Lip Augmentation

Introduction

The lips are a defining feature of youth and beauty. With the increasing cultural emphasis on youth and beauty, full lips are aesthetically desired because they are considered youthful. Although they may represent a small portion of the face based on size, they can have a substantial effect on a person's overall appearance. Unfortunately, as we age, lips undergo some of the most dramatic changes of the entire face. These changes are a natural part of the aging process, but they can be softened or reversed to give a more youthful and rejuvenated appearance. Understanding the normal process of aging and the anatomy and variations in anatomy, managing patient expectations, and taking into account patient’s unique facial features and their ethnic racial background will create a pleasing outcome and achieve optimal cosmetic results.

The Aging Process on the Lips

Although this chapter will focus specifically on the rejuvenation of the lips, it is important to consider the lips in the larger context of the perioral region, demarcated by the nasal base, cheeks, chin, and framed by the masseter muscle. Patients may have thin lips at baseline or progressively thin as part of the well described aging process. Pouty full lips are usually synonymous with youth, while the loss of these features attribute to the overall aging appearance of the face.

There are a multitude of causes and effects of the aging process in the lower face. It is important to consider the following aging changes that contribute to lip size and position: maxillary bone resorption, increased prominence of the pyriform fossa, and mandibular bone resorption. With the former, there is an associated alveolar tooth loss and loss of the maxillary arch, causing posterior displacement of the nasal base and upper lip. Additionally, there is a loss of elevator muscles and soft tissue, resulting in redundancy, which causes increased upper lip length and loss of anterior projection of the upper lip. With mandibular bone resorption, this leads to loss of support of the lip depressors, which inevitably causes less lower lip show and decreased incisor show. In addition to intrinsic aging, ultraviolet radiation can cause photoaging of the skin, resulting in mottled dyspigmentation and irregular texture. Collagen fibers diminish, elastic tissue is degraded, and there is a loss of subcutaneous fat and bone. These changes result in an overall drooping of the perioral region, which may call attention to the lips. Therefore, to truly rejuvenate the lips, it may be necessary to address the entire perioral region, including the nasolabial folds, melomental creases, and chin. These topics are covered elsewhere in this book but should be considered in any cosmetic consultation.

The lips specifically are dramatically redefined by an overall loss of lip volume and structure throughout the aging process: the upper lip becomes thin and elongated, and the lower lip becomes thin and rolls inward. There is blunting of the appearance of the pink vermilion of the lip and a sagging of the corners of the mouth, which is further accentuated by the activity of the depressor anguli oris muscle. Sagging in the perioral region causing descent of the upper mouth over the bottom lip can result in an entity named “lateral lip festoon.” The overall result is a loss of show of the upper teeth, with an increase in the show of the lower teeth. The Cupid's bow—the area defined by the two high arched points of the upper lip—becomes effaced and flattened; the two philtral columns of the upper lip also loose definition. Over time, the beautiful, defined, arched structure of the upper lip is lost, and in its place a thin, poorly defined upper lip develops. In conjunction with the overall loss of lip volume, there is also the chronic effect of activity of the orbicularis oris muscle, leading to the formation of radiating deep perioral rhytides. Patients often complain that these rhytides cause “bleeding lipstick” lines and are a frequent issue of discussion in cosmetic consultations. Given that the aging process is multifactorial, the goal of lip rejuvenation includes diminishing fine lines, diminishing length of the upper lip, redefining the Cupid’s bow and vermilion border, eversion of the vermilion, and improving the volume within the oral commissures that may contribute to the “lateral lip festoons.”

Multiple assessment scales have been developed to quantify these changes. Validated scales include the 5-point Medicis Lip Fullness Scale (MLFS) by Carruthers et al. ( Fig. 25.1 ), the five-point Allergan Lip Fullness Scale by Werschler et al., the Perioral Lines at Rest (POL), Perioral Lines at Maximum Contraction (POLM) and Oral Commissures Severity (OCS) scales by Cohen et al., the facial fold assessment scale by Narins et al., the Catherine-Knowles-Clarke (CKC) scale by Downie et al. ( Table 25.1 ), and the photonumeric grading scale for assessing lip volume and thickness by Rossi et al. These scales may be of benefit in the initial assessment of patients and their clinical improvement following lip augmentation.

When done well, lip augmentation and rejuvenation can dramatically address many of these changes associated with aging lips to both replace the volume loss and redefine the lip structure. Numerous studies have shown that for a majority of patients, injection of HA fillers to the lips produces significant improvement in lip fullness and investigator- and patient-assessed global appearance (via the Global Aesthetic Improvement Scale [GAIS]).

However, in some cases, simply injecting soft tissue fillers into the lips alone may not achieve the best results. Low-dose botulinum toxins around the lips may improve perioral rhytides, whereas botulinum toxin injections into the depressor anguli oris muscles may reduce the down turning of the oral commissures and enhance the longevity of the fillers. In addition to soft tissue fillers, the “lip flip”—where botulinum toxin is injected at the vermilion border—has been shown to improve lip contour, eversion, and fullness. However, although reported in the literature, these are off-label uses of botulinum toxin not approved by regulatory authorities, such as the US Food and Drug Administration (FDA), Health Canada, or European regulatory authorities. In severe cases, resurfacing of the perioral skin with lasers or chemical peels may be necessary. Although this chapter will focus on the use of soft tissue fillers, in many cases, a multimodality approach may be beneficial for patients to achieve optimal rejuvenation.