How a facelift works: the principles of the SMAS lift

What is the SMAS?

Beneath the skin of the face lies a layer of fat (subcutaneous fat), and beneath that is a thin layer of tissue connected to the facial muscles. This is called the superficial musculoaponeurotic system (SMAS), and in the neck it continues into the platysma muscle.

Pulling on the skin alone puts a great deal of tension on the skin. The basic idea of the SMAS lift is that lifting or tightening the SMAS layer along with the skin can reposition sagging deeper tissues while reducing tension on the skin. One review explained that the various facelift techniques share a common goal of moving the soft tissues of the face safely back into place and keeping the result lasting ^[1].

Ways of handling the SMAS

There are several ways to handle the SMAS, and different authors prefer different methods. The main features of each method are briefly summarized in the list below.

The author of a review introducing the extended SMAS flap lift stated the view that this method produces the best results for improving neck bands, the angle between the neck and jaw, the jawline, and sagging jowls, and explained that it can be combined with deep-plane dissection when needed ^[1]. Lateral SMASectomy removes part of the SMAS where the mobile SMAS meets the fixed SMAS; it was described as producing cosmetic results similar to a traditional SMAS flap while allowing the direction of pull to be adjusted to suit a variety of faces ^[2].

The MACS lift uses a short incision and limited dissection under the skin, and it resuspends the soft tissues of the neck and midcheek by placing purse-string loop sutures through the SMAS and platysma and anchoring them to the deep temporal fascia (the firm tissue layer over the temple muscle) ^[3]. It was reported to be effective in appropriately selected patients, with high satisfaction among both surgeons and patients ^[3].

• Extended SMAS flap: the area beneath the SMAS is widely freed and the SMAS is lifted
• Lateral SMASectomy: part of the SMAS is removed and the edges are stitched together to pull it tight
• MACS lift (minimal access cranial suspension): the tissues are suspended through a short incision with loop sutures
• Extended deep-plane approach: the skin, SMAS, and platysma are lifted together as a single unit

Why the neck is evaluated as well

Sagging in the lower face is connected to the neck, so the two are often evaluated together. The authors who introduced the vertical neck lift aimed to lift the skin, SMAS, and platysma as one unit and move the loose tissue of the neck vertically toward the face, rather than to the side or behind the ear ^[4]. They explained that to do this, the flap is extended from the angle of the jaw down into the neck to release the supporting ligaments of the neck that keep the platysma from being repositioned ^[4].

A review of pitfalls in neck surgery explained that, with the platysma as the dividing line, the shallower structures are easy to reach and therefore prone to overtreatment, while the deeper structures are hard to reach and therefore prone to undertreatment ^[5]. It concluded that a strategy of accurately evaluating every structure of the neck and treating them in balance can be used to prevent and correct these problems ^[5].

How facelifts differ in men

More and more men are seeking facial rejuvenation surgery. One review explained that the aesthetic standards for the male face differ from those for women, and that attractive masculinity is not as closely tied to youthfulness as femininity is ^[6].

As a result, men generally want a somewhat different result from a facelift, and the review summarized that techniques have emerged to rejuvenate the face while maintaining a natural, masculine appearance that does not look operated on ^[6]. It is a good idea to ask during your consultation whether there are any special considerations for men.

Risks and limitations

The authors who introduced lateral SMASectomy named, as one of its advantages, that it can avoid the additional risk of nerve injury that comes with dissecting a SMAS flap ^[2]. This also means that nerve injury is a risk to consider with methods that dissect beneath the SMAS.

In neck surgery, overtreatment or undertreatment can create cosmetic problems, and the literature notes that new complications have also appeared with the arrival of minimally invasive techniques ^[5]. In addition, there are the general risks of surgery, such as bleeding or a collection of blood under the skin (hematoma), infection, scarring, reduced sensation, and asymmetry.

Most of the sources reviewed here are reviews summarizing a particular author's method and experience, and they do not include studies that compare outcomes between methods in numbers. It is therefore difficult to say for certain that any one method lasts longer.

What to check during your consultation

How much the face has sagged, the condition of the skin, and the changes a person wants differ from person to person. Even within the SMAS lift, methods and the extent of surgery vary, so it is best to discuss which approach suits you after an examination.

• Which area bothers you most: the jawline, jowls, neck, or midcheek
• How the SMAS will be handled, and why
• Where the incision will be and how long it will be
• Whether sagging in the neck also needs to be addressed
• Risks such as nerve injury and hematoma, and what recovery involves