The facial skin and subcutaneous tissue (referred to as the soft tissue ‘flap’) comprise a dense, superficial formation of connective tissue that makes up the dermis and epidermis, a honeycomb web-like subdermal structure of connective tissue embedded in fat lobules, and muscle, which traverses the soft tissue flap (Fig. 25.1). Anatomical studies show that the immediate subdermal layer contains a large connective tissue network made up of small fat lobules with many septa, whereas the deeper subdermal layer features large fat lobules with only a few septa. Dynamic musculature presents in sometimes overlapping, multiple layers, and may even form entire complexes – as in the brow area where the frontalis, corrugator, and orbicularis muscles merge into one complex with the ability to move medially, proximally, and distally (F. Anderhuber, personal communication).

Figure 25.1 Facial skin and subcutaneous tissue.

The analysis of the anatomical composition of the connective tissue is of greatest interest in volume augmentation. The soft tissue flap is attached to the underlying bony structure via connective tissue bands called retinacula or real retaining ligaments (Fig. 25.2), which show no or very limited elasticity. So-called false retaining ligaments – the most important of which include the nasolabial fold, the zygomatic ligament, and the maxillar–buccal ligament (Fig. 25.3) – add to the character of the flap surface. Although false retaining ligaments have no bony attachment, they act in a fence-like manner, compressing dynamic muscular activity and influencing the appearance, shape, and correction of the skin surface.

Figure 25.2 Real retaining ligaments.

Figure 25.3 False retaining ligaments.

A brief description of the soft tissue anatomy of the human face is not complete without a discussion of the fat compartments, which are located around and below the eye, in the cheek, and in the perioral region (Fig. 25.4). The suborbicularis oculi fat (SOOF) and retro-orbicularis oculi fat (ROOF) pads are the dominant features of the periorbital region. As the most proximal entity in the mid-facial region with the least coverage of musculature structures, the SOOF pad plays a key role in the process of facial aging and has a direct impact on the clinical presence of the medial and lateral infraorbital hollow. Another important, shape relevant structure in the submalar area is induced by an indented groove from the medial orbital hollow to the lateral lower midface caused by the zygomatic ligament.

Figure 25.4 Fat compartments of the face. SOOF, suborbicularis oculi fat.

Biological characteristics of filler materials

Autologous fat or other biodegradable materials, such as hyaluronic acid (HA), calcium hydroxylapatite (CaHA), or poly-l-lactic acid (PLLA), are the most frequently used agents in volume replacement soft tissue augmentation today. All agents differ with respect to interaction with the recipient site and therapeutic effect in the tissue. In this respect, the main characteristics of interest include overall duration of effect, neocollagenesis, and water retention.

Autologous fat

Although autologous fat is almost always harvested from a tumescent donor site, the hydrated fat tissue will dehydrate after injection at the recipient site. Owing to the microanatomical structure of fat tissue, injections must be performed using 18-gauge cannulas, or larger. After transplant, neofibrogenesis and neocollagenesis occur; no significant additional water retention can be observed.

Hyaluronic acid

Today, multiple formulations of HA are available for different purposes in soft tissue augmentation. For volume replacement, preparations with concentrations of 20–24 mg/mL are produced. Aside from the primary effect of volume contribution through implantation of the physical material, HA leads to marked water retention; this additional accumulation of fluid due to the binding capacity of the filler leads to a biological change in the atrophied subcutaneous tissues, wherein the rehydration at the site of injection is followed by a secondary redistribution of subcutaneous fluids. Theoretically, shrunken and atrophied fat lobules – from severely diminished blood supply during the aging process – will reinflate (F. Anderhuber, personal communication). In 2007, Wang et al found that degradation depends on the stabilization of HA; highly stabilized products can produce a secondary neofibrogenesis.

Calcium hydroxylapatite

CaHA is a long-lasting, biodegradable filler that can also accumulate water, but only to about 10% of the amount that HA is capable. The persistence of its augmentative effect is due to the mass of filler material injected, which, as it degrades only slowly, affords long-term correction, also due to neofibrogenesis.

