Introduction and History
Injectable fillers provide a quick and predictable method of replacing lost facial volume, and they yield high patient satisfaction ( Fig. 19.1 ). Fillers are generally classified as either volumizers or stimulators based upon the mechanism of action. Volumizers are relatively inert substances that add bulk or volume, e.g. silicone, collagen, and non-animal, stabilized hyaluronic acid (NASHA). Stimulators have a biologic activity that creates additional volume through either a foreign body reaction (e.g. poly-L-lactic acid, dextran) or collagen stimulation (e.g. polymethyl methacrylate, calcium hydroxylapatite).
Fillers vary considerably in the duration of effect. Permanent fillers seem to be associated with higher rates of late-onset infection, granuloma, and induration. Furthermore, a permanent filler may yield unnatural results over time as it stays stationary while the face changes with aging.
Cosmoderm and Cosmoplast are composed of human collagen derived from a cell line from a newborn’s foreskin. Unlike the bovine collagen products, Cosmoderm and Cosmoplast do not require allergy testing. They contain lidocaine to reduce discomfort during injection, so rhytides require slight overfilling. Evolence® (OrthoNeutrogena, Morris Plains, NJ) is porcine collagen, which was recently approved by the FDA.
Non-animal source hyaluronic acid
Currently, our filler class of choice is non-animal, stabilized hyaluronic acid (NASHA) which is a clear viscous gel ( Fig. 19.2 ). NASHA fillers provide 6–12 months of tissue fill, are longer lasting than collagen, have a favorable side effect profile, do not risk disease transmission from an animal or human source, and avoid the theoretical risks of long-lasting solid particles. One of the most beneficial characteristics of NASHA fillers is that they can be immediately degraded by the injection of hyaluronidase. In December, 2003, Restylane® became the first FDA-approved NASHA product. It is produced from streptococci by bacterial fermentation and undergoes cross-linking to increase its resistance to enzymatic degradation. The FDA approved Restylane® (Medicis, Scottsdale, AZ) in December, 2003, for use in mid to deep dermal implantation for the correction of rhytides, but it has been available in Europe since 1996. Restylane® is distributed in 1.0cc and 0.4cc syringes, and does not contain any local anesthetic. Although this necessitates topical and/or local anesthesia, it also eliminates the need for overcorrection. One milliliter of Restylane® contains 100000 gel particles. In May, 2007, the FDA approved Perlane® (Medicis, Scottsdale, AZ). Perlane® has (10000 particles/mL) and is used to correct deeper folds. Perlane® is dispensed in a 1.0cc syringe. Juvéderm ™ Ultra and Juvéderm ™ Ultra Plus (Allergan, Irvine, CA) are NASHA fillers that were approved by the FDA in June, 2006. They are both dispensed in 0.8cc syringes. These NASHA products are in a pure gel rather than particle-suspension formulation. Juvéderm ™ Ultra is used for medium-depth wrinkles, and Juvéderm ™ Ultra Plus is used for deep wrinkles and folds ( Table 19.1 ).
|Product||Syringe||Common injection depth|
|Restylane®||0.4, 1.0||Mid dermis|
|Perlane®||1.0||Deep dermis, subcutaneous|
|Juvéderm™ Ultra||0.8||Mid dermis|
|Juvéderm™ Ultra Plus||0.8||Deep dermis, subcutaneous|
Anatomy and Aging
The structural aspect of facial aging consists of both descent of tissues (due to gravity and chronic activity of the muscles of facial expression), and loss of volume (bone and soft tissue). These changes are in addition to changes in the skin, such as elastosis, irregular pigmentation, roughness or dryness, telangiectasia, atrophy, deep wrinkling, and a variety of neoplasms. In the dermis, they include attenuation in number and diameter of elastic fibers in the papillary dermis, an increase in number and thickness of elastic fibers in the reticular fibers, and a coarsening of collagen fibers with an increase in density of the collagen network.
The SMAS and facial soft tissues are supported by several ligamentous structures. These include the orbitomalar ligament, zygomatic ligaments, masseteric cutaneous ligaments, and mandibular ligaments ( Fig. 19.3 ). The deeper muscles of facial expression, the zygomaticus major and levator labii superioris, also penetrate the SMAS and provide fixation.
The face undergoes generalized volume loss with aging, and squaring off of its youthful triangular shape. Superficial changes of the facial skin include brow ptosis, glabellar rhytides, malar festoons, deepening of the nasolabial fold and formation of melolabial folds (‘marionette lines’), smokers lines (circumferential rhytides around the mouth), jowl formation, and loss of lip volume ( Fig. 19.4 ). Midfacial ptosis is most likely caused by attenuation of the orbitomalar ligament rather than by sagging of the orbicularis oculi, zygomaticus major, zygomaticus minor, or the SOOF. Bulging of the lower eyelid fat due to weakening of the orbital septum combines with descent of the SOOF and cheek fat pad to produce a double convexity deformity, which is commonly referred to as the ‘tear trough.’
