Facial Augmentation

This study documents the anatomy of the deep attach- ments of the superficial fasciae within the temporal and periorbital regions. A highly organized and consistent three-dimensional connective tissue framework supports the overlying skin and soft tissues in these areas.

The regional nerves and vessels display constant and predictable relationships with both the fascial planes and their ligamentous attachments. Knowledge of these rela- tionships allows the surgeon to use the tissue planes and soft-tissue ligaments as intraoperative landmarks for the vital neurovascular structures. This results in improved efficiency and safety for aesthetic procedures in these regions. (Plast. Reconstr. Surg. 105: 1475, 2000.)

The patterns of arrangement of the layers of superficial fascia in the cheek,1±9 forehead,10 ±13 scalp,14 and temple15,16 have been well de- scribed. This superficial fascia in the temple, forehead, and periorbital regions meets the definition of a SMAS layer as described in the midface.1 The superficial fascia thus extends like a mask throughout the whole of the face. The descriptions of these layers have found wide application to aesthetic surgery.17±19

The areolar tissue plane beneath the fibrous layer of the superficial fascia of the temple has been given numerous names.14,20 A subsuperfi- cial fascial plane is located deep to the galea in the upper face, the SMAS in the midface, and the platysma in the neck. The ease of dissec- tion along this plane in the scalp and forehead results from the relative paucity of connective tissue attachments between the galea and the underlying deep fascia or pericranium.

The superficial fascial layer is retained by a

complex system of deep attachments that arise from the underlying deep fascia/periosteum. The subSMAS plane that contains these attach- ments is therefore not always a simple cleavage plane. This explains why surgical dissection is considerably more complicated in the midfa- cial, temporal, and periorbital regions than in the scalp.

In the cheek, these deep attachments have been defined as the zygomatic, masseteric, and mandibular-cutaneous ligaments.21,22 These lig- aments provide a lateral line of fixation for the mobile tissues of the medial cheek. Release of these retaining ligaments is fundamental to the extended SMAS technique of ªdeep-planeº sur-

gery.18,19,23,24

The ligaments act as markers to the position of the facial nerve branches in the cheek.19 The zygomatic and buccal branches emerge from the masseteric fascia and cross the subSMAS plane to the underside of the SMAS. This pas- sage occurs just medial to the cheek ligaments. The ligaments therefore retain the overlying SMAS and protect the facial nerve branches as they cross this glide plane.

In facial rejuvenation surgery, the deep- plane method achieves a tightening of the me- dial cheek soft tissues. After the retaining liga- ments are released, the superficial fascia can be drawn posteriorly. The facial nerve branches are simultaneously identified and preserved during surgical ligament release.

Previous authors have provided a great deal

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of information on the deep attachments in the cheek.18,21 Recently, studies have begun to in- vestigate deep attachments found in the tem- poral12,25 and periorbital regions.26,27 These ar- eas are therefore the focus of this article.

The origin and pattern of migration of the embryonic facial muscles that occur in the mid- face also occur in the upper face.28,29 Accord- ingly, it could be expected that the upper face would display similar tissue and neurovascular arrangements.

The relationships of the facial nerve16,30 ±32 and sensory nerves33 to the fascial planes in the upper face have received much attention. Al- though helpful in identifying the layer of pas- sage of the facial nerve branches, these studies do not define their exact course. Currently, surface anatomy landmarks are widely used in locating the facial nerve.34,35 However, surface anatomy is not sufficiently precise for intraop- erative dissection when facial nerve branches are involved.

This investigation commenced with the hy- pothesis that, as in the cheek, the internal soft- tissue ligaments of the temporal and perior- bital regions display a constant anatomy with predictable relationships to the temporal branches of the facial nerve. The aim of the study was therefore to define this not previ- ously described anatomy. Although the data reported in this article pertain only to the tem- poral and periorbital regions, they are derived from a comprehensive study investigating the superficial tissues of the whole face and neck.

MATERIALS AND METHODS

This study involved dissection of 22 facial halves. All were performed on fresh cadavers of normal body mass index with ages ranging from 60 to 78 years. Preserved (formalinized) cadavers were excluded because they distorted the delicate connective tissue and facial nerve anatomy. Of the 22 dissections, 10 were per- formed following intraarterial vascular injec- tion with a lead oxide mixture36,37 and 12 were performed in fresh specimens without arterial injection. These data were combined with the anatomic recordings from several hundred in- traoperative dissections including open coro- nal brow and temporal lifts and endoscopic temple lifts.

