Is Adding Volume Enough to Treat Facial Sagging? An Anatomical Assessment of Facial Aging II
The full text of my column published in the August 2025 issue of D&PS.
Every treatment and device used to rejuvenate an aging face aims to reverse age-related changes. The aesthetic goals differ by region:
- Temporal zone: improve temple hollowing and descent of the outer eye corners
- Cheek and infraorbital zone: improve midface hollowing, under-eye wrinkles, and enlarged pores
- Parotid zone: improve cheek hollowing and marionette lines
- Jawline zone: define the jawline and improve cheek sagging
- Buccal zone: improve lower-face hollowing and accordion lines
- Nasolabial zone: soften nasolabial folds
- Labiomental zone: improve marionette lines and downturned mouth corners
How do bone, fat, muscle, and skin changes combine to cause facial sagging?
Facial aging does not occur in a single layer. It affects bone, fat pads, muscles, the dermis and SMAS, and the epidermis simultaneously, with characteristic changes in each.
- Bone resorption : Reduced support for the facial contour accelerates sagging.
- Atrophy and descent of deep fat pads : The midface loses volume and becomes hollow.
- Changes in muscle function : Excessive tension accentuates wrinkles, while reduced strength contributes to sagging.
- Collagen loss in the SMAS and fibrous septa : Reduced tissue elasticity deepens sagging and wrinkles.
- Thinner skin, reduced elasticity, and dehydration : These typical features of aging skin increase fine lines and roughen texture.
Many aesthetic clinics begin by adding volume. Without improving elasticity and skin quality, however, volume alone can create an overfilled, unnatural appearance. The nasolabial and jowl fat pads are particularly prone to looking awkward when more volume is added.
In the forehead, aging brings sarcopenia to the frontalis, the principal elevator muscle. Muscle-fiber density and size decline, and resting tone weakens. Because the frontalis is the only muscle that elevates the brows, reduced strength can worsen eyelid ptosis and forehead lines.
When the frontalis contracts, the lower forehead skin moves cranially and the upper skin moves caudally. The point where these movements meet is called the line of convergence, or C-line. It lies at approximately 61% of forehead height and corresponds to the second horizontal forehead line from the top. The frontalis is the sole brow elevator, opposing the orbicularis oculi, depressor supercilii, corrugator supercilii, and procerus. Because it lies within soft tissue without a bony attachment, contraction draws both ends toward the center and moves the skin in opposite directions: the lower portion raises the brows, while the upper portion lowers the hairline.
How does treatment differ for the forehead, eye area, and midface?
Forehead
Loosening of the retinacula cutis connecting the frontalis to the skin reduces forehead elasticity. Weakening of supports such as the superior temporal septum and galea aponeurotica can also disrupt continuity between the lateral forehead and temple. The central brow may descend heavily, and lateral brow ptosis can develop. Long-term botulinum toxin use when the frontalis is already weak may make eyelid drooping more apparent.
Figure 1. Relationship of the line of convergence to upper and lower frontalis fibers, and injection points along the C-line. Source: Locking the Line of Convergence by Botulinum Toxin Type A for the Treatment of Dynamic Forehead Wrinkles, Yehia Farouk El Garem et al., Journal of Cosmetic Dermatology, October 2022, 22(12), DOI:10.1111/jocd.15468.
Addressing functional and structural forehead aging requires treatment across several layers. First, direct frontalis stimulation with a device using HIFES (High-Intensity Facial Electrical Stimulation) can help restore muscle function. This can improve resting tone and elevate the brows. By restoring the contraction pattern and the C-line's bidirectional skin movement, the aim is a more natural structural improvement rather than wrinkle smoothing alone.
Second, RF-based energy devices can help regenerate the retinacula cutis and extracellular matrix at the skin–muscle interface. Collagen remodeling and elastin production are used to restore skin elasticity.
Third, for lateral brow ptosis caused by weakened temporal support, a temporal thread lift or temple filler can reinforce support connected to the galea aponeurotica and superficial temporal septum.
Fourth, small, selective doses of botulinum toxin can treat superficial forehead lines. Treatment must take reduced muscle function and imbalance into account, keeping both the treated area and the dose to a minimum. In particular, it is better to inject the lateral forehead selectively while sparing the upper central forehead. If the skin itself has thinned, I recommend combining this with skin-booster injections to restore dermal density.
Forehead aging is a combined problem of reduced frontalis function, weakened extracellular connections, and loss of temporal support. Treatment planning therefore needs to address muscle, dermis, retaining ligaments, and the periosteal region together.
Periorbital Region
In the periorbital region, the orbicularis oculi is a thin circular muscle that maintains tension around the eye. With age, its tone declines and sarcopenic thinning develops, worsening under-eye festoons and protruding fat. The orbital retaining and orbicularis retaining ligaments anchor periorbital fat and skin; when they weaken, the tear trough and palpebromalar groove become more apparent. Loss of elastic fibers and hyaluronic acid in the extracellular matrix reduces overall skin tension. Clinically, the tear trough deepens, the small muscular roll beneath the lashes flattens, and the under-eye skin becomes thinner and more hollow.
