Loose, sagging skin is an unfortunate but often inevitable part of the aging process. These changes are particularly troublesome on facial and neck skin where they result in deep, static rhytides. Traditionally, surgical procedures incorporating skin removal and suspension sutures were utilized to remove the excess skin and reposition the remaining skin to recreate a younger facial structure and appearance. Most commonly these procedures consist of a facelift or necklift, which are often performed together to achieve better results. Due to the increasing epidemic of obesity, and the changes in skin tone and tightness following weight loss, demand for skin tightening of non-facial skin has also increased dramatically in recent years. Although invasive surgical procedures remain the gold standard for large-scale skin tightening and removal, many patients are concerned about the downtime, healing, and cost associated with these procedures. As a result, patients are increasingly turning to noninvasive procedures to tighten their loose skin and minimize the aging process, and cosmetic skin tightening has become a rapidly enlarging field.
There are now multiple noninvasive treatment options to achieve skin tightening. The most commonly utilized technologies include laser, radiofrequency (RF), and ultrasound. These noninvasive treatment options are most appropriate for those patients with mild-to-moderate skin laxity. Patients with significant skin laxity, such as severe jowl formation, are typically better candidates for surgical lifting procedures. Although there are significant differences between these new, noninvasive technologies, in general, their goal is to tighten existing skin via controlled dermal heating to stimulate collagen remodeling and neocollagenesis. There are advantages and disadvantages to each technology, and as a result, no single technology is best for all patients. Furthermore, it is often difficult to predict who will benefit most from one procedure or another. Thus, it is important to be familiar with all of these technologies to be able to offer each patient the treatment that best achieves their cosmetic goals.
It is important to remember that many of the treatments we discuss in this chapter may not be specifically FDA cleared for skin tightening; instead, they may be approved for other uses, such as deep dermal heating or cellulite improvement. Many of the treatments we discuss in this chapter may, therefore, represent off-label indications for these devices. In addition, we will not focus on noninvasive fat contouring technologies in this chapter; these technologies are discussed elsewhere in this book.
BASIC SCIENCE OF COLLAGEN
Aging results in damage to collagen, which manifests itself as fragmentation of the collagen fibers and solar elastosis. This occurs as a result of extrinsic damage such as sun exposure and smoking, as well as intrinsic effects including genetics. Tissue tightening technologies focus on dermal heating to tighten existing, damaged collagen and stimulate neocollagenesis. It is, therefore, important to have an understanding of the basic science of collagen.
Collagen is a triple helical structure, held together ...