Addressing Facial Shape and Proportions With Injectable Agents in Youth and Age

History and Introduction

As noted by Pessa, “there are many arbitrary definitions of what constitutes a youthful face but the appearance of youth is not arbitrary; it is simply difficult to define” . In an effort to solve any problem, one must first define the problem, come up with a solution, and then successfully execute the solution. The progression of facial shape with aging is the subject of many theories and hypotheses, but much remains to be understood. Current understanding of the facial aging process remains largely empirical, given that it has traditionally been based on the effectiveness of various treatments aimed at rejuvenation, some resulting in an odd or “done” appearance. Defining the problem has proved challenging, as facial aging is a complex process that is the cumulative effect of simultaneous changes of the many components of the face, as well as the interaction of these components with each other.

A growing understanding of this complex process has been ongoing in the world of surgery and surgical techniques since its inception, and has informed and driven the change from an empiric approach to an anatomic one, enabling improved and more natural-appearing results. Fig. 3.1 , adapted from an article on facial aging from Cotofana et al., provides an impressive illustration of how innovation and advances in technology, which have given us newer and faster ways to both gather and share information, are accelerating our understanding of facial anatomy . As a result our understanding of the anatomic changes observed in the aging face has progressed considerably over the last couple of decades, leading to a paradigm shift in the way we both perceive and approach these changes. The answer to the question of whether we sink or we sag has become a “yes” to both, as we begin to see aging as a complex and interdependent interplay between all structural layers culminating in the collapse of a three-dimensional (3D) construct. Newer understanding of volume loss as a critical component of facial aging and the integration of volume replacement into the surgical and nonsurgical therapeutic algorithm is arguably the most significant recent development in the field of facial rejuvenation. The ability to accurately recognize where volume has been lost (or sometimes lacking in the first place) in each individual at a given point in time will greatly enhance our ability to address the loss with site-specific corrections in order to achieve optimal and natural-looking results. However, most of us would agree with Glasgold that the recent rapid and widespread adoption of “off the shelf” volume replacement has outpaced a sophisticated understanding of its goals, resulting in a new and different, but equally undesirable category of “looking done” .

So the problem can be defined as the attainment of natural-looking results in the rejuvenation of the aging face, and the solution to that problem, as well as its execution, lies in understanding its pathogenesis, which is anatomic. Recent insights and gains in our anatomic understanding enhance our current ability to come closer to this goal. For this reason, this chapter is not written on the various types of fillers or techniques of filler injection, about which much has been written, but rather on how to decide where to use it and why in different faces, using anatomy as a guide. This approach is rational, practical, teachable, and reproducible, as it is simply the result of the recognition, and targeted correction, of currently recognized specific anatomic deficiencies. Using this approach has improved my results and resulted in much higher patient satisfaction. That said, it is not the only way. Many other approaches have been employed successfully (using specific landmarks or masks or phi ratios, for example), in order to obtain pleasing results; however, some aspects of these approaches also use anatomy. The purpose of this chapter is to provide an introduction and brief summary of some of the recent literature concerning facial anatomy and the anatomy of facial aging, which serve as the basis and foundation for predictable, specific, reproducible, and natural-appearing results with the use of injectables. This summary of current concepts will be presented along with clinical examples exhibiting primarily congenital absence or aging changes in the tissue layer discussed in order to better illustrate the discussion. The practical use of these concepts in injectable treatment of the face will then be illustrated using a number of case reports of patients of different ages, gender, and ethnic backgrounds along with a short description of where each face was treated and why, using both a layered anatomic (tissue structures) and regional approach (upper, mid, and lower face, shape, proportions). In order to look at a number of cases, as well as to compare and contrast different faces, these cases are presented in a “composite” format. This smaller format additionally makes it easier to recognize facial shape and proportions, and to determine what is present or missing that may be moving the face away from the ideal shape and proportions, which will be discussed below.

Finally, as aging is a complex multimodal process, multimodal therapy must be used to address it. Despite the widespread popularity of injectable treatments as an “immediate gratification no downtime option,” they have their limitations and risks like everything else, and are not a panacea (or stand alone) treatment of the aging face.

