Do you hate the creases and lines in your face? What about your thin lips and furrows? Do you feel that you have deep nasolabial folds?

Do you want to get rid of them in 30 minutes and return to work without any one knowing what you had done?

DR MICHELE KOO, MD, FACS, BOARD CERTIFIED PLASTIC SURGEON, ST LOUIS, MISSOURI can help you regain a fuller, less wrinkled face giving you back the youthful volume of your face without the down time.

For individuals seeking facial rejuvenation, injectable dermal fillers offer a viable nonsurgical option. At the 2008 annual meeting of the American Society of Plastic Surgeons, various applications for dermal fillers were discussed. These included a hyaluronic acid (HA) gel filler, calcium hydroxylapatite, poly-L-lactic acid (PLLA), and collagen-based products.

Greater understanding of age-related facial changes has resulted in the growing use of soft-tissue facial dermal fillers. Recently, the focus has shifted towards a three-dimensional approach, emphasizing restoration of lost facial volume through the use of a variety of injectable dermal fillers that ideally afford patients a natural, relaxed, more youthful appearance.

Dermal fillers are appropriate for the correction of both dynamic and static fine, moderate, and deep dermal lines. It is extremely important to note, however, that each filler is approved by the US Food and Drug Administration (FDA) for a specific and limited anatomical area and a specific use. Also, the use of fillers for the correction of lines in other areas, as well as restoration of facial volume lost in the aging process, although effective, is off-label. In fact, such fillers are used off-label the majority of the time.

Types of Dermal Fillers

Hyaluronic Acid Fillers

As a class, HA dermal fillers have quickly become an extremely popular option in minimally invasive cosmetic procedures, second only to botulinum toxin injections. HA is a naturally occurring polysaccharide found in connective tissue and synovial fluid. The various hyaluronan products currently available have differing properties that influence their duration of effect and adverse-effect profiles.  Specifically, they may differ in the degree of gel hardness or flow properties, particle size within the gel, concentration of HA particles and gel per milliliter, and ratio of soluble to insoluble HA. Different injection techniques, including “cross-hatching,” “fanning,” “serial puncture,” and “linear threading,” are recommended for specific areas of the face and for specific products. It is important that clinicians know which techniques and needle sizes are most appropriate for the selected product and facial area to be injected.

Drs. Pinsky, Goldman, and Boyd discussed the final efficacy, safety, and patient-satisfaction results of a new-generation HA gel filler. In an open-label trial, 9639 subjects were treated with a new smooth, cohesive, 24-mg/mL bacterially derived HA to correct moderate-to-severe nasolabial folds. Evaluation at 9 months post treatment found the new HA gel to be safe and effective, with high patient satisfaction and preference.

With a variety of products available, it is of paramount importance for clinicians to choose the correct product to achieve the desired effect in the specific facial area. Less viscous products are appropriate for the upper dermis, whereas larger-particle products may be preferred for deeper grooves or folds. Some products contain local anesthesia, but patients still may benefit from separate anesthesia (ice, topical anesthetic, field block or peripheral nerve block) prior to the injections. After injections, it is often recommended that the clinician gently massage the treated area to smooth and mold the material and that ice packs be applied by the patient at home. Finally, unlike other dermal filler materials, asymmetries associated with the use of HAs can be corrected with the use of hyaluronidase.

As with all dermal filler products, touch-ups may be necessary after the initial treatment session. A presentation by Cukurluoglu and colleagues highlighted the importance of informing patients of the possible need for touch-ups, particularly in the nasolabial sulcus, malar, and lip areas.

Calcium Hydroxylapatite

Calcium hydroxylapatite provides a filler effect of generally longer duration than the HA products, with its cosmetic effect persisting between 6 and 12 months. It is typically injected subcutaneously into the nasolabial fold or areas requiring deep soft-tissue applications, but is not appropriate for use in and around the lips owing to possible nodularity. Calcium hydroxylapatite is currently indicated for use in oral/maxillofacial defects, vocal cord insufficiency, and radiographic tissue marking, as well as cosmetically for the correction of folds and wrinkles such as nasolabial folds. It is awaiting approval for the correction of HIV-related facial lipoatrophy. Autogenous collagen forms around the injected calcium hydroxylapatite to hold it in position and maintain the result.

Fakhre and coworkers reported results of a meta-analysis and patient-centric outcomes study examining patient satisfaction with calcium hydroxylapatite for cosmetic nasolabial fold correction. The meta-analysis standardized patient-satisfaction results to a 5-point scale (with 5 representing the greatest level of satisfaction) derived from 5 studies involving a total of 324 patients. Results from the 28 surveys that were returned indicated that patients perceived their results to be in the good-to-very-good range at 1 week (mean, 3.4), 1 month (3.7), and 6 months (3.1), but considered their results fair (2.3) at 1 year. The investigators concluded that calcium hydroxylapatite affords a high level of patient satisfaction in the short term, but that the level of satisfaction does not persist over 1 year post treatment even though the hydroxylapatite itself does.

Poly-L-Lactic Acid

PLLA is currently approved by the FDA for the restoration and/or correction of the signs of facial lipoatrophy in patients with HIV. In addition, it is used in Europe and off-label in the United States for long-term contour (or large-volume) restoration in healthy patients.  PLLA is injected subcutaneously at 4- to 6-week intervals for a total of 2-5 treatment sessions; reports suggest that the results persist for up to 40 months. After a brief injection reaction causing volumizing effects, results do not become apparent for up to 2 months after the last treatment. PLLA is most appropriate for large-volume restoration in the cheeks and has also been used for cosmetic enhancement in the chin, temples, and infraorbital region. The most common adverse events associated with PLLA injections include nonvisible, palpable subcutaneous nodules and granulomas.

