Skin aging is a multifaceted process that involves intrinsic and extrinsic mechanisms that lead to various structural and physiological changes in the skin. Intrinsic aging is associated with programmed aging and cellular senescence, which are caused by endogenous oxidative stress and cellular damage. Extrinsic aging is the result of environmental factors, such as ultraviolet (UV) radiation and pollution, and leads to the production of reactive oxygen species, ultimately causing DNA damage and cellular dysfunction. In aged skin, senescent cells accumulate and contribute to the degradation of the extracellular matrix, which further contributes to the aging process. To combat the symptoms of aging, various topical agents and clinical procedures such as chemical peels, injectables, and energy-based devices have been developed. These procedures address different symptoms of aging, but to devise an effective anti-aging treatment protocol, it is essential to thoroughly understand the mechanisms of skin aging. This review provides an overview of the mechanisms of skin aging and their significance in the development of anti-aging treatments.

The aging process is a complex interplay of intrinsic and extrinsic factors across multiple layers of the face. Accordingly, combining aesthetic interventions targeting different manifestations of aging often leads to better results than single modalities alone. However, no guidelines for a pan-facial approach using multiple interventions have been published to date. To develop consensus recommendations for the optimal combination and ideal sequence of botulinum toxin (BoNT), hyaluronic acid, calcium hydroxylapatite, and microfocused ultrasound with visualization (MFU-V) in persons of all Fitzpatrick skin types. Fifteen specialists convened under the guidance of a certified moderator. Consensus was defined as approval from 75% to 94% of all participants, whereas agreement of ≥95% denoted a strong consensus. Optimal aesthetic treatment of the face begins with a thorough patient assessment and an individualized treatment plan. Spacing consecutive treatments 1 to 2 weeks apart allows for resolution of side effects and/or to assess results. For same-day treatments, BoNT and fillers may be performed together in either sequence, whereas MFU-V is recommended before injectable agents. Expert consensus supports a combination approach using multiple modalities in specific sequence for the safe and effective treatment of the aging face.

Surgical scars are a common cosmetic problem that occurs in various surgical fields including dermatology. Diverse trials have been made to prevent this annoying scar formation. Recently, 585- and 595-nm pulsed dye laser irradiation presented satisfactory cosmetic outcome for the treatment of surgical scars. Other fractionated lasers or light devices were also applied for scar treatment. To determine the effectiveness and safety of a newly developed 1,550-nm fractional erbium-glass laser in the prevention of scar formation after total thyroidectomy. Twenty-seven ethnic South Korean patients with linear surgical suture lines after total thyroidectomy operation were treated with a 1,550-nm fractional erbium-glass laser. The same surgeon performed all of the operations using the same surgical techniques. Each patient was treated four times at 1-month intervals using the same parameters (5- x 10-mm spot size, 10 mJ, 1,500 spot/cm(2), static mode). Initiation of the first irradiation was made approximately 2 to 3 weeks after the thyroidectomy. The scar prevention effects were evaluated each month for 6 months after thyroidectomy. Two kinds of assessment methods were applied in this evaluation. First, the Vancouver Scar Scale (VSS) was used. Second, three independent physicians gave a global assessment valuation to the final cosmetic results: poor (1), fair (2), good (3), or excellent (4). These results were compared with the surgical scars of a control group (patients who denied laser treatments and had no other treatments during the 6 months after total thyroidectomy by the same surgeon). The average VSS score was lower in the laser treatment group. The global assessment also presented better cosmetic outcomes in the treatment group than in the controls. A new 1,550-nm fractional erbium-glass laser may efficiently repress the formation and hypertrophy of thyroidectomy scars on the neck, and it can be safely applied in relatively dark Asian skin without noticeable adverse effects.

Although the use of filling agents for soft-tissue augmentation has increased worldwide, most consensus statements do not distinguish between ethnic populations. There are, however, significant differences between Caucasian and Asian faces, reflecting not only cultural disparities, but also distinctive treatment goals. Unlike aesthetic patients in the West, who usually seek to improve the signs of aging, Asian patients are younger and request a broader range of indications. Members of the Asia-Pacific Consensus group-comprising specialists from the fields of dermatology, plastic surgery, anatomy, and clinical epidemiology-convened to develop consensus recommendations for Asians based on their own experience using cohesive polydensified matrix, hyaluronic acid, and calcium hydroxylapatite fillers. The Asian face demonstrates differences in facial structure and cosmetic ideals. Improving the forward projection of the "T zone" (i.e., forehead, nose, cheeks, and chin) forms the basis of a safe and effective panfacial approach to the Asian face. Successful augmentation may be achieved with both (1) high- and low-viscosity cohesive polydensified matrix/hyaluronic acid and (2) calcium hydroxylapatite for most indications, although some constraints apply. The Asia-Pacific Consensus recommendations are the first developed specifically for the use of fillers in Asian populations. Therapeutic, V.