Personal Philosophy

Although a new patient may present pointing to a wrinkle, line, or fold they have noticed seemingly overnight, as stated above, we are now increasingly aware that these first obvious signs of aging noted by the patient are in fact downstream markers of a slow progressive change taking place in all structures of the face. This represents a paradigm shift in our current approach to facial rejuvenation. This concept will be addressed, discussed, and illustrated in this chapter.

Facial beauty and attractiveness are important cross-cultural social concepts as they tend to dictate how individuals are judged and treated . Research has shown that facial beauty is perceived and processed rapidly by the brain, and this perception biases subsequent cognitive processes . A recent extensive review of research on facial beauty determined that four characteristics emerge as the most statistically significant determinants of attractiveness: averageness (prototypicality), sexual dimorphism, youthfulness, and symmetry .

Not surprisingly, all of these have something to do with optimizing mate selection. Youth and sexual dimorphism are obvious. Prototypicality likely signifies a good mix of genes (avoiding autosomal recessive disease), while symmetry may indicate a history of maternal stability and health during development. Additionally, changes seen with aging may lead to an unintended and undesirable misinterpretation of mood by others that is unwelcome to most all of us as we age and is one of the most common presenting complaints, i.e., “I don't mind getting older I just don't want to look mad, sad, and tired.” This can often be remedied with glabellar neuromodulators as well as fillers infraorbitally as well as around the mouth, resulting in a surprisingly different first impression of a face, as seen in Fig. 3.2 . Looks matter because they can have a great impact on quality of life.

Facial Anatomy: Introduction and Overview

The traditional approach to assessing the face is to consider the upper, middle, and lower thirds, regionally. Other newer useful approaches using structural layers or functional differences reflect our recognition that the pathogenesis of facial aging is a multifactorial process that can be explained on an anatomic basis, and likely accounts for the variations in the onset and outcome of aging seen in different individuals. We will look at the face with these different approaches in the next section. Regardless of approach, cumulative changes in all structural tissue layers of the face with time lead to a change in the morphology of the entire face in terms of its shape, proportions, and topography. Morphologic changes seen in women from different decades of life (30s to 60s) are illustrated in Fig. 3.3 . Although these types of figures were initially used to visualize the differences in the depth of a tear trough (TT), nasolabial fold (NLF), or marionette line with advancing age, they can now be appreciated as evidence that these folds and lines are downstream markers of a global change rather than isolated entities. This figure also illustrates how changes in facial topography seen with aging sharpen the once smooth transition between anatomic units, by greatly magnifying light reflection and/or shadow. This concept is critical to our understanding, as seemingly subtle changes in light and shadow over time can have an enormous impact on our perception of a face in an almost indiscernible way. The rationale behind restoring 3D contours to the face as it ages, whether by lifting, tightening, or volume restoration, is easy to appreciate when looking at photographs illustrating how aging takes us from 3D to 2D, as shown in the woman in Fig. 3.4 shown at college graduation and 30 years later, both before and after injectable treatment. The youthful oval face dramatically flattens with age, and restoration of previous arcs and convexities restore youthful light and shadow patterns.

Although the sequence of events observed in aging is somewhat predictable, its pace among individuals is variable and progresses in each person from a unique starting point. Additionally, changes in different tissue layers within a single individual occur interdependently. The lack of, or loss, of structural integrity in one area may worsen the appearance of a neighboring area. Conversely, the presence, or restoration, of structural integrity in one area may improve the appearance of a neighboring area .

