eMedicine Specialties > Plastic Surgery > Rhytidectomy

Facelift, Extended SMAS

Author: Andrew Jacono, MD, Chief, Section of Facial Plastic and Reconstructive Surgery, The North Shore University Hospital at Manhasset; Assistant Professor, Division of Facial Plastic Surgery, The New York Eye and Ear Infirmary, New York Medical College; Assistant Professor, Department of Head and Neck Surgery, Albert Einstein College of Medicine; Director, The New York Center for Facial Plastic and Laser Surgery
Coauthor(s): David W Furnas, MD, Clinical Professor Emeritus, Department of Surgery, Division of Plastic and Reconstructive Surgery, University of California at Irvine
Contributor Information and Disclosures

Updated: Aug 22, 2008

Introduction

This article describes a technique of cervicofacial rhytidectomy that employs the superficial musculoaponeurotic plane (SMAP) for dissection and flap development. Use of the SMAP gives the surgeon flexibility of design and of flap movement (SMAP flap). Extensive shifting of the facial skin with the full thickness of its fascial-fatty layer allows dramatic improvement of severe gravitational effects. This technique is particularly suitable for patients with advanced aging changes.

For facelifts on the SMAP, a patterned skin excision provides precision for advancement and closure of the facial flaps. The surgeon evaluates the physical properties of the skin of the patient's face and neck, pulling it in various directions, noting extensibility and secondary effects on facial features. The surgeon observes the direction and magnitude of movement that give the best contours. In effect, the facelift is rehearsed. On the basis of these findings, the surgeon plots a detailed pattern for skin excisions. The pattern is recorded by direct measurement and by photographs for reference in the operating room and for future comparisons.

History of the Procedure

When Tessier observed the clinical entity of a superficial musculoaponeurotic system (SMAS) of the face, he motivated Mitz and Peyronie to carry out analysis in the anatomy laboratory.¹ Their findings stimulated surgeons to rethink facial dissection planes. The choices now include planes that are within the subcutaneous layer (eg, standard facelift plane, intrasubcutaneous plane), supraplatysmal planes (eg, SMAP), sub-SMAS planes, subplatysmal planes, preperiosteal planes, subperiosteal planes, and any combination.

In 1963, Limberg published drawings of a facelift in which a typical pattern of skin excision had been rendered as a geometric figure. When the defect was closed, the triangle and trapezoids collapsed into a linear closure, and a convincing lift of the dependent facial skin was illustrated. Limberg's drawings were based on geometry without regard to biomechanics, but they were a prototype for precision in planning.

In 1987, the author reported the use of manual rehearsal of the facelift plan incorporating biomechanical evaluation and plotting the pattern for skin excision with the aid of anthropometric landmarks.

Incidental to illustrations of retaining ligaments of the cheek, in 1989, the author showed the SMAP and subsequently presented a video demonstration of the SMAP flap.

Problem

The superficial surface of the SMAS provides a strategic dissection plane for facial surgery. This superficial musculoareolar plane (ie, SMAP) includes the superficial face of the platysma-SMAS and related surfaces, the superficial temporal fascia, the frontalis, the superficial surface of the facial mimetic muscles, and the superficial cervical fascia over the sternocleidomastoid and posterior triangle. Dissection on this plane liberates a thick flap of skin that includes the cheek mass, malar crescent, and fascial-fatty layer (ie, all soft tissue from the areolar surface of the SMAS to the epidermis). The SMAP flap transmits its lift by the force generated from direct edge-to-edge closure of the patterned excision. Additional lift results from emulating the zygomatic ligaments with sutures and by shortening the zygomaticus major muscle by plication.

The facial integument is disengaged from all practicable restraints so that maximum flap advancement results from minimal force and the surgeon gains wide latitude in repositioning dependent soft tissues.

