The general misconception since the new hyaluronic fillers have been approved is that they are replacing collagen fillers.

Patients who once opted to have collagen injections are often under the impression that they will switch to hyaluronic acid injections because they last longer.

While hyaluronic acids might last a little longer than collagen, in most cases, cosmetic surgeons will find there is no one-filler-fits-all-wrinkles approach.

Many cosmetic surgeons are instead using a combination approach, with collagen injections to address fine lines and hyaluronic acids to bulk the deeper wrinkles, according to Corey Maas, M.D., facial plastic surgeon, associate clinical professor at the University of California, San Francisco.

"We have patients who previously were not interested in fillers coming in as a result of the media attention surrounding the new hyaluronic acids, Hylaform (Inamed) and Restylane (Q-Med)," Dr. Maas says. "But we have to explain to them that the products are not necessarily interchangeable, and a combination of collagen and hyaluronic acids often produces the best result."

The thicker-viscosity hyaluronic acids approved in the United States are difficult to inject into upper layers of skin to address fine facial lines, including perioral lines. Injected into the superficial skin layers, the hyaluronic acid products might result in a translucent blister-like effect.

"With the collagen products you can actually get into the very top of the papillary dermis and really smooth out those lines," he tells Cosmetic Surgery Times.

Dr. Mass uses combination filler treatments of CosmoDerm 1 (Inamed) and either Hylaform or Restylane when patients have both fine and deeper lines that they consider problematic.

Choosing between hyaluronics Researchers have yet to conduct direct comparison studies of Restylane and Hylaform.

The studies done of the hyaluronic acids to gain U.S. Food and Drug Administration approval have looked at the comparability of hyaluronic acids and collagen products, according to Dr. Maas.

"All we really know from the true science that is out there right now is that both are at least comparable fillers to Zyplast (Inamed)," he says. "There is a lot of discussion about the duration of effectiveness of these products, and I can say from experience that probably Restylane lasts longer in general for the deeper applications than does Hylaform. The average is in the five- to six-month range for Restylane, and it is probably in the four-month range for Hylaform, which is a little longer than collagen."

Expense factor The factor that weighs in Hylaform's favor is that it is considerably less expensive than Restylane, according to Dr. Maas. Surgeons, he says, can use a 1cc syringe of collagen product — for example, CosmoDerm 1 — for the fine lines around the lip, and a 1cc syringe of Hylaform to do bulking of the lip, for less than what it costs for one syringe of Restylane.

Two steps to smoother skin When combining collagen and hyaluronic acid fillers, Dr. Maas first uses CosmoDerm for the superficial lines.

"CosmoDerm has local anesthetic in it to numb the area," he explains. "Then, we use Restylane or Hylaform in the bulk of the area."

Good indications for use of the combination fillers would be the lip and nasolabial fold.

In the typical aging lip, the patient will have a number of radiating vertical fine lines that extend from the lip border, he says.

"We will start with 1cc of CosmoDerm and fill those fine lines up to the lip border," Dr. Maas says. "By the time we finish that, the local anesthetic from the collagen will have numbed the lip area. We then use 1 cc of hyaluronic acid along the lip border and body of the lip. Using the hyaluronic acid after the collagen filler is a good way of re-establishing the lip roll and bulking it up."