of the zygomaticus major and minor muscles in the medial cheek. The pull on the cheek flap during rhytidectomy is diffused by the attachment of the SMAS to these muscles. I believe that this attachment accounts for the minimal change in the nasolabial crease after a Skoog-type sub-SMAS face lift.