In this discussion, the SMAS is assumed to be a musculoaponeurotic layer devoid of attached fat and to be a continuous part of the platysma. The fibrous part of the SMAS is a fascial area corresponding clinically (intraoperatively) to a segment of parotideomasseteric fascia. This segment of fascia is a link between the SMAS/platysma and the periauricular dermis through many telae subcutaneae and is thus termed the platysma-auricular fascia (PAF). Anterior to the ear, this fascial sheet becomes the SMAS; anteroinferiorly, the PAF becomes platysma. The superficial surface of the SMAS/platysma is a starting point for a dissection plane that is readily extended over the surface of the orbicularis oculi, the superficial temporal fascia, the frontalis muscle, and the superficial cervical fascia.

When the SMAP is part of the surgical strategy, the pattern of the skin excision is particularly important to the effectiveness of a facelift. Once the facial integument has been released from its retaining ligaments and fusion planes, the force generated in the approximation of the edges of the excisional defect is an important determinant of the new facial contours. An overestimate of the amount of skin to be excised could cause excess tension with vascular compromise, and an underestimate could cause an ineffective operation. For this reason, the design is subjected to careful intraoperative scrutiny so that the pattern can be corrected.

Indications

The SMAP is a utility plane that is excellent for facial rhytidectomy, parotidectomy, placement of free flaps in facial volume defects, and development of local flaps to repair defects from facial tumors. Familiarity with this plane and its anatomic variations is helpful in addressing facial trauma.

The SMAP is useful in any patient who has mature aging changes. This plane can be used in its entirety for correcting the forehead, face, and neck; if a patient desires a brow lift that avoids a hairline incision, an endoscopic brow lift on a deeper plane can be a complementary step.

Previous facial surgery is not a contraindication. For the most part, the SMAP is undisturbed when different dissection planes have been used for the primary lift. When the SMAP was previously used, the repeat SMAP dissection has proved to be different but generally no more difficult than the first dissection. The surgeon must identify, record, and discuss with the patient facial asymmetry, facial nerve weakness, facial nerve synkinesis, or other physical features that may be erroneously attributed to the secondary procedure. Such findings demand special vigilance during the secondary dissection.

The technique of patterned skin excision is useful in facelifts in which skin closure plays an important role in the lifting force. It is particularly useful when the skin sags severely, necessitating a more extensive soft tissue resection than usual. Patterned skin excisions are also useful for small secondary lifting procedures.

These strategies provide predictability, reproducibility, and flexibility with minimum complications. Because the operating time is lengthy, local anesthesia with monitored anesthesia care is uniformly chosen.

For information on other facelift procedures, see the Rhytidectomy section of eMedicine's Plastic Surgery journal. For information and CME activities on aesthetic procedures of all kinds, visit Medscape's Aesthetic Medicine Resource Center.

Relevant Anatomy

The SMAP is a cleavage plane that separates the fascial-fatty layer of skin from the surface of the superficial muscle layer of the face and neck. In many areas, identification of this potential space is obvious. In other areas, retaining ligaments, fascial fusion planes, ambiguous pathways, anatomic variations, and anomalies obscure the cleft. Foremost on the surgeon's mind is the position of the facial nerve and its branches. The facial nerve is protected by (1) blunt dissection underneath the SMAS superficial to the fascia overlying the masseter in which the facial nerves exist, (2) dissecting on structures that cover the facial nerve with certainty, (3) identifying the nerve branches and dissecting over them or beside them, or (4) dissecting in areas that are out of the region of the facial nerve. Familiarity with sensory nerves that occasionally mimic the facial nerve is important, as is knowledge of the supporting structures that must be separated or detached for surgical exposure.

Contraindications

Currently, with endoscopic and short-incision techniques, patients who have mild aging changes of the mid face but youthful lower face and neck areas gain satisfactory improvement. These patients are not candidates for an SMAS facelift.

• Search for CME/CE on This Topic »

• Facelift, Subperiosteal (Plastic Surgery)
• Rhytidectomy, Deep Plane Facelift (Otolaryngology and Facial Plastic Surgery)
• Facelift, Composite (Plastic Surgery)
• Rhytidectomy, Subperiosteal Facelift (Otolaryngology and Facial Plastic Surgery)

• Aesthetic Surgery Education and Research Foundation (ASERF) Elects New Officers: An Expert Interview With ASERF President Laurie Casas, MD
• Overview of Skin Aging and Photoaging