Dissection was performed under 33 loupe magnification according to a standardized technique that commenced with a coronal in- cision, entered the subgalea plane, and then

PLASTIC AND RECONSTRUCTIVE SURGERY, April 2000

proceeded in a caudal direction over the fore- head and the temporal, periorbital, and facial regions. Loose areolar tissue was gently dis- sected away, preserving the dense connective tissue attachments between the deep and su- perficial tissues. The precise locations of these attachments were recorded on a standardized worksheet with reference to specific fixed bony landmarks. The relationships of the major neu- rovascular structures to both the connective tissue attachments and the fixed skeletal land- marks were documented carefully with appro- priate measurements.

The cadavers that underwent initial vascular injection were dissected with an identical tech- nique and provided additional information on the relationships between the arterial supply and both the connective tissue layers and their attachments. The uninjected specimens pro- vided detailed information on the cutaneous sensory nerves and fine motor branches of the facial nerve.

RESULTS

Arrangement of the Tissue Layers

The tissues are arranged into two basic layers that may be summarized under the headings of the superficial and the deep fasciae. A contin- uous layer of superficial fascia comprises the galea occipitofrontalis, the superficial tempo- ral fascia, the SMAS of the zygomatic and cheek regions, and the platysma. This SMAS system receives the insertion of those facial muscles arising directly from bone such as the zygomaticus major and minor; it also envelops the flat muscles such as orbicularis oculi that have important attachments around their pe- rimeter to the SMAS layers.

An easily developed surgical plane exists be- tween these deep and superficial tissue planes. This subsuperficial fascial plane is a potential space that mainly contains loose areolar or fibro-fatty tissue. In predictable locations, dis- section through this plane is limited by the fibrous and muscular attachments that retain the superficial tissues.

Classification of Ligament Morphology

The fibrous attachments retaining the SMAS layer and skin to the deep tissues may be col- lectively referred to as the ligamentous attach- ments of the superficial tissues. The individual ligaments have predictable and constant loca-

tions; however, they vary in the density of their fibrous tissue.

Clear description of the ligamentous anat- omy in the superficial tissues of the head and neck has required the introduction of a num- ber of new terms. The ligaments have been classified according to three morphological forms: true ligaments, septa, and adhesions (Fig. 1).

True ligament. A true ligament is similar to a skeletal ligament in that it is a discrete cylin-

drical arrangement of fibrous tissue that is sur- rounded by fatty tissue. True ligaments were found in the medial midface and lower face and provided the greatest latitude of movement of all the attachments (Fig. 1). True ligaments arise from either the deep fascia or the perios- teum. They then cross the subSMAS plane to the undersurface of the SMAS, where they di- vide into numerous branches in a tree-like fash- ion. These branches then distribute the attach- ment of the ligament to the dermis through a

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subcutaneous fascial system, the retinacula cu- tis.9,14,38 Examples include the zygomatic and masseteric ligaments (Fig. 1).

Septum. A septum is a fibrous wall passing between the deep fascia and the undersurface of the SMAS (Fig. 1). This arrangement permits mobility only in a plane perpendicular to the deep line of attachment of the septum. Most of the septa defined within the head and neck are located in the temporal and periorbital regions. Examples include the inferior temporal sep- tum, the superior temporal septum, and the periorbital septum (Fig. 1).

Adhesion. The third form is a low-density area of fibrous or fibro-fatty adhesion between the deep fascia/pericranium and the superfi- cial fascia (Fig. 1). Basically a two-dimensional structure, an adhesion restricts mobility in all directions and to the greatest degree of the three forms. It is important to note that septa

PLASTIC AND RECONSTRUCTIVE SURGERY, April 2000

and adhesions retain the SMAS plane only, and considerable mobility may still occur at more superficial layers. Aside from the preauricular and parotid regions, adhesions were found only in the forehead and temporal regions. Exam- ples include the temporal (Fig. 1) and the su- praorbital ligamentous adhesions.

The deep attachments of the superficial fas- cia in the temporal and periorbital regions comprised only septa and adhesions. No true ligaments were seen in these regions.

The Temporal Ligamentous Adhesion

The temporal ligamentous adhesion (tem- poral ligament) supports the region immedi- ately superior to the eyebrow at the junction of its middle and lateral thirds (Figs. 2 and 3). Located at the intersection of the temporal, frontal, and periorbital regions, it is a well-