Facial Aging

Facial aging is associated with a gradual thinning of the skin and loss of elasticity over time accompanied by the diminishment of dermal collagen, hyaluronic acid, and elastin. Ultraviolet (UV) radiation from sun exposure accelerates this process at a higher rate than does chronologic aging. This UV aging process is termed photoaging. To appreciate the contribution of photoaging to the appearance of aged skin, one needs only compare photoprotected skin, such as skin on the inside of the upper forearm or under the chin, to the appearance and texture of skin on face and back of the hands. Photoaged skin typically exhibits the following changes (Figure 19-1 for a computer-enhanced image demonstrating these signs)⁵:

FIGURE 19-1 Photoaging changes (computer-enhanced image).

(Copyright Rebecca Small, MD.)

In a study by New York plastic surgeon Dr. D. Antell on aging in identical twins, extrinsic factors, such as prolonged sun exposure, resulted in advanced aging changes (Figure 19-2A) relative to the intrinsic aging seen in non–sun-exposed twins (Figure 19-2B).⁶ Habitual facial expressions also contribute to formation of visible lines and wrinkles, particularly in the upper one-third of the face, because repetitive muscle contractions etch in frown lines between eyebrows and crow’s feet radiating from the corner of the eyes. In addition to skin laxity, volume loss, and dynamic musculature, facial aging also results from biometric facial changes such as descent of malar fat pads, which contributes to deepened nasolabial folds, and resorption of maxillary and mandibular bone, which contributes to radial lip lines and mental crease formation.^7,8

FIGURE 19-2 Facial aging differences in identical twins. Advanced photoaging changes of (A) skin wrinkling and laxity with prolonged sun exposure and (B) mild changes with minimal sun exposure.

(Courtesy of Dr. D. Antell, New York City, www.Antell-md.com.)

Skin Anatomy

The skin is divided into three layers: the epidermis, dermis, and hypodermis or subcutaneous layer (Figure 19-3). The epidermis is the top layer of the skin and is composed of four cell types: keratinocytes, melanocytes, Langerhans cells, and Merkel cells. The epidermis is further divided into the outermost nonliving layer, the stratum corneum, and the living cellular layers of the stratum granulosum, stratum spinosum, and stratum basale.

FIGURE 19-3 Skin anatomy.

(Modified from White CR, Bigby M, Sangueza OP. What is normal skin? In: Arndt KA, LeBoit PE, Robinson JK, Wintroub BU, eds., Cutaneous Medicine and Surgery. Philadelphia: Saunders; 1996:3–41.)

The stratum corneum is composed of corneocytes and lipids, which serves as a barrier against microbial pathogens and environmental irritants and also keeps the skin hydrated and protected from injury. Constant renewal is necessary for the epidermis to maintain its integrity and function effectively. In healthy young skin, it takes approximately 1 month for keratinocytes to migrate from the living basal layer of the epidermis to the stratum corneum surface and desquamate, during the process of epidermal renewal. Figure 19-4 shows the structure of the epidermis with the keratinocyte maturation highlighted. Photoaged skin demonstrates slower keratinocyte maturation and abnormal retention of cells in the epidermis. This results in a rough and thickened stratum corneum with impaired barrier function, reduced hydration capabilities, and increased pigmentation from retention of melanin-laden keratinocytes in the epidermis.

FIGURE 19-4 Epidermis structure showing keratinocyte maturation process from basal keratinocyte to desquamating corneocyte.

The distribution of melanin within the epidermis determines skin coloration. While the number of melanocytes is similar for both light and dark skin types, melanin is concentrated in small aggregated melanosomes in light skin and is more disbursed in darker skin.⁹

The dermis lies beneath the epidermis and is divided into the more superficial papillary dermis and deeper reticular dermis. The main cell type in the dermis is the fibroblast, which is more abundant in the papillary dermis and sparse in the reticular dermis. Below the dermis and above the underlying muscle is the subcutaneous layer, also called the hypodermis, subcutis or superficial fascia. This layer has both fatty and fibrous components.

Aesthetic Consultation

Aesthetic consultation is an important part of successfully performing aesthetic treatments. The patient’s medical history is reviewed, including past medical history, medications, allergies, and past cosmetic history (including results from previous treatments and side effects if any, surgeries, and satisfaction with outcomes). Figure 19-5 is an example of an aesthetic intake form that clinicians may use. Repeated dissatisfaction with past aesthetic treatments can be associated with unrealistic expectations or body dysmorphic disorder and is a contraindication to treatment.

FIGURE 19-5 Aesthetic patient intake form.

The main areas of concern should be determined and prioritized by the patient at the time of consultation. It is recommended that the patient view these areas using a handheld mirror, so that the provider and patient may simultaneously examine the desired treatment areas. Asymmetries, such as uneven eyebrow height, are pointed out to the patient, noted in the chart, and photographed.¹⁰ Pigmented lesions in the treatment area are evaluated and lesions suspected of melanoma biopsied with results reviewed prior to proceeding with treatments.

Early on in the consultation process, providers should assess whether patients will benefit most from surgical intervention, or if minimally invasive treatments will address their concerns adequately particularly for patients presenting with severe wrinkles and excessive skin laxity. Treatment options and recommendations should be discussed along with anticipated results, risks of side effects and complications, recovery time, and costs. Based on this discussion, an individualized aesthetic rejuvenation treatment plan is created.

Baseline assessments of the patient’s skin type and severity of photoaging are typically performed at the time of consultation using the Glogau classification of photoaging and Fitzpatrick skin type classification, respectively, as discussed next.