In a study (N = 233) presented by Fredric Brandt, MD, that compared the efficacy of injectable PLLA vs a commercially available human collagen implant in the treatment of nasolabial fold wrinkles, there was overall improvement in over 88% for subjects treated with injectable PLLA. For patients who received human collagen implant, there was an overall improvement in 95.7% of patients (P < .001).The former group had significantly fewer postinjection product-related or injection-related adverse events reported among patients receiving PLLA vs collagen (P < .05 and P = .005, respectively).

Collagen-Based Products

Collagen-based products were among the original formulations used for soft-tissue augmentation. The need for hypersensitivity testing associated with bovine collagen led to the development and introduction of human-based collagens, which do not require allergy testing. Collagen injections are safe, but the effects are very temporary, persisting for only 3 months. Consequently, patients must undergo additional collagen injection treatments every few months to maintain the desired look.

Gordley and colleagues reported on a long-term assessment that compared 3 popular collagen-based products in the in vivo murine model: 2 materials involve a cadaveric dermal matrix and the third involves a porcine dermal matrix. All 3 products demonstrated similar encapsulation, peripheral infiltration, and surrounding inflammation upon histologic assessment. However, there was substantial variation between the 3 products on macroscopic evaluation, which likely caused the observed significant long-term variations in graft consistency and structure.

Combination Treatment

Aging influences many aspects of the underlying facial structure and external facial appearance, manifesting as wrinkles or furrows, changes in skin texture and color, and sagging. It is therefore understandable that a combination of therapies might be necessary to optimize the results of cosmetic rejuvenation. Combination approaches (all of which are off-label uses) can include layering dermal fillers at different depths and/or combining the use of dermal fillers to provide volume with neurotoxins, such as botulinum toxin A, to decrease muscle movement. Areas especially amenable to combination therapy include resting glabellar folds, horizontal forehead lines, nasojugal folds, and facial contouring of the zygomatic or perioral regions. Each product targets a specific area and concern, and combining them appropriately can optimize results by affecting both the dynamic and static components. In fact, it is now common for multiple areas to be treated in a single session.

Facial Areas Where Dermal Fillers Are Used

The face is typically divided into thirds when formulating a treatment plan: upper, middle, and lower. After this initial step, it is important that clinicians evaluate the entirety of the face, recognizing how rejuvenating one area may affect the appearance of other areas.^[1] Clinicians must consider the individual’s needs, skin color, skin type, and facial shape, including extent of intrinsic and extrinsic facial aging.

Facial areas most amenable to correction with dermal fillers, besides the cheeks, are the nasolabial folds, periorbital area, prejowl depression, and perioral area. Monotherapy with botulinum toxin has historically been the treatment of choice for the upper face, but the addition of HA to botulinum toxin (either in the same treatment session or a subsequent treatment session) affords greater aesthetic improvements and nearly doubles the median duration of response. However, HA injections to the upper face should be performed by experienced clinicians to avoid the rare yet serious complication of necrosis.

Many clinicians use multiple dermal filler products depending on the need of the patient. Correction to the midface region is dependent upon the degree of facial volume loss. Botulinum toxin is often a secondary treatment to dermal fillers in this region, in contrast to the upper face. For correction of the nasolabial folds, clinicians recommend using more viscous filler products via fanning or linear threading techniques for flattening medial to the crease; less viscous products are typically used for the more superficial fine crease itself through serial puncture or linear threading. Because marionette lines and prejowl depressions are more superficial lines, they are typically addressed by mid-to-deep dermis injections using linear threading or serial puncture. Prejowl depressions may require deep subcutaneous injections. Fillers are often added to neurotoxins in and around the periorbital area, where deeper injections are recommended in order to avoid lumpiness.  Because the goal for correcting the lips or perioral rhytides is typically to provide fuller, more voluptuous lips, serial puncture and threading techniques are recommended.

Optimizing Treatment and Safety Considerations

Clinicians must be familiar with (1) which injection techniques and placements are used for each product; (2) the recommended follow-up treatments; and (3) which facial regions are indicated for each specific filler. Patient demographics have also expanded to include substantially more ethnic minorities and males. Differences in musculature between males and females can influence dosing needs and injection technique/placement. Skin color can affect underlying structure and architectural differences, as well as responses to ultraviolet damage. Clinicians must consider all of these factors — intrinsic and extrinsic aging, gender, ethnicity/skin color — before developing an individualized plan for facial rejuvenation. Finally, early complications associated with dermal fillers are typically transient and self-limited, including bruising, edema, and swelling around the injection sites. Although rare, there is the possibility of hypersensitivity reactions, asymmetries, and lumpiness, with longer follow-up of longer-lasting fillers sometimes revealing troublesome and deforming granuloma formation.

Conclusions

Injectable dermal fillers have become an important component of the aesthetic clinician’s armamentarium. The wide variety of dermal filler products allows clinicians to optimize desired results by individualizing patient treatment plans and using combination therapies when appropriate. Having a choice of products necessitates knowledge and comfort with the numerous options, particularly when products are used off-label. Appropriate patient selection, proper injection technique, and selection of the most appropriate product for the desired result in the targeted facial area(s) are key factors underlying patient satisfaction and product efficacy and safety.