Understanding the anatomy and distribution of facial fat and the alterations that occur during the aging process is essential to effectively and precisely achieve facial rejuvenation. Over the past several years, through cadaveric dissections and computed tomographic studies, much has been discovered concerning the adipose tissue of the face and how it influences the dynamic process of aging. Site-specific augmentation with fillers can now be used to refine facial shape and topography in a more predictable and precise fashion. The purpose of this article is to provide an introduction to facial fat compartmentalization along with clinical examples to illustrate how the knowledge of underlying anatomy influences site-specific augmentation.
Key points
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Understanding the anatomy and distribution of facial fat and the alterations that occur during the aging process is essential to effectively and precisely achieve facial rejuvenation.
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Over the past several years, through cadaveric dissections and computed tomographic studies, much has been discovered concerning the adipose tissue of the face and how it influences the dynamic process of aging.
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Site-specific augmentation with fillers can now be used to refine facial shape and topography in a more predictable and precise fashion
Introduction
Our understanding of how the face ages and how to best mitigate these changes, is in a perpetual state of evolution and refinement. Evolving insights into the anatomy of aging are clarifying our understanding of the pathophysiology of aging, the changes in elasticity of the skin, the compartmentalization of facial fat, and the role of bony support and how it changes over time. Seemingly subtle changes over time can have an enormous impact on our perception of a face, making it appear older or younger in an almost imperceptible way. Erasing lines and folds, tightening sagging skin, or restoring young full lips may rejuvenate some faces, but as we are all unfortunately aware, can also look odd and a bit out of perspective on others. Patients new to fillers often bring up fear of this kind of “unnatural” result, causing some to avoid treatments altogether. The restoration of a natural volume distribution is a major goal in facial rejuvenation. Using the evolving knowledge of facial fat anatomy to recognize “what’s been lost where” on a case-by-case basis so as to individualize treatment plans may help us to offer the sort of subtle and natural-looking results desired by many patients (“I don’t want to look done, I just don’t want to look tired”).
The purpose of this article was simply to provide an introduction to some of the recent literature concerning facial fat compartmentalization, along with a few clinical examples that were chosen to illustrate the utility of “site-specific placement” (ie, placing filler in specific fat compartments to obtain specific, predictable, and natural-appearing results). Specific techniques and particular fillers are not addressed here. Additionally, as this article is meant to serve as an introduction to a concept, and not an exhaustive review, more detailed descriptions of this anatomy can be found elsewhere and are referenced in this work.
Introduction
Our understanding of how the face ages and how to best mitigate these changes, is in a perpetual state of evolution and refinement. Evolving insights into the anatomy of aging are clarifying our understanding of the pathophysiology of aging, the changes in elasticity of the skin, the compartmentalization of facial fat, and the role of bony support and how it changes over time. Seemingly subtle changes over time can have an enormous impact on our perception of a face, making it appear older or younger in an almost imperceptible way. Erasing lines and folds, tightening sagging skin, or restoring young full lips may rejuvenate some faces, but as we are all unfortunately aware, can also look odd and a bit out of perspective on others. Patients new to fillers often bring up fear of this kind of “unnatural” result, causing some to avoid treatments altogether. The restoration of a natural volume distribution is a major goal in facial rejuvenation. Using the evolving knowledge of facial fat anatomy to recognize “what’s been lost where” on a case-by-case basis so as to individualize treatment plans may help us to offer the sort of subtle and natural-looking results desired by many patients (“I don’t want to look done, I just don’t want to look tired”).
The purpose of this article was simply to provide an introduction to some of the recent literature concerning facial fat compartmentalization, along with a few clinical examples that were chosen to illustrate the utility of “site-specific placement” (ie, placing filler in specific fat compartments to obtain specific, predictable, and natural-appearing results). Specific techniques and particular fillers are not addressed here. Additionally, as this article is meant to serve as an introduction to a concept, and not an exhaustive review, more detailed descriptions of this anatomy can be found elsewhere and are referenced in this work.
Facial fat compartments
The discovery that facial fat does not exist as one homogeneous object on the face as traditionally thought, but rather as many dynamic compartments that can be evaluated, augmented, and modified, represents a major breakthrough in our understanding of facial aging.