Poly-L-lactic acid

PLLA induces neofibrogenesis and leads to a reinforcement of connective tissue fibers that have undergone the process of elastosis. The interaction between tissue and filler material spurs the production of new collagen fibers by fibroblasts without any relevant fluid retention.

New concepts in injection techniques

Soft tissue volume correction of the mature face can be compared to the remodeling of an older home: valuable repair and renovation cannot be achieved by simply fixing the roof. Similarly, correction of soft tissue volume deficiencies needs to address the underlying structural support at all levels and compartments, as well as the surface defects, respecting anatomical identities and their influence on dynamic three- and four-dimensional aspects. Vertical injections, such as the tower and the vertical supraperiosteal depot (VSD) techniques, offer the best control for an exact and predictable soft tissue augmentation approach.

The tower technique

The tower technique – to be used with HA fillers alone – is a novel method of soft tissue augmentation that reintroduces structural support that has been lost through lipodystrophy and bone resorption. Horizontal layers of tissue (fascia, connective tissue, muscle, fat, and dermis) are attached to each other with a limited lateral flexibility. The tower technique deposits small amounts of HA in the tissue planes, like multiple washers between each layer (Fig. 25.5). By injecting filler vertically (90° to the base of the injection site) and gradually tapering product deposition as the needle is withdrawn, the clinician is able to build towers or columns of HA that serve as scaffolds for the overlying soft tissue structures, thus creating a deep base of support that extends through the entire subcutis.

Figure 25.5 The tower technique.

The clinician gathers up the area to be injected between the thumb and second finger of the non-dominant hand. A 24–27-gauge, half-inch (1.25 cm) needle is inserted perpendicular to the skin at the desired depth based on the anatomical location (Table 25.1). After checking to ensure that the needle has not been placed in a vessel, the plunger is depressed and HA slowly injected as the needle is withdrawn vertically, using ever-decreasing amounts of product to create a pyramid-like support with a larger volume of HA deposited at the base and a gradual tapering of product deposition (Fig. 25.5A). The towers are usually placed in a line along the fold or groove, with each injection approximately 0.5–1 cm apart (Fig. 25.5B).

Table 25.1 Injection depth based on anatomical location

Treatment area	Depth
Lateral brow	Periosteum
Infraorbital hollow	Periosteum
Cheek	Deep subcutis
Zygomatic ligament	Deep subcutis
Nasolabial folds	Deep subcutis
Inferior marionnette lines	Periosteum
Superior marionnette lines	Deep subcutis
Pre-jowl sulcus	Periosteum
Chin	Periosteum

The columns are self-supporting, floating in the soft tissue plane without any additional support required – although the technique is best used in areas with underlying bony landmarks, a thick subcutis, or a thicker overlying dermis. As such, the tower technique is recommended to fill nasolabial folds and marionette lines, revolumize the chin and pre-jowl sulcus, and add volume to the lateral brow and cheek. Thin-skinned areas, such as the periorbital area, are unlikely to tolerate a more superficial placement of HA; it is best to avoid placement in the superficial dermis to avoid the Tyndall effect. Other areas that may be less amenable include the glabella, nasal dorsum, and the lips – although it is possible to use submuscular injections into the white part of the upper or lower lip for more controlled augmentation.

Pearl 1

Vertical injections in the real mandibular retaining ligaments will elongate the ligaments, thus creating a continuous jawline.

Vertical supraperiosteal depot technique

In comparison to the tower technique, the VSD technique features vertical injections directly on the bone, or more precisely – on the periosteum (Fig. 25.6). As in the tower technique, the clinician grasps the area to be injected between thumb and forefinger of the non-dominant hand for maximum penetration and pierces the skin at the thinnest entry point with a 24–27-gauge half-inch needle, using a 90° angle. After repositioning the cannula at the level of the bone and advancing slowly below the soft tissues, the augmenting agent can be deposited in aliquots of 0.1–0.3 mL at each injection point, depending on the depth of the defect, with a distance of up to 5 mm between injection sites.

