5.1 Introduction

In the course of evolution, humans for the most part have lost the subdermal layer of muscles that covers the entire surface of many lower animals, and contracts around wounds, or contracts to flick off insects. Remnants of this musculocutaneous sheet exist in the skin as a fibrofatty layer. Because there are numerous connections via vertical fibrous septa, from the upper fibrofatty layer to the dermis of the skin and the fibro- fatty-aponeurotic fascia encircles, envelopes, and interconnects the muscles of facial expression as a single unit, this interconnected system amplifies, transmits, and distributes mimetic muscular contractions, and translates them into a rich variety of complex facial expressions. Below the neck, only the Dartos muscle in the skin of the scrotum retains a muscular component. However, on the face and anterior neck, the superficial muscle layer has been retained, interposed

H.A. Khawaja ( )

Cosmetic Surgery & Skin Center, 53 A, Block B II, Gulberg III, 54660 Lahore, Pakistan

e-mail: drhassan@nexlinx.net.pk, drhassan7@hotmail.com

M.A. Shiffman

17501 Chatham Drive,

Tustin, California 92780-2302, USA e-mail: shiffmanmdjd@yahoo.com

E. Hernández-Pérez

Centro De Dermatologia Y Cirugia Cosmetica, Villavicencio Plaza Suites 3-1, 3-2,

Paseo Escalón y 99 Av. Norte,

San Salvador, 01-177 El Salvador, C.A. e-mail: drenrique@hernandezperez.com

between the skin and muscles of mastication. The purely muscular component consists of muscles of facial expression, whereas the fibrotic or aponeurotic component is referred to as the SMAS [1]. Somewhat confusingly, the fibrous portion of the SMAS, has also retained its designation as superficial fascia. Since its discovery, SMAS concept is not very clear cut, and confusion centers around its various components.

The SMAS consists of not only the fibro-aponeurotic part, but is a single unit “fibro-aponeurotic-fatty-fleshy system.” The authors designate it as SMAFS (superficial musculoaponeurotic-fatty system). Therefore, SMAFS consists of a fibro-aponeurotic part, a superficial fatty layer, and superficial muscles of facial expression, as a single unit.

The lower subdivision of SMAFS, especially, is subject to considerable variations. Performing hundreds of facelifts over the last several years, we have seen variations such as thin and membranous SMAFS, thick and membranous SMAFS, thick and fibrous SMAFS, fibrofatty SMAFS, thick fleshy SMAFS, more fatty and less fibrous SMAFS, very fatty SMAFS, and patchy and broken down thin/thick SMAFS (which we call Island SMAFS). In addition, we have noticed attachment and regional variations; for example, not a very clear supraand infrazygomatic divisions of SMAFS and discontinuity between the facial and neck SMAFS. Patchy/broken down SMAFS has been noticed by us either as a congenital anomaly or, apparently as a result of repeated Botox injections for obliterating the smile lines, lines around the cheek, nasolabial folds, and other facial/neck area lines. Broken down SMAFS has also been noticed as a result of repeated steroid injections into the face. Fatty SMAFS is noted in obese patients and those with well

developed and prominent cheeks. In thin patients, there may be fatty SMAFS as a result of repeated facial fat injections especially into the cheek region. There are considerable variations of anatomical landmarks especially frontal and marginal mandibular nerves in relation to the SMAFS.

The type, nature, and variations of SMAFS have an impact on the outcome of facelift surgery. Therefore, it is important for all surgeons, performing facelift surgery, to understand in detail the various types of SMAFS, and their variations, and plan the correct operative technique of debulking, plicating, lifting, and attaching the SMAFS to the bony periosteum, according to the nature and type of SMAFS present, in order to achieve good results. This is the aim of the following study.

5.2 Studies and Technique

The SMAFS (superficial musculoaponeurotic-fatty system) was studied in 800 facelift (Classical, Delta, S-lift, and Transcutaneous facelift) surgeries (661 females and 139 males) from August 1998 to March 2007, and the results of facelifts were analyzed according to the type of SMAFS. The age of the patients varied between 36 and 78 years. All patients were healthy, were not suffering from any physical or mental disability or illnesses. All female patients were nonpregnant and non-lactating. Seventy percent of the patients were of Fitzpatrick skin type III or IV and 30% of the patients were of skin type I or II. Preoperative SMAFS assessment was carried out in all cases. Facelifts in 70% of the patients were carried out as a result of sagging of skin and SMAFS, while in 30% of the cases, it was carried out to achieve a more youthful appearance in the face (for facial tightening). Faces of 75% of the patients were thin, while 25% of the patients had chubby (fatty) faces. A consent form was signed by all the patients. Preand postoperative photographs (after 1 month and 1 year) were taken in all cases. Intraoperative gross SMAFS assessment was for thickness, thinness, consistency, continuity, nature, type of tissue present, mixed nature of the tissues present, density, tone, elasticity, rigidity, flaccidity, fattiness, fleshiness, breakage, and gaps in SMAFS (gross parameters), and were studied in detail.

In cases where the SMAFS was found to be thin, membranous, and flaccid, plication using Prolene 2/0 sutures, below the zygomatic arch, as in a Delta-lift or lifting and attaching to proximal zygoma, as in an S-lift, using vertical U and horizontal O sutures were carried out. In cases of classical lift, plication of SMAFS below the zygomatic arch was carried out using two Prolene sutures. In cases, where the SMAFS was found to be considerably fatty, as assessed preoperatively, closed liposuction using keel cobra tip or flat spatula cannula was carried out initially, in order to defat the SMAFS considerably; subsequently, lift was carried out as in a Classical, Delta, or S-lift. In cases of mild to moderately fatty SMAFS, defatting was carried out using open vacuum cleaner technique with a flat spatula cannula prior to Classical/Delta/S-lift. In cases where the SMAFS was found to be fleshy, thick, or rigid, relatively deeper and more SMAFS bites were taken and the SMAFS was attached to the periosteum of zygomatic arch. In cases where the SMAFS was found to be patchy, broken (Island SMAFS), or discontinuous, the aim was not to provide lift, but to restore continuity of SMAFS. In cases, where one or two discontinuous areas were present, the SMAFS was repaired and mild to moderate lift was provided while in other cases, SMAFS plication and lift was carried out after a year. In cases of mixed SMAFS, combination of liposuction, plication, and lifting were carried out according to the type of tissues present in the SMAFS. Bites of SMAFS were taken using curved needles with attached Prolene 2/0 through the superficial muscular part of SMAFS, in all cases, including thin and membranous SMAFS.

In cases where transcutaneous facelift (TCFL) was planned, preoperative SMAFS assessment with the thumb and index finger (Pinch Test) was carried out to assess density, tone, flaccidity, thickness, thinness, gaps, nature, tissue type, mixed patterns, and other palpable SMAFS parameters. In cases where the SMAFS was thin, membranous, and flaccid, superficial SMAFS bites, using the Khawaja-Hernandez (KH) needle, or the Keith needle and two to three sutures of Prolene 2/0, for lifting, were used. Where the SMAFS was thick, fatty, or fleshy, relatively deeper and more SMAFS bites were taken. More lift was provided in these cases. In all cases of TCFL, bites of SMAFS were taken through the superficial muscular layer and Prolene threads were attached to the thick temporal fascia or periosteum of the temporal bone.