The central role of volume loss and deflation, rather than ptosis alone, in the aging face has been eloquently illustrated by Lambros in a longitudinal photographic analysis of more than 100 patients spanning an average period of 25 years. This invaluable work contributed inspiration to a groundbreaking study done at the University of Texas, Southwestern (UTSW) in 2007, elucidating the compartmentalization of facial fat. Since that time, many subsequent studies from several groups have contributed to this body of knowledge. Pessa and Rohrich recently published a textbook presenting findings from more than 1000 dissections encompassing more than 20 years of work that is an excellent resource on this subject.
The landmark studies by Rohrich and Pessa at UTSW utilized fresh cadaveric anatomic dissections with dye staining for visualization of individual compartments. Fig. 1 shows an image of the superficial fat compartments of the midface from the original study, which revealed the compartmentalization of facial fat in this area. The nasolabial fat compartment is the most medial of the major cheek compartments, followed by the medial and the middle cheek compartments. Subsequent studies revealed that subcutaneous fat, both superficial and deep to the superficial musculoaponeurotic system, is compartmentalized, specifically by fascial extensions that form a framework that provides a ‘‘retaining system’’ for the human face. Implicit in this concept is the suggestion that the face ages three-dimensionally, with separate compartments changing relative to one another by both position and volume.
The superficial adipose tissue has as its boundaries vascularized membranes arising from superficial fascia, whereas deep fat is compartmentalized by nonvascularized fascial boundaries that most likely represent fusion zones of various fascias.
A working hypothesis of facial fat aging is the concept that folds occur at transition points between thicker and thinner superficial fat compartments; in contrast, loss and/or ptosis of the deep fat compartments leads to changes in contour.
Both may play a role in facial shape, as illustrated by the remaining figures.
Upper face
Fig. 2 shows an image of the lateral temporal cheek fat. The superior and inferior temporal septa (STS and ITS) represent the superior and inferior boundaries, respectively. The temporal fat extends beyond the hairline. This compartment spans the forehead to the cervical region. It is the most lateral of the cheek fat compartments and has an identifiable septal boundary medially called the lateral cheek septum. (The nasolabial cheek compartment is stained in this image as well. Note the difference in the size of this compartment in this cadaver as opposed to the size of the same compartment in the cadaver pictured in Fig. 1 .) The clinical photographs in Figs. 3 and 4 show women who have lost fat in different areas of this compartment with aging. The woman in Fig. 3 A has lost temporal fat beyond her hairline, changing the shape of her face to a “peanut” shape, which is restored to an oval with volume augmentation in this area. The woman in Fig. 3 B has lost temporal fat at the superior border, resulting in a somewhat harsh skeletonized appearance that softens with volume augmentation in that area.
The patient in Fig. 4 has ample temporal volume, but an absence of lateral cheek fat, giving her lateral face a concave (almost “horselike”) appearance that is softened as her face is ovalized by treatment in this area. Note that the tragus is visible in an anterior view in a patient without much lateral cheek fat and is less visible when this area is full (this is often seen in thin patients after facelifting).
Augmenting specific areas has a specific effect and enables the clinician to tailor his or her treatment based on the individual’s particular morphology.
The most recent advance in the visualization of these compartments is the use of a novel technique using a thin-slice computed tomographic (CT) scan with an iodinated contrast medium. This method allows for a reproducible three-dimensional (3D) depiction of the compartments that can be used for detailed investigations regarding the shape, size, and volume of the distinct fat compartments.
An additional advantage of the use of radiopaque dye with CT is that it allows compartments to be visualized from any plane. Gierloff and colleagues, authors of the first study using this novel technique, studied 12 cadavers divided evenly into younger (59–75) and older (76–104) age groups. They presented evidence that is in concordance with what has been observed in the cadaveric dissection and dye sequestration studies; a schematic from their article depicting the superficial fat compartments of the midface is shown in Fig. 5 .
In 2007, Rohrich and Pessa determined, via dye injection into cadaveric heads, that there are 3 fat compartments of the forehead. The central compartment is located in the midline and extends inferiorly to the nasal dorsum and laterally to a border that they refer to as the “central temporal septum.”
Fig. 6 A shows an image of the central forehead compartment in 3D from the Gierloff and colleagues CT study. The forehead is a key area of facial expression. Note in Fig. 6 B and C that site-specific augmentation of this particular fat pad reduces the perceived look of anger in this patient.