Clinical Indications, Physician Experience, and Patient Selection
The nasolabial folds are the area most commonly injected with NASHA fillers ( Fig. 19.5 ). This area has a high safety profile and a high patient satisfaction rate. The melolabial folds, jowls, and lips are the next areas that injectors expand into as they gain experience. Because of its slightly higher complication rate, the glabella is usually an area injected by injectors with expertise. This area requires a high degree of caution. With experience, the tear trough and brow may be injected.
Injection is contraindicated in the presence of infection at the injection site, in patients with prior history of hypersensitivity to NASHA products or Gram-positive bacteria, in minors, and in women who are pregnant or breast-feeding. Juvéderm ™ is the only product with FDA approval for injection in African-American patients, but we are unaware of complications in African-Americans after Restylane® or Perlane® injection. Patients need to understand the temporary nature of the injections, and realize that deep folds will improve with injection but will not be eliminated. Also, patients need to understand that although the injections should not appear lumpy, they will be able to feel the product and that at times it may feel lumpy. Patients need to be instructed to watch for signs of skin necrosis.
General Principles: Unless medically necessary, aspirin, NSAIDs, and other blood-thinning agents should be discontinued prior to injection. Patient counseling must be performed and informed consent obtained prior to injection. It is imperative to remove any make-up from the injection site. Depending upon the area, the physician may choose topical or local anesthesia, or both in combination. Topical anesthetic agents may include EMLA (AstraZeneca LP, Wilmington, DE), Betacaine LA (Theraderm, Tampa, FL), LMX4® (Ferndale Laboratories Inc., Ferndale, MI). Local anesthetic may be added in small volumes (e.g., 0.1 mL) to the filler vial itself.
Ice may also be used for 5 to 10 seconds prior to injection for anesthetic effect and vasoconstriction. After removal of any topical anesthetic, a thorough cleaning with alcohol swabs must be performed before injection. The label from the syringe should be removed and placed in the patient’s chart for traceability.
Proper injection depth and technique are filler specific. For most applications, Restylane® and Juvéderm ™ Ultra should be injected at the middermal level. Perlane® and Juvederm ™ Ultra Plus should be injected in the deep dermis or subdermal plane. If one sees chalky white blanching with intradermal injection, one should immediately stop injection as this signals ischemia and complete interruption of capillary blood flow (for management, see Complications at the end of this chapter).
Basic injection techniques
A number of techniques are used to inject NASHA into an area ( Fig. 19.7 ). The simplest technique, used by new injectors, is serial puncture. Multiple pinprick injections of filler are deposited at the appropriate depth. This is most commonly used as an adjunct technique to complete or ‘touch-up’ areas already filled using other techniques. Linear threading, perhaps the most commonly used technique, involves advancement of the needle and confirmation of uniform depth and appropriate location before depressing the plunger during withdrawal of the needle. The push-ahead technique involves advancing the needle while depressing the plunger. The flowing product acts to dissect ahead of the needle and push away surrounding blood vessels. Once mastered, this is an especially useful method for the vermillion border, and will reduce bruising in other facial areas. Cross-hatching involves the placement of parallel rows of product via the linear threading or push-ahead technique, followed by a second set of rows perpendicular to the first. This technique is the workhorse for nasolabial fold treatment. Fanning involves the placement of multiple radial linear deposits of product from a single entry site. This technique is useful for treating angulation and depression below the oral commisure.
Periodically during the injection, a wet glove can be used to palpate for smoothness of the injection and to identify lumps. Massage may be used to smooth out the product. The treatment is documented in the chart and the sticker from the syringe is placed in the patient’s chart.
After injection, patients are advised to avoid manipulating the filled area. Ice can be used to decrease postoperative discomfort and swelling. Patients undergoing perioral injections, especially those with a history of herpes simplex virus, are placed on oral antiviral prophylaxis after treatment. Patients should be instructed to call in cases of excessive swelling, redness, pain or itching, signs of necrosis, or persistent bumps.
Unless medically necessary, stop anticoagulation before injection
Ice before and after injection
Prep with alcohol swabs before injection
Use a wet glove to feel for lumps
Massage or use cotton-tipped applicator to smooth out lumps if necessary
Place the label from the syringe in the patient’s chart
Oral antiviral therapy is indicated after perioral injection, particularly in patients with a history of HSV