2 Facial Fat Compartments

10.1055/b-0040-177244

2 Facial Fat Compartments

James M. Stuzin

Abstract

Facial fat differs from fat in other regions of the body as it is compartmentalized. Each facial fat compartment exhibits septal boundaries, a regional perforator blood supply, and a specific tendency toward deflation in aging.

Recognition of compartment anatomy is one of the keys to safe subcutaneous dissection of the cheek, as facial nerve branches are often superficially positioned at transition points between compartments. Recognition of compartment-specific deflation provides a guideline for volume restoration in facial rejuvenation.

Key Points

Subcutaneous facial fat is not homogeneous but rather partitioned into a series of compartments separated by specific fibrous septa.
Each facial fat compartment has its own vascular blood supply, thickness and fascial consistency.
Some fat compartments are thin and fibrous, while others typically contain a large volume of easily dissectible fat. The compartmentalization of facial fat explains the regional variation noted in the subcutaneous plane when dissecting from the preauricular area anteriorly.
The facial fat compartments also serve as a model for deflation, confirming the observation that facial deflation in aging is compartment-specific rather than occurring homogeneously throughout the cheek.
Facial fat compartments exist both superficial and deep to the SMAS (▶ Fig. 2.1a,b and ▶ Fig. 2.2 ).
- The superficial facial fat, which lies within the subcutaneous plane, is superficial to the SMAS, and it is this fat which can be manipulated in an SMAS facelift.
- Deep fat compartments, which are situated anteriorly along the orbit, maxilla, zygoma, and pyriform aperture, lie deep to the mimetic muscles and overly the periosteum of the orbit and midface. The deep fat of the cheek is contiguous with that of the lower lid. Deep malar fat along the anterior midface provides anterior cheek volume.
- Of note, both the superficial and deep fat compartments deflate over time, and this deflation is responsible for many of the morphologic changes seen in the aging face.

**Fig. 2.1 (a)** The superficial facial fat compartments are situated in the subcutaneous plane, partitioned by the terminal extensions of the retaining ligaments. The five superficial compartments of the cheek from lateral to medial are 1) lateral 2) middle 3) malar 4) jowl and 5) nasolabial. Each compartment has its own septal boundaries, a separate perforator blood supply and its own tendency to deflation in aging. **(b)** Cadaver dissection of the facial fat compartments of the cheek. The inked compartment shown is the middle compartment. The red arrow marks the transition between the middle and malar compartments, which are separated by a high density of zygomatic ligaments along the lateral zygoma. (*Reproduced from Rohrich, R. Pessa, J. The Fat Compartments of the Face: Anatomy and Clinical Implications for Cosmetic Surgery. Plast. Reconstr. Surg. 119: 2219, 2007*.)

**Fig. 2.2** The deep facial fat compartments are situated deep to the mimetic muscles and superficial to the periosteum of the midface. The deep fat of the lower lid is located just deep to the orbicularis oculi and is divided into medial and lateral components. The deep malar fat similarly is situated deep to the elevators of the upper lip and is separated into medial and lateral components. In youth, the deep periorbial fat blends with the deep malar fat to volumetrically support the lower lid and cheek. In aging, deflation of deep fat produces a loss of anterior cheek volume and an abrupt demarcation along the lid cheek junction, and it contributes to the formation of the infraorbital V-deformity.

2.1 Compartmentalization of the Superficial Fat Compartments

Superficial facial fat is separated into specific compartments by the terminal extension of the deeper retaining ligaments, which percolate through the cheek from deep to superficial to insert into the skin as retinacular cutis.
Rather than being diffuse in their penetration of the SMAS, the retaining ligaments penetrate the superficial fascia at specific locations and thereby form the fibrous septum which are formed between compartments.
These junctional boundaries also are the location where the vascular perforators to cheek skin penetrate from deep to superficial.
The surgical significance of this is that when encountering numerous perforators while performing subcutaneous dissection, anatomically the dissection is transiting from one superficial fat compartment to another.
While there are many superficial fat compartments, the five compartments that the surgeon encounters in a facelift include the lateral compartment, middle compartment, superficial malar compartment, nasolabial fold compartment, and jowl compartment.
As subcutaneous dissection proceeds from laterally in the preauricular region medially, if the dissection is performed under direct visualization, it is possible for the physician to recognize both what compartment is being dissected as well as when the transition between compartments occurs (▶ Fig. 2.3 and Video 2.1).

**Fig. 2.3** Cadaver dissection at the junction between the middle and malar compartments along the lateral zygmoma. When transiting compartments, retaining ligaments are encountered as well as vascular perforators. The scissors in this photograph are situated where the zygomatic ligaments inset into the skin (separating the upper middle compartment from the malar compartment). The density of ligaments in this region can obscure proper plane identification, and it is safer to dissect superficially along the transition point between the middle and malar compartments, as the zygomtic motor branches lie directly sub-SMAS in this location. Notice the numerous vascular perforators present at this location, typical of vascular perforators located along transition points between compartments. Once the subcutaneous dissection proceeds anterior to the middle compartment, the mobile region of the cheek is encountered.

2.1.1 Lateral Compartment

The lateral compartment is located in the preauricular region and tends to be narrow, thin, following the superficial temporal artery cephalically within the temporal region.
Typically, the lateral compartment is only 3 to 5 cm in width and consists of dense, vascular, and fibrous fat.
This compartment is directly situated overlying the parotid gland, and as the dissection proceeds anterior to the parotid, the middle compartment is encountered, and the dissection becomes less fibrous (▶ Fig. 2.4 ).