What the research shows
The SMAS was first described in 1976 from dissections of the cheek and the area over the parotid gland. Working beneath it was safe over the gland and dangerous in front of it, where the facial nerve branches run (Mitz 1976). In the inner cheek the SMAS wraps the muscles that lift the corner of the mouth, which explains why a SMAS lift changes the fold beside the nose less than the jowl (Barton 1992).
Surgeons handle the layer in four main ways. Plication folds it and stitches it without cutting. Imbrication or SMASectomy cuts out a strip and sews the edges together. A SMAS flap raises the layer and moves it, and the high lateral SMAS and composite lifts are extended versions of the flap (Jacono 2019).
All of them are safe, and their risks differ slightly. Pooled across studies, the most common problems were temporary facial nerve weakness and small areas of skin loss, each in fewer than 1 in 100, and only one permanent nerve injury was reported (Mortada 2024). The more extensive high SMAS and composite lifts had more temporary nerve weakness than plication; the risk of permanent injury did not differ among methods (Jacono 2019). At one academic center, lifts that raised a SMAS flap had no more complications than skin lifts with plication (Rammos 2015). Age alone did not raise risk, even past 75, in carefully screened patients (Vishwanath 2026).
More release lifts more on the table. Measured during surgery on the same face, a deep plane release moved tissue further and freed more excess skin than imbrication, and imbrication more than plication (Litner 2006). In the neck, plication moved the central platysma far less than a deep plane release, so surgeons who plicate add a midline neck repair when the neck is loose (Jacono 2011).
Where surgeons disagree
- Whether more dissection gives a better result. In a randomized trial using each patient as her own control, the more extensive side looked better on the operating table, but the difference was gone within a day and was not visible at six or twelve months (Ivy 1996). Masked reviewers rated plication lifts higher than deep plane lifts in patients under 70 (Becker 2004), while another blinded review found the deep plane better in the midface and neck (Adamson 2007).
- How long the result lasts. One surgeon's patients needed a later tuck more often after SMAS lifts than after deep plane lifts (Kamer 1998). A recent review found that deep plane methods have not been shown to improve the midface or to last longer (Schultz 2026).
What is new
- A randomized trial of deep plane, high SMAS and plication lifts found the same reduction in apparent age with all three (Baptista 2026).
- Dye imaging during surgery showed no measurable blood flow in a raised lower-cheek SMAS flap, which favors composite lifts or less skin dissection in high-risk patients (Lai 2026).
- A high and extended SMAS practice lowered blood collections to about 3 in 1,000 with tranexamic acid, fibrin glue, hemostatic nets and blood pressure control (Lazzeri Domar 2026).
What is still unknown
- Which method gives the best result: some studies leave out complications, and no technique has been ranked on appearance (Mortada 2024).
- How long each method lasts: a SMAS flap lift averaged about twelve years before a second lift, but no trial compares methods over that span (Sundine 2010).
Key papers
- Mitz 1976: named and described the SMAS.
- Barton 1992: why a SMAS lift changes the fold beside the nose less than the jowl.
- Ivy 1996: randomized half-face trial; extensive and limited SMAS lifts ended up the same.
- Kamer 1998: fewer later tucks after deep plane than SMAS lifts.
- Becker 2004: plication matched or beat deep plane in patients under 70.
- Litner 2006: how far each method moves tissue during surgery.
- Jacono 2019: complication rates for each SMAS method.
- Mortada 2024: high satisfaction across SMAS methods.
- Schultz 2026: deeper release has not been shown to last longer.