In our day-to-day life, it is important to look the best that we can, at any age. As we age, our faces lose soft tissue volume and undergo skeletal resorption causing deflation and descent, manifesting in wrinkles and folds. Hence, a lot of people feel what they look on the outside is not what they feel on the inside. Looking young and fresh is becoming important in our social and professional interactions as looking good is associated with positive vibes from others. And it is not sex-specific. Both men and women want to look better and younger. A variety of procedures are available such as botulinum toxin, dermal fillers, chemical peels, lasers and cosmetic surgery. The non-surgical procedures are usually preferred over the surgical ones.

Of the non-surgical treatments, dermal fillers have revolutionized the field of aesthetic medicine. They are increasingly being used by dermatologists and plastic surgeons to diminish or correct the signs of aging. Fillers offer highly gratifying results due to immediate correction of rhytides, lift, enhancement of contours and filling up of hollows.

The first fillers that were approved for clinical use were made of bovine and porcine collagen. However, the results were short-lived, with a potential risk of foreign body reaction with the non-human sources.

By definition the perfect dermal filler should be safe, painless, easy to inject, hypoallergenic, long-lasting and economical. It should also give smooth, natural looking results and feel natural under the skin. Hyaluronic acid (HA) fillers satisfy most of these criteria making them the most common choice of filler and they have now become the gold standard in fillers. Hyaluronic acid binds to water and swells, thereby it volumizes, softens and hydrates the skin. It acts as a matrix for fibroblasts, stimulating the production of collagen which partly contributes to its long lasting effects. Because hyaluronic acid molecule is identical across all species, the risk of allergic reactions is remote. Another advantage of using hyaluronic acid fillers is its ease of correction with hyaluronidase, in case of undesirable outcomes or adverse effects. Most of the newer hyaluronic acid fillers now contain lidocaine, which helps reduce the pain of injection and discomfort of moulding the filler.

HA used in practice today is derived from bacterial cultures of Streptococcus bacteria by biofermentation.

HA fillers can be used to:

• Plump thin lips
• Enhance contours eg. of the cheek, jawline and chin
• Soften facial creases and wrinkles
• Improve undereye hollows and dark circles
• Rejuvenating the back of the hands
• Improving the hydration of skin on the face, neck and hands
• Hand rejuvenation
• Non-surgical rhinoplasty

Brands approved for use in India are:

1. Restylane family of products, which includes Restylane, Perlane, Restylane with lidocaine, Perlane with lidocaine and Restylane vital. This group of products contains particles of cross-linked hyaluronic acid suspended in a non-crosslinked hyaluronic acid gel (biphasic gel). The HA concentration is 20 mg/ml in all the products, but the particle size varies with each product. This makes them one of the stiffest hyaluronic acid fillers. Results last for 6-9 months on an average. Restylane vital is used to enhance the texture and softness of the skin, and is called a skin booster.
2. Juvederm family of products includes Ultra XC, Ultra plus XC and Voluma XC. Juvederm is a homologous (monophasic) gel with the high degree of cross-linking giving it a smooth consistency. Ultra XC & Ultra plus XC use the Hylacross technology of cross-linking and have 24mg/ml of HA. Their tissue life is about 6-12 months. Voluma XC uses the Vycross cross-linking technology and has 20mg/ml of HA giving it excellent firmness and pliability. The XC range contains lidocaine to reduce the injection pain. The longevity is about 18-24 months.
3. Esthelis family of products includes Esthelis, Fortelis, Modelis and Mesolis; with HA concentration is 22.5 mg/ml, 25mg/ml, 26 mg/ml &14 mg/ml respectively. Esthelis, Fortelis and Mesolis are approved for use in India. They are monophasic gels with an extra degree of cross linking (cohesive polydensified matrix) except Mesolis which is not cross-linked. Longevity ranges from 6 to 18 months depending on the density of the product.
4. Emervel lip and Emervel volume have recently been approved for use in India. It has 20 mg/ml of HA, and is biphasic filler similar to Restylane. Results last for 6 to 12 months.
5. Yvoire classic and Yvoire volume have recently been approved for use in India. The HA concentration is 22mg/ml. It is a biphasic filler with results lasting for 6 to 12 months.

Injection Techniques

They vary from filler to filler. Most common techniques are serial puncture or bolus technique and, linear threading which could be anterograde or retrograde with or without fanning. They can be administered via needle or cannulas. Cannulas are fast gaining popularity among doctors when it comes to treatment of certain areas such as tear trough, cheek, hands. The chances of bruising are less with cannula and larger areas can be treated from a single point, reducing the pain of treatment.

Fillers of varying softness can be placed at different levels in the tissue (sandwich technique) to provide a more natural looking result. Softer fillers are placed more superficially and denser fillers, deeper for a desirable cosmetic outcome.

It is important to be individually trained on the injection techniques of each filler. It is of paramount importance to know the anatomy of the facial skeleton, soft tissues and the neurovascular structures to ensure product placement at the right level and prevent any complications from inadvertent injury.

Considerations in choosing an HA filler:

1. FDA approval
2. Cost
3. Duration of correction
4. Ease of injection
5. G prime (G’) or gel hardness – Harder gels like Perlane or Juvedermvoluma are placed deeper in tissue or over the bone whereas softer gels like Restylane, Esthelis or Ultra XC are used on the undereyes and lips.

Adverse effects:

1. Swelling, erythema & bruising are commonly seen after procedure. These are self-limiting and subside within a week or two. Good injection practices can minimize these events. Use of a cannula has reduced the incidence of bruising.
2. Pain during the procedure can be minimized by injecting slowly. Products that contain lidocaine reduce the discomfort of the procedure and make molding of the filler quite comfortable.
3. Tyndall effect: If fillers are injected too superficially they can create a bluish hue due to the Tyndall effect.
4. Vascular compromise: Although rare, it is one of the most severe side-effects of filler procedure. It can occur due to compression or inadvertent intra-arterial injection of the filler. Compression manifests a few days after the filler procedure with pain at site of injection redness along the site and distribution of the vessels due to opening up of collateral circulation. Intra-arterial injection of filler can result in severe pain and necrosis in the area supplied by the vessel. Treatment includes immediate injection of hyaluronidase in the filler treated area, and vasodilator therapy.
5. Nodules: Injection close to the surface or large boluses can cause nodule formation. It can also be a delayed phenomenon due to bacterial biofilm formation. They are treated by hyaluronidase into the nodule, with or without antibiotic therapy.
6. Poor cosmetic outcome can be corrected with hyaluronidase injection.

The demand for soft-tissue augmentation is slowly increasing in India. Newer products with better tissue compatibility and longer lasting results are becoming available. The current aesthetic practitioner will need to be aware of the current availability, application and future potential of dermal fillers.

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