Histotopographic Study of the Fibroadipose Connective Cheek System

Abstract

The purpose of this study was to investigate the morphology of the superficial musculoaponeurotic system (SMAS). Eight embalmed cadavers were analyzed: one side of the face was macroscopically dissected; on the other side, full-thickness samples of the parotid, zygomatic, nasolabial fold and buccal regions were taken. In all specimens, a laminar connective tissue layer (SMAS) bounding two different fibroadipose connective layers was identified. The superficial fibroadipose layer presented vertically oriented fibrous septa, connecting the dermis with the superficial aspect of the SMAS. In the deep fibroadipose connective layer, the fibrous septa were obliquely oriented, connecting the deep aspect of the SMAS to the parotid-masseteric fascia. This basic arrangement shows progressive thinning of the SMAS from the preauricular district to the nasolabial fold (p < 0.05). In the parotid region, the mean thicknesses of the superficial and deep fibroadipose connective tissues were 1.63 and 0.8 mm, respectively, whereas in the region of the nasolabial fold the superficial layer is not recognizable and the mean thickness of the deep fibroadipose connective layer was 2.9 mm. The connective subcutaneous tissue of the face forms a three-dimensional network connecting the SMAS to the dermis and deep muscles. These connective laminae connect adipose lobules of various sizes within the superficial and deep fibroadipose tissues, creating a three-dimensional network which modulates transmission of muscle contractions to the skin. Changes in the quantitative and qualitative characteristics of the fibroadipose connective system, reducing its viscoelastic properties, may contribute to ptosis of facial soft tissues during aging.

Melolabial Flaps for Nasal Reconstruction

“…In this region, studies have shown the SMAS to be thick and fibrous. 1 As the SMAS continues medially toward the melolabial fold, its fibrous connective tissue becomes progressively thinner because it envelops the mimetic muscles, including the zygomaticus major, zygomaticus minor, orbicularis oris, levator labii superioris, depressor labii inferioris, levator anguli oris, and depressor anguli oris. All these muscles surround the melolabial fold and send out vertically oriented fibrous septa to the dermal layer of the skin.…”

“…1). 1 While moving from the lateral cheek to the melolabial crease, the superficial adipose layer and SMAS thin, whereas the deep adipose layer thickens. Additionally, the SMAS envelops the mimetic muscle of the medial face.…”

The Infrapatellar Adipose Body: A Histotopographic Study

“…The subcutaneous tissue is structured in layers that correspond, from superficial to deep planes, to the epidermis, corium, superficial fibro-adipose connective layer, a laminar layer of connective tissue, a deep fibro-adipose connective layer and deep (muscular) fascia. This spatial arrangement shows structural differences in different anatomical sites [Macchi et al, 2010[Macchi et al, , 2014a, but there is also an individual variability of representation of the adipose lobules and septa [Sbarbati et al, 2010]. It is not known if structural differences exist between the IFP and other subcutaneous white adipose tissue depots.…”

The Clinical Importance of the Fat Compartments in Midfacial Aging

“…They called the soft tissue above the levator labii superioris and the zygomaticus major muscles the “medial” and the “lateral” cheek mass, respectively. In Macchi et al’s 20,21 cadaveric studies of facial anatomy, the “cheek” mass was vaguely defined as the soft tissue medial to the parotid and lateral to the nasolabial crease. Raskin and Latrenta 22 used arbitrary markings based on the aesthetic subunit principle of Gonzales-Ulloa et al 23 to divide the midfacial fat into the “anterior upper cheek,” “middle cheek,” and “posterolateral cheek” compartments.…”

“…The continuous compression of the deep fat pads against bone and their relatively inert role as space-filling interfaces over which the somatic muscles slide during mastication may explain their tendency to selectively atrophy over time. 21,29 On the other hand, the superficial fat pads’ proximity to the dynamic muscles of facial expression may render it more metabolically active, thus requiring a more extensive and vascularized fascial network compared to the deep fat compartments as shown in histologic studies. 16,22,24,28–30 Dedicated histologic studies are needed to further characterize the architectural networks of the deep and superficial fat layers.…”