Figure 25.6 The vertical supraperiosteal depot technique.

Because of the bony support, only a minimal amount of filler is needed in order to have a pronounced correction on the surface of the skin – as can be observed in the area of the orbital hollow over the medial part of the orbital rim (Fig. 25.7) or the zygomatic bone. Using small amounts of filling agent reduces the incidence of overcorrection and risk of associated side effects. Other areas that may benefit from the VSD technique include the upper orbital rim just below the brow, the dorsal area of the nose, the mandibular bone, and the entire forehead.

Figure 25.7 Infraorbital hollow before and after treatment with hyaluronic acid and the vertical supraperiosteal depot technique.

Injection tips and post-treatment recommendations

In areas without sufficient underlying firm anatomy, as in the cheek and perioral region, both techniques can be used with the additional intraoral placement of the contralateral indicator finger for an ‘in-oral’ support, as well as for control and correct placement of the filler material. In order to achieve the desired results, HA fillers should be placed below the dynamic musculature, particularly in the perioral region for the volumetric correction of the nasolabial fold, marionette lines, and the upper and lower lip. Softer HA gels are recommended for more superficial use, while the more robust or cohesive products can be chosen for deeper volumizing implantations.

Careful and cautious manual massage of the treated sites after augmentation will help distribute the filler material evenly and allow the clinician to gauge the extent of correction and check for untreated areas. After treatment, the patient should be advised to ice the injected areas intermittently throughout the night. However, the minimal injection points and limited subcutaneous movement of the needle keep the level of discomfort low and reduce the risk of bruising or other damage caused by tissue trauma.

Three-dimensional augmentation using vertical injection techniques and biodegradable or semibiodegradable agents is a long-term commitment with multiple treatment sessions required to optimize and sustain the cosmetic result. In the first year, two to four treatments may be necessary; after complete restoration and patient satisfaction have been achieved, one follow-up treatment per year is usually all that is needed to maintain the result, which will eventually become permanent. Combination therapy with botulinum toxin markedly supports the effect of augmentation procedures.

The most common injection-related side effects include bruising and swelling. Severe bruising can be avoided by persistent compression. More severe bleeding can lead to an extensive hematoma lasting for up to 2 months, which can be troublesome for the patient. Post-injection swelling is common, particularly after treatment with HA fillers. A dramatically swollen appearance is often alarming. Using lower total volumes and advising patients to sleep with the head elevated will do much to alleviate the incidence of edema.

Pearl 2

Post-injection hematomas or deep bruising lasting 1–2 weeks can be avoided or diminished by focused manual compression for more than 10 minutes.

Pearl 3

The use of blunt cannulas can reduce or even eliminate bruising and may be considered in patients with immediate appointments or other work-related functions following treatment.

Pearl 4

High volumes up to 5 mL of a 20 mg/mL hyaluronic acid filler per side of a human face should not be exceeded.

Serious complications in facial augmentation are extremely rare when the correct filler materials are used. Still, the theoretical possibility of an intravascular injection exists and happens more often than one would like. If HA has been used as the augmenting agent, immediate injection of hyaluronidase directly into the vessel or in the area of the thrombotic situation is advised. Similarly, biofilm-like inflammatory reactions to HA fillers may lead to a firm swelling and tissue reaction, as well as a moderate rise in tissue temperature. Treatment includes focal injection of hyaluronidase in the area of swelling, and the addition of anti-inflammatory and antibiotic therapy administered accordingly.