We know that almost all faces develop with slight asymmetry following development of the neural tube embryologically, and the aforementioned concept can be readily appreciated when looking at the facial asymmetry in the woman in Fig. 3.5 who appears more aged on her right, “sunken,” side compared with her fuller left side. Note that the less volumized side (right) of her face shows a clear delineation of her temple, lid, and cheek as separate entities, while the more volumized side (left) does not—one area seems to blend seamlessly with another, reflecting light uninterrupted by the shadows seen on the right. Note that the amount of volume loss with aging on the initially smaller right side has now resulted in an outer skin envelope slightly too large for its now “smaller” face, and contributes to a more pronounced ptosis and loss of jawline contour on this side earlier than on the left side (which commonly has more solar elastosis because its the driver's side window). Less bony support and soft tissue leads to a lower brow position, leading to lid lag laterally and an early hollowing “A-frame” deformity somewhat camouflaged by a slackened upper lid. A TT and lid-cheek junction are seen only on the less volumized side. There is also less anterior and lateral cheek projection, a slightly deeper nasal sulcus, a longer upper lip, and an increased mental hollowing on the less volumized side, whereas no such demarcation is visible on the more volumized side. This combines to make the perioral proportions in the lower third of her face look slightly less youthful on the less volumized side. Finally, the peripheral contours on the less volumized side of her face are more abrupt than those on the fuller side. The convexity of the temple and the preauricular volume on the full side lends an overall oval shape to that side of her face that is lost due to the atrophy on the right. Compare this with the ideal proportions of a youthful face, as shown in Fig. 3.6 , depicting a width of five eyes across in vertical fifths and an equal volume in the upper, mid, and lower face when measured in horizontal thirds. Additionally, this schematic depicts the golden phi ratio of 1:1.6 in the perioral region of the lower third of the face. Note that the fuller side of the face in Fig. 3.5 is closer to these ideal proportions, providing a “roadmap” of where to revolumize the other side.

Over a decade ago, in an effort to visualize the aging face in linear examples, Lambros used computer animation to compare current photographs of patients matched for light and position with photographs taken 10 to 50 years previously to gain insight into midfacial aging, showing that deflation can mimic descent . Recent work by Lambros and Amos now provides an invaluable tool to visualize the facial aging process using 3D facial averaging . They have published animations made from 3D facial images amassed over the past 10 years, using a 3D camera system (Vectra; Canfield Scientific, NJ, USA). These are shown as static images in Fig. 3.7 . The image on the left shows the average of the 3D facial surfaces of 116 female subjects aged 20 to 30 years, and the image on the right shows the average of the 3D facial surfaces of 100 female subjects aged 68 to 91 years. The static images illustrate the differences seen in the morphology of the younger and older averages well; however, this image may be viewed in animation online at http://links.lww.com/PRS/B922 . It is interesting to compare the similarities between the youngest and oldest women in Fig. 3.3 to the 3D-averaged image of similar age. Look at the shape of the orbits, the bony support under the brow and the nose, the flattening of the midface and lateral cheeks, and the change in proportions in the lower third of the face. Note how the TT and NLF deepen as the craniofacial support changes and the cheek flattens. Look at the eversion versus inversion of the lips. Look at light and shadow, and how it plays off areas of depression and prominence (convexities and concavities) in both the younger and older face. Do not focus on just “lines and folds,” but consider all the structural changes in the face. Consider the interdependency between them by treating the whole face as a 3D interlocking puzzle where losing or correcting one component may have a negative or positive impact on another.

Facial Anatomy and Aging: Regional Thirds of the Face

The traditional regional approach to assessing the face is to consider the upper, middle, and lower thirds (as shown in Fig. 3.6B ). Glasgold, Glasgold, and Lam have greatly increased our appreciation that a detailed examination of the shadows and shadow patterns that develop in all areas of the face with volumetric facial aging will lead to a better understanding of how to apply volumetric techniques to create a natural-appearing result. Although they have worked mostly with fat augmentation, the same concepts apply to filler (although filler may not be a cost-effective option for those needing a lot of volume) . Although every face is unique, the shadows that develop as we age are consistent. Not everyone develops every shadow, but the typical shadows of aging are universal. Glasgold notes the ease with which an artist can depict an aging face with a few shadow strokes makes this con­cept easy to grasp. Studies documenting the consistent patterns of volume loss in the aging face are reviewed in the following sections. The skin of the face has consistent attachment points to the underlying structures through the facial retaining ligaments, and as the volume of the face deflates, these attachment points will define most of the shadows that develop with age . Advancing age accounts for specific areas of volume loss in all thirds of the face. These changes in each third of the face are summarized here, paraphrasing the (“can't be improved upon”) descriptions published by Glasgold, Glasgold, and Lam. Compare characteristics of younger and older faces as you read through these by looking again at the women pictured in Figs. 3.3, 3.4, and 3.5 and the averages of the 3D facial surfaces in Fig. 3.7 .