SMAS Facelift Rhytidectomy

Patients who seek consultation for rhytidectomy are concerned about the aging of their facial features. These features include sagging cheeks, jowl, and buccolabial folds and redundant and bulky submental and cervical tissues. ^[1] The goal of the facial plastic surgeon is to determine the characteristics that are contributing to the patient's aging appearance and which of the characteristics are reversible. A comprehensive approach to the aging face may include endoscopic brow and/or midface lifting, blepharoplasty, chin and malar implantation, and chemical/laser exfoliation in addition to rhytidectomy. This article focuses on superficial musculoaponeurotic system (SMAS) rhytidectomy. ^{[2, 3, 4]}

The image below depicts the pictures of a woman before and after rhytidectomy.

Before and after biplanar face lift with lower eyelid blepharoplasty and chin augmentation.

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The ideal rhytidectomy candidate is a middle-aged woman with a fair or medium complexion and a minimal amount of adipose tissue and moderate skin laxity in the jowl and cervicomental regions. An individual with a strong, attractive underlying osseous framework, including prominent zygomatic arches, obtains even further enhancement. Conversely, an individual who is overweight with hyperpigmented thick skin does not obtain optimal results. Individuals with ptotic submandibular glands and an inferiorly positioned hyoid have a more obtuse cervicomental angle and obtain less-than-optimal results.

A cadaveric study by Rao et al comparing skin-only, SMAS plication, and extended SMAS facelifts reported that lifting along the horizontal and vertical vectors was significantly greater for the SMAS operations than for the skin-only surgery. Indeed, no appreciable vertical elevation was seen with the skin-only procedures. For all three methods, the greatest horizontal lift was achieved in the lower face, the aggregate lifts for this region being 0.72 cm, 1.27 cm, and 1.28 cm for the skin-only, SMAS plication, and extended SMAS lifts, respectively. ^[5]

According to The Aesthetic Society, approximately 87,000 facelifts were performed in the United States in 2021. It was in the top six cosmetic surgery procedures for men that year, but not for women. ^[6]

See the list below:

• Aging is characterized by tissue atrophy and reduction in skin's cellular and protein components.

• Gravitational redistribution of soft tissues occurs.

• Sun exposure contributes to the clinical changes observed in the aging face.

Histologically, the skin epidermis thins with retraction of the rete pegs. Decreasing numbers of melanocytes create areas of uneven pigmentary changes. In the dermis, elastic filaments become thin and fragmented, increasing skin laxity. Dermal collagen becomes more biochemically stable, but it is reduced in quantity. Vascular supply is also reduced, resulting in a pale appearance.

Subcutaneous tissues undergo fat atrophy with gravitational redistribution of soft tissues. With skin laxity, whole regions of the facial skin begin to sag and loosen. Habitual facial expressions can lead to progressive recontouring of the subcutaneous layer, and, hence, coarse wrinkles and deep folds develop.

Age-related changes in bone density also affect the facial skeleton. Loss of bone mass in the mandible, maxilla, and frontal bones induce increased sagging of the forehead and facial skin. This process contributes to the perception of a sagging neckline and the occurrence of jowling along the mandible with a loss of a clear delineation between the jaw line and the neck.

Sun exposure contributes to the clinical changes observed in the aging face. Sun-damaged epidermis is characterized by a reduction in structural elements that leads to skin wrinkling. Elastic fibers grow thickened and disorganized, a process called elastosis, and dermal collagen becomes degenerated.

The main surgical criterion is whether a technically sound rhytidectomy can change the individual's appearance to a more youthful one. The benefits of a rhytidectomy are limited to tightening and resupporting the tissues of the lower two thirds of the face. These include the jowl, submentum, anterior neck, and, depending on the face-lifting technique, malar tissues. If brow ptosis or excess eyelid skin is contributing to the individual's aging appearance, a brow lift or blepharoplasty is required to produce the desired result. ^[7]

In addition to cervicofacial skin ptosis, aging brings about other changes. Fine lines and deeply etched wrinkles are problems not well addressed by rhytidectomy. They require ancillary procedures, including chemical and laser exfoliation. The nasolabial fold is not affected by a traditional SMAS facelift; the patient must understand this prior to surgery, and options such as endoscopic midface lifting and deep plane facelifting can be discussed with the patient. ^[8] Discussion of these 2 procedures is beyond the scope of this article. Geniomandibular grooves are similarly not corrected by facelifting. Again, special procedures or implants may be necessary for correction; surgical planning to treat this problem may include pre-jowl chin implants or autologous fat injections. However, a new technique has been studied for filling deep nasolabial folds with SMAS tissue. ^[9]

The overall improvement possible with rhytidectomy is limited by aging of the upper third of the face and eyelids and the presence of wrinkles. When these problems are not addressed, suboptimal results are obtained, leaving half the face appearing aged. The underlying structure of the face is also critical because the redraping of the skin from the facelift highlights attractive cheekbones, chin, and jaw line. A relatively high and posterior hyoid is ideal, allowing maximal elevation of the submental contour.

Patients with rounder faces, low cheekbones, short mandibles, and ptotic submandibular glands have limited cervicofacial definition with rhytidectomy alone. With these patients, adjunctive cheek and chin implantation may be necessary to provide the desired result. Patients with a small chin or inferiorly placed hyoid cannot achieve the desired cervicomental definition without a chin implant.

The authors use a 2-layer cervicofacial rhytidectomy with suspension of the superficial musculoaponeurotic system (SMAS). The SMAS fascia is a fanlike fascia that envelops the face and is used to resuspend sagging facial tissues. The SMAS is continuous with the platysma muscle inferiorly and the superficial temporal fascia superiorly, and it is superficial to the parotid fascia. The SMAS connects to the fascial musculature in the nasolabial, perioral, and periorbital regions.

Facial nerve branches that exit the parotid gland are deep to the SMAS. The frontal branch of the facial nerve is deep to the superficial temporal fascia. Therefore, to avoid injury, the plane of dissection should not be as deep as the temporal fascia.

Age alone should not be used as a criterion to deny a patient surgery because patients in the eighth and ninth decades of life can enjoy up to another 15 years of life. Absolute contraindications include bleeding diatheses and American Society of Anesthesiologists (ASA) classes IV and V. Strong relative contraindications include patients with diseases predisposing to poor wound healing, ie, those with diabetes mellitus, those on long-term steroid therapy, or those with connective-tissue disorders such as Ehlers-Danlos syndrome.

A history of smoking is relevant to preoperative assessment. Rees and Aston noted that people who smoke have 12 times more risk of skin slough than people who do not smoke do. Patients who smoke also have a higher risk of hematoma formation. These effects are believed to be due to increased vasoconstriction and coughing in smokers, respectively. If the patient stops smoking for 1 month before and after surgery, these complications can be limited.

Psychological assessment is as important as the patient's medical status. The surgeon must determine patient motivation and must ascertain whether the patient has reasonable expectations for the surgical outcome. Any psychiatric illness that involves a distorted perception of reality, such as schizophrenia, should be a contraindication to surgery. If any question exists as to whether a patient has a psychiatric illness that may impact the surgical plan, a psychiatric consult is required.