Case Study 1

A 58-year-old woman requests aesthetic improvement around and below her eyes to alleviate what she feels is a ‘tired’ look. A shy woman, she has contemplated facial rejuvenation for a long time but has been too embarrassed to ask. She refuses a major surgical procedure such as a facelift, but is interested in something less invasive in order to improve her outward appearance. Examination shows a marked blepharochalasis of the upper lids and severe loss of volume in the lower eyelid and mid-face areas. Furthermore, the patient exhibits clearly visible horizontal forehead lines and glabellar fold, lipohypertrophy of the lower eyelids, a deep and pronounced nasolabial fold, and severe marionette lines. Multiple, hypertrophic nevi on both cheeks are evident.

Treatment begins with 4 mL hyaluronic acid (HA) (Juvéderm^® Voluma) injected into each side of the mid-face region using the vertical supraperiosteal depot injection technique, with another 2 mL injected using the tower technique into the nasolabial fold and marionette lines. Superficial rhytides in those areas are treated with a lighter HA product (Juvéderm^® Ultra II). A total of 50 U botulinum toxin type A (BoNT-A; BOTOX Cosmetic^®) is injected into the glabella, both eyebrows, the lateral canthal rhytides, mid-forehead, and the chin. Approximately 1 month later, the patient returns for an additional 1 mL of HA (Juvéderm^® Voluma) into each side of the residual existing zygomatic ligaments using the tower technique. After another month, the treating clinician performs a bilateral upper eyelid blepharoplasty and removal of four nevi in both cheeks and right upper lip, under local anesthesia. The stitches are removed after 5 days. The following month, the patient receives another touch-up of 2 mL HA (Juvéderm^® Voluma) in the cheeks, zygomatic ligaments, nasolabial folds, and marionette lines, along with treatment of superficial wrinkles using 1 mL of lower viscosity HA (Juvéderm^® Ultra II). Botulinum toxin follows, with another 50 U in the glabella, eyebrows, lateral canthal rhytides, mid-forehead, and chin. Two injections of 0.3 mL hyaluronidase – spaced 1 month apart – are required in the very superficial aspect of each tear trough and zygomatic ligament. The patient receives a total of five treatment sessions in 5 months, with follow-up 1 year later (Fig. 25.8).

Figure 25.8 Patient before (A) and at 1-year follow-up (B) after a total of five treatments between May and October 2010.

Case Study 2

A 41-year-old female who considers herself ‘an early ager’ wants to improve her appearance and receives a total of four injectable treatments: three treatments of 50 U per session of BoNT-A (Xeomin^®) in the area of the glabella, brows, lateral canthal rhytides, and the chin; and soft tissue augmentation of the cheek with 4 mL of high-viscosity hyaluronic acid (HA) (Belotero^® Intense; vertical supraperiosteal depot technique), plus an additional 8 mL of lower viscosity HA (Belotero^® Basic) to fill the nasolabial folds and marionette lines using the tower technique. To complete her rejuvenation, the patient undergoes an upper blepharoplasty under local anesthetic (Fig. 25.9).

Figure 25.9 Woman before (A) and after (B) treatment with botulinum toxin (glabella, brows, canthal rhytides, chin), hyaluronic acid augmentation (cheek, nasolabial folds, marionette lines), and upper lid blepharoplasty.

Case Study 3

A 62-year-old male has the impression that his outward appearance looks too ‘hard’ and does not reflect his romantic emotionality. He requests a softer, more attractive look (Fig. 25.10). He receives a total of five treatment sessions performed at intervals of about 2 months. Invasive procedures include surgeries (an upper blepharoplasty, a subcision of the submental fold, and multiple nevi excisions), and ablative carbon dioxide laser resurfacing of his lower eyelids (Fraxel^® re : pair). The tower and vertical supraperiosteal depot techniques are used to augment his face with different formulations of hyaluronic acid (Restylane^®, Perlane^®, and SubQ^®) to a total of 14 mL in the cheeks, nasolabial folds, lower eyelid margins, and marionette lines. In addition BoNT-A (Xeomin^®) is administered three times, 50 U per session, in the glabella, forehead, brows, lateral canthal rhytides, and chin.