For most of cosmetic medicine's history, facial fat was treated as a single layer that thinned uniformly with age. The clinical reality, established by anatomical work from Rohrich and Pessa in the mid-2000s and corroborated by subsequent imaging studies, is that facial fat is organised into discrete compartments separated by fibrous septa, and that those compartments change in different directions at different rates. The composite pattern is what produces the characteristic appearance of the ageing face.
Understanding compartmental anatomy changes how we plan treatment. The aim is no longer to fill where a line has formed. It is to restore the specific compartments that have changed, in modest volumes, in ways that respect the rest of the architecture.
Deep versus superficial fat
Facial fat sits in two broad strata. Deep fat lies beneath the SMAS, close to the underlying skeleton, and provides structural support for the overlying tissue. Superficial fat lies above the SMAS and contributes to surface contour. The two behave differently with age.
Deep fat: the cushion that goes first
Several deep fat compartments, including the deep medial cheek fat and the periorbital deep fat, tend to atrophy with age. Loss of these hidden cushions removes structural support from the midface, deepens the nasolabial fold, and contributes to a tired or hollow appearance long before any significant change in superficial fat or skin. Because deep fat is not visible on the surface, its loss is often misread as a skin issue or as a need for surface treatment.
Superficial fat: redistribution, not uniform loss
Superficial fat does not change uniformly. In some compartments, particularly along the lower face and jawline, it tends to hypertrophy, contributing to a heavier jawline silhouette and the formation of jowls. In others, particularly in the upper face and temples, it tends to atrophy, contributing to hollowing and a tired upper face. The same person can therefore appear to be losing volume in one zone and gaining it in another, both at once.
The compartments most commonly involved
- · Deep medial cheek fat: atrophies, removing midfacial support.
- · Nasolabial fat compartment: relatively preserved, becomes visually prominent as adjacent compartments thin.
- · Suborbicularis oculi fat (SOOF): redistributes around the orbit, contributing to under-eye hollows and lower eyelid changes.
- · Buccal fat: variable, with some atrophy contributing to a hollow lower cheek in selected patients.
- · Jowl fat compartment: tends to hypertrophy or shift inferiorly, contributing to jowling.
- · Submental fat: can accumulate, contributing to the appearance of a less-defined jawline.
- · Temporal fat: atrophies, contributing to hollow temples and visible vascular structures.
The ageing face is rarely losing fat everywhere. It is moving fat from where you want it to where you do not.
Why this matters clinically
The compartmental model has reshaped cosmetic practice over the last 15 years. The old approach was to place volume replacement treatments along the line that bothered the patient. The current approach, where treatment is indicated at all, is to identify the compartments that have changed and to restore them in modest, anatomically-guided volumes, using the smallest amount of product that achieves the goal. Done well, this approach can produce a more rested appearance without altering the patient's underlying facial proportions. Done poorly, it produces the over-filled, distorted appearance that the cultural conversation has rightly become more critical of.
What treatment can and cannot do
Modest restoration of lost deep compartments can re-support the overlying tissue and improve the appearance of the midface and periorbital region in carefully selected patients. Conservative work along the jawline and chin can improve definition in selected patients. Where superficial fat has hypertrophied or shifted, particularly along the jowl, non-surgical options are more limited and adding further volume often worsens the result. The honest answer in those cases is sometimes referral to a specialist plastic or facial surgeon for assessment.
Behavioural inputs
Significant weight fluctuation, particularly repeated cycles of loss and regain, can accelerate the appearance of compartmental change by stretching and emptying soft tissue repeatedly. Sustained weight stability is generally kinder to the long-term appearance of the face than aggressive cycling. Smoking, sun exposure and chronically poor sleep amplify the visible effect of compartmental change by also degrading the overlying skin.
What to look for at consultation
A careful assessment maps which compartments have changed, in which direction, before recommending any treatment. A practitioner who can describe the compartmental anatomy of a face in plain language is one who is more likely to deliver a result that ages well. A consultation that jumps straight to filling a fold without naming the underlying compartments is rarely the deeper conversation the patient deserves.
All cosmetic procedures carry risks. Outcomes vary between individuals. A consultation with a registered medical practitioner is required prior to any treatment. This article is general information only and is not medical advice.