Periorbital aging combines muscle atrophy, weakened ligaments, and loss of extracellular matrix. A treatment plan addressing muscle activation, ligament support, and skin reconstruction is needed to improve these changes and restore a balance between periorbital volume and natural expression.
When the orbicularis has lost function and tone, HIFES-based muscle stimulation can restore the resting tone of the muscles of expression. Stimulating the thin circular muscle of the lower eyelid can help maintain under-eye volume and limit fat protrusion.
A stable connection between under-eye skin and fat requires stronger retaining ligaments, particularly the ORL, and reconstruction of the extracellular matrix. Fractional RF or ultrasound can be used for this purpose. The proposed mechanism is collagen stimulation, elastic-fiber reorganization, and increased dermal density to restore under-eye tension. For hollowing and thin skin, skin-booster injections can restore dermal thickness and hyaluronic acid content within the matrix.
For deep tear troughs and palpebromalar grooves, precise placement of small amounts of low-G′ filler in a deep, supraperiosteal plane or just beneath the dermis can restore support beneath the hollow. Skilled technique is essential because of the region's venous and lymphatic drainage and sensitive anatomy. Prominent festoons may also require an approach that reduces excessive fat volume.
Midface
The midfacial skeleton comprises the maxilla and zygoma. Deep fat includes deep medial cheek fat (DMCF), suborbicularis oculi fat (SOOF), and the buccal fat pad. Superficial compartments include medial cheek, middle cheek, nasolabial, and lateral cheek fat. Supporting structures include the zygomatic and orbital retaining ligaments and the retinacula cutis, the fibers connecting skin and fat. Associated muscles include the orbicularis oculi; zygomaticus major and minor, which elevate the mouth corner; and the levator labii superioris (LLS) and levator labii superioris alaeque nasi (LLSAN), which elevate the upper lip. Relative overactivity of the LLSAN or LLS can accentuate nasolabial folds.
Figure 2. Eyelid anatomy referenced to the pupil, with structures located as if around a clock face. ORL, orbital retaining ligament; ZCL, zygomatic cutaneous ligament; SOOF, suborbicularis oculi fat. The off-white dotted line marks the festoon-forming area; the yellow dotted triangle marks the region of maxillary bone resorption; and the three solid yellow ovals indicate the orbital fat pads above the ORL. Source: https://plasticsurgerykey.com/contouring-procedures-of-the-face-handling-the-soof-the-nasojugal-fold-and-the-infraorbital-hollowness.
Midface aging begins with skeletal retrusion: posterior maxillary resorption reduces anterior support. Descent of SOOF and DMCF deepens the tear trough and nasolabial fold. Fragmentation of superficial fat leads to volume loss and redistribution, worsening midface hollowing, the midcheek groove, and nasolabial folds. Reduced muscle tone and contraction accelerate descent around the modiolus, the muscular convergence at the mouth corner. Loss of ligament elasticity is associated with malar mounds, festoons, and jowls. Common clinical concerns include nasolabial folds, tear troughs, midcheek grooves, cheek hollowing and loss of anterior cheek volume, and downturned mouth corners caused by modiolus descent.
For skeletal retrusion and loss of anterior midface volume, high-elasticity filler placed on the maxillary periosteal plane can restore forward support and rebuild central midface structure. Reinforcing the infraorbital rim, medial cheek point, and pyriform aperture can also indirectly improve tear troughs and nasolabial folds. Volume lost through descent of SOOF and DMCF can be restored with filler planned around the deep fat compartments. If the buccal fat pad has descended excessively, selected RF or HIFU treatment can encourage fat contraction and collagen remodeling.
Redistribution and fragmentation of superficial fat call for filler placement across multiple layers. A medium-G′ filler can shape volume in the intermediate layer, while soft filler or a skin booster in the superficial layer can restore smoothness and hydration. Needle or cannula access must be selected according to anatomical risk zones, with particular attention to the angular artery and infraorbital foramen.
When muscle function and tone are reduced, a muscle-stimulation device can reactivate the zygomaticus major and minor, LLS, and risorius and restore their resting tone. This structural approach addresses the direction of expression and mouth-corner elevation as well as volume.
For malar mounds and midcheek grooves caused by weakened retaining ligaments, thread lifting can restore skin anchoring. Planning the lifting vector along the zygomatic and orbital retaining ligament lines is particularly useful.
When the midfacial extracellular matrix is generally weakened, dermal stimulation with RF or fractional microneedling is essential. Encouraging collagen production and elastin restoration can recover skin tension and density.
Figure 3. Surface markings for midface analysis on the left hemiface: malar equator (ME), medial vertical reference (MVR), lateral vertical reference (LVR), lower malar partition (LMP), upper malar partition (UMP), and infraorbital rim margin. Source: Pertinent Anatomy and Analysis for Midface Volumizing Procedures, C. Surek et al., Plast Reconstr Surg. 2015 May;135(5):818e–829e. doi:10.1097/PRS.0000000000001226.
A single procedure has limits in the midface. Planning needs to integrate bone, fat, muscle, skin, and ligaments. An approach grounded in each patient's skeletal anatomy, pattern of fat redistribution, and muscle activity can restore midface volume while improving expression naturally.
(To be continued in the next issue)
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