Background

The layers of the face encompass the skin; the underlying soft tissues, including the fat (subcutaneous and deep); the mimetic muscles (superficial and deep); the investing fascia, which is known as the superficial muscular aponeurotic system (SMAS); the retaining ligaments; and the skeletal structural support system (bones, cartilage, and teeth).4,18 The soft tissues of the face will naturally descend with age, which will result in progressive laxity and ptosis of the skin, the subcutaneous tissue, the fat, and the fascia (i.e., the SMAS–platysma layer) as well as the retaining ligaments. The facial fat (subcutaneous and deep) may either atrophy (i.e., as a result of resorption) or hypertrophy (i.e., increase in volume), and it is also affected by gravity over time. Facial aging is dynamic and cumulative, and it is also affected by hormonal and degenerative changes in the soft tissues. An understanding of the pertinent biochemical and histologic changes that tend to occur in the facial soft tissues with age and through environmental exposures is an important aspect to consider when developing a reconstruction and rejuvenation treatment plan.

Soft-tissue aging is affected by genetic aspects, hormonal changes, and environmental influences. For some individuals, the deeper soft-tissue envelope remains well preserved while the superficial surface of the skin appears weathered. For others, the surface skin remains youthful while the deeper soft-tissue envelope loses structural landmarks with cutaneous laxity. Extrinsic (environmental) forces that are working on the skin include dehydration, inadequate nutrition, temperature extremes, traumatic influences, chronic exposure to strong ultraviolet sunlight, toxins (e.g., cigarette smoke), and gravity. The intrinsic (genetic) effects have to do with the individual’s basic soft tissues and their skeletal morphology.15,73 Environmental (extrinsic) factors primarily result in dysplasia and structural alteration of the dermal and epidermal layers of the skin, whereas intrinsic (genetic) effects on the skin may result in atrophy and the loss of structural dermal and epidermal components.^19,20,29,84 An individual’s hormone levels throughout life are also known to have significant effects on the aging process.³⁰ Aging is associated with declining levels of several hormones, and it is gender dependent. It is known that, in women, declining estrogen levels are associated with cutaneous changes, many of which can be reversed or improved via estrogen supplementation. Studies of postmenopausal women indicate that estrogen deprivation is associated with dryness, atrophy, fine wrinkling, poor healing, and hot flashes.^30,60 Epidermal thinning, declining dermal collagen content, diminished skin moisture, tissue laxity, and impaired wound healing have been reported among postmenopausal women. The soft-tissue effects of changing hormonal levels with age in males are less well studied but presumed to be of equal importance. The cumulative intrinsic (genetic) effects on the skin can be seen histologically as epidermal thinning, changes in the morphology of the keratinocytes, and a decrease in the number of Langerhans cells and melanocytes. Environmental (extrinsic) aging effects on the skin result in keratinocytic dysplasia and the accumulation of solar elastosis, and they can result in cutaneous carcinogenesis (e.g., basal cell carcinoma, melanoma, squamous cell carcinoma).

All individuals experience some degree of both extrinsic (environmental) and intrinsic (genetic) aging simultaneously (Fig. 40-1). The genetic variability of an individual’s skeletal framework and the degree and pace of soft-tissue aging in each tissue layer makes a uniform template for facial rejuvenation impractical. Visually, as the intrinsic and extrinsic aging of the skin progress, there will be pigmentary abnormalities, wrinkles (rhytids), and texture irregularities that may result in a “weathered” appearance. Current thinking about aging also involves the concept that the gain or loss of fat volume within the deep compartments leads to changes in the shape and contour of the face.²⁰ By contrast, soft-tissue folds occur at the transition points between the thicker and thinner superficial fat compartments. The transition points cause nasolabial folds, labiomental folds, submental creases, and preauricular folds.^65,67 In the upper third of the face, around the eyes, researchers have found that suborbicularis oculi fat is composed of two distinct anatomic compartments: the medial limbus and the lateral canthus region. These researchers have also confirmed that the lateral suborbicularis oculi fat extends from the lateral canthus to the lateral orbital thickening.⁷ The deep medial cheek fat is the most medial of the periorbital deep fat compartments.⁵¹ In current clinical practice, periorbital rejuvenation relies more on soft-tissue augmentation and rearrangement than on tissue removal. In the midface, progressive skin laxity is often combined with the resorption of subcutaneous fat and gravitational effects to result in characteristic changes in the soft-tissue envelope.⁶⁵ In the lower third of the face, there may be ptosis of the chin soft tissues, a loss of the delineation between the jawline and the neck, the development of characteristic jowls, and looseness in the neck skin (which, in the extreme, is characterized as resembling a “turkey gobble”). In many individuals, prominent vertical platysma bands develop in the submental region, and there is often fat hypertrophy in the submental and submandibular regions. These aging effects further hide or eliminate an otherwise attractive and youthful neck–jaw angle.

Frequent Soft-Tissue Facial Aging Characteristics

Basic Principles of Midface and Neck Aging and Rejuvenation

Traditional Face-Lift Approach to Rejuvenation

Face lifting was first performed during the early 1900s and involved skin incisions around the ears, limited skin-flap undermining, and then skin excision before wound closure. In 1859, Gray defined a unique deep layer of tissue just below the facial skin that was described as “superficial subcutaneous fascia.” Not much changed until the 1970s, when both Tessier and Skoog independently described the aesthetic benefit of manipulating this superficial subcutaneous fascia as a separate component during face lifting for rejuvenation purposes. The superficial subcutaneous fascia was recognized as investing the platysma muscles and fusing to the parotid fascia as the facial extension of the cervical investing fascia. It later came to be called the superficial muscular aponeurotic system or SMAS, as mentioned previously.⁴⁸ The SMAS envelopes the platysma muscles within the neck and the lower cheek region. Superiorly, it terminates as the investing layer of the superficial mimetic muscles. Laterally, it fuses with the parotid capsule. Superiorly, it passes over the zygomatic arch to join the temporoparietal fascia. Tessier and Skoog were the first to include as part of the face-lift technique not just the undermining and excision of the skin but also the management of the so-called SMAS–platysma layer. This required unique incisions, undermining, redraping, and tightening of the SMAS–platysma as part of the face-lifting procedure. Since the initial contributions of Tessier and Skoog, every conceivable recommendation has been made by surgeons for dissecting, undermining, excising, adding to, or removing virtually all of the tissue layers and cell types in the head and neck to further enhance the aesthetic outcome.^{2–5,8,18,21,31,47,50,59,77,78} Many of the “innovations” in the area of face lifting have proven to have little additional long-term value, and some have resulted in increased complications and prolonged recoveries. This was confirmed by Chang and colleagues in a recently completed systematic review and comparison of efficacy and complication rates among a variety of face-lift techniques. The authors conclude that there are pros and cons to each of a variety of face-lift techniques and that there is no clear evidence that one is routinely superior to another.⁹

A well-designed traditional face lift often confers much benefit to the jowls (i.e., the mandibular line) and the neck (Figs. 40-5 through 40-10). It can be an effective way to soften the nasolabial folds, to lift the jowls back into the face, to relieve the platysmal bands, to remove the loose skin and excess fat of the neck, and to restore the neck–jaw angle back to its baseline. This can change the overall facial shape from rectangular back to that of a heart in a way that no other soft-tissue treatment modality can provide. The basic traditional face-lift approach requires the consideration of the following:

Anterior Neck (Submental) Approach to Rejuvenation