Until recently, the only filler approved for use in the United States was bovine collagen (Zyplast® and Zyderm®).

However, several new fillers for facial lines, wrinkles, and creases are now available. Hyaluronic acid products previously approved in Europe and Canada provide significant improvement of age-related facial lines and creases and offer malleable products with long-lasting results. The availability of several types of products allows multiple fillers to be combined in one procedure.

Successful fillers of the future will include long-term, short-term, and medium-term fillers that may be used alone or in combination. For example, long-lasting fillers such as fat, Perlane®, Radiance®, Radiesse®, or Artefill® may become fillers of choice for the nasolabial folds, while a shorter-term fillers may be used in the lips.

What types of fillers have recently been approved?

Human collagen (Cosmoplast®, Cosmoderm®) was a step up from bovine collagen in many ways-a clean, safe alternative that did not require any skin tests. Immediate results are the main advantage of human collagen, despite it being more expensive than bovine collagen and not as long lasting as some newer filling agents.

In Europe, many non-collagen-based fillers have been developed. The most exciting so far is hyaluronic acid. Restylane®, an FDA-approved product, uses non-animal stabilized hyaluronic acid (NASHA). The two other NASHA products are Restylane® Fine Lines and Perlane®, neither of which is FDA approved. The difference between the three products is the size of the particles, with Perlane having the largest particles followed by Restylane®, and then Restylane® Fine Lines.

Hylaform® (Inamed Aesthetics, Inc.), a hyaluronic acid product FDA approved in April 2004, is derived from rooster combs. Allergic reactions are extremely rare with any type of hyaluronic acid product, and skin tests are not required.

The advantages of these products include no delay in receiving treatments and much longer-lasting results than collagen-perhaps as much as one and a half to two times as long. Instead of two to three months with collagen, Restylane® lasts approximately six months and Perlane® lasts six to eight months.

Another significant advantage is that hyaluronic acid products such as Restylane® and Perlane® are malleable-they remain soft and compressible for three or four months after treatment. If lumps form, they can be removed with pressure and molding.

The one disadvantage of hyaluronic acid is that because water is drawn to the molecule, it tends to cause almost immediate swelling, which can last one to three days after treatment. Swelling is especially prominent in lips and less so in the nasolabial folds.

On the horizon

Artefill® was submitted for FDA approval in 2003 and although it has received preliminary approval, it has not been approved. This product consists of polymethyl-methacrylate (PMMA-lucite) microspheres in 80 percent bovine collagen. The collagen eventually disappears, leaving the lucite microspheres. It has been available in Canada and Europe for over five years and is effective for nasolabial folds. The disadvantage is that the patient may be able to feel lumps and reactions sometimes occur. It does require skin testing and is considered permanent.

Radiance® (BioForm Medical, Inc.) is another filler that has recently received a lot of attention, but has not received FDA approval as a filler. It consists of microspheres of calcium hydroxyapatite in a gel of sodium carboxymethylcellulose, glycerin, and water. The patient's own tissue replaces the gel, and the microspheres remain. It is considered permanent. Results thus far have been encouraging in the nasolabial folds but not in the lips. BioForm Medical Inc. has recently gained FDA approval for Radiesse®, a form of Radiance®, for cosmetic surgery.

Many patients oppose products that last longer than a year because they are worried about their face changing shape or that they will no longer like the results. An effect that lasts longer than a year is not necessarily better because permanent fillers may have permanent side effects. Injectable silicone is a product that has been around for a long time, but has never been approved for use as a filler. Silicone shows promise as a treatment for nasolabial folds, lip enhancement, and for acne scars. No standard has been established for medical-grade silicone and purity, sterility, viscosity, and injection technique must be carefully considered.

Another product recently approved by the FDA is Sculptra® by Dermik Laboratories, the U.S. dermatology arm of Aventis. This synthetically derived product promises to be a long-lasting, dermal contouring agent that can be used to help restore lost facial volume in people with lipoatrophy.

Autologous fat injections

The use of fat transplantation has several advantages; it is pliable and moldable, provides bulk, comes from the patient's own body, and is long lasting. However, fat also has several disadvantages. The surgical harvest procedure is technique-sensitive and can require multiple touch-up procedures. Injections can be painful. The results, however, can be impressive, especially in patients suffering from atrophy of the cheeks and redistribution of fat due to aging.