The second class of injectable treatments is the soft tissue fillers. This group is rapidly expanding, and many options are available. These injectable fillers are more useful for treatment of firmly established wrinkles or larger lines of facial aging (such as the nasolabial folds). Fillers restore volume to the face and can add structure as well. Depending on the type of filler and the depth at which it is injected, you can smooth out fine lines on the surface of the skin, fill out deep lines (eg: nasolabial folds), augment soft tissues (such as the lips), or even effectively augment facial bone structure. All of these injectable fillers are placed by an injection, so the group carries usual risks of bruising, lumpiness, redness, product specific adverse reactions, and in rare cases local infections.
Many options are available in the filler class, with clinical differences being predominantly governed by how long the effects last, as well as how the filler “feels”. Generally speaking, very soft fillers (that are best for locations such as the lips) tend to have a shorter duration of effect, while fillers that last longer tend to have more structure and are better suited in regions where they will not be palpable (such as the nasolabial folds). In the past, the most widely used fillers were based on collagen, with sources ranging from bovine to human. For some collagen formulations, skin testing before injection is necessary to confirm that you will not have an allergic response to the filler. Collagen based fillers tend to last 3 to 6 months, and for some indications have a very natural feel.
A more recent class of fillers is based on hyaluronic acid (HA), a sugarwhichis found naturally in human skin. When first introduced, a major benefit of this filler class is that allergic reactions are extremely rare, and no pre-treatment skin testing is necessary. These compounds bind water similar to the way a sponge absorbs water. Because of this, they hydrate the skin in the treated region and act as a cushion. Several manufacturers are coming out with versions of HA fillers, and formulations vary with the size of molecules (governed by the
amount of crosslinking) and other components of the injectable (such as local anesthetic to help decrease the discomfort associated with injections). The various formulations expand the repertoire of options available to your injector, as certain products are better suited for different anatomical regions. Formulations with smaller particle sizes tend to be softer and smoother, and work well in regions such as the lips. Larger particles have more structure, and are best suited for deep folds such as the nasolabial creases. Hyaluronic acids are eventually absorbed by your body, and the length of time is dependent on a multitude of factors including the patient, the location of injection, and the particular product used. Results last from 3 months in high mobility areas (such as the lips), and up to 1 year in regions such as the nasolabial folds, with most patients experiencing the desired effects for 6 months.
A newer class of fillers has been introduced that is based on microsphere technology. Microspheres are tiny round particles of solid material that are relatively uniform in size. Two formulations are FDA approved for use, differing in design and expected longevity of results. These products are used for volume replacement and for deep facial wrinkles (such as the nasolabial folds.) They are not approved for use in the lips.
Radiesse contains microspheres that are made of calcium hydroxylapatite suspended in a gel carrier. The filler is broken down by the body in two phases, first the carrier and then the spheres. During this process, collagen ingrowth occurs, which is expected to provide a long lasting effect. This prolonged degradation process makes Radiesse a longer lasting filler than those previously discussed, with expected results lasting a year or more.
Artefill is filler made of a mixture of collagen gel (similar to classical dermal fillers) and tiny microspheres of non-resorbablepolymethylmethacrylate (a biocompatible compound that has been used for years in orthopedic surgery). The collagen component has resorption characteristics similar to other collagen based fillers, but the microspheres cannot be degraded by the body, and should provide permanent support to the regions treated. Since this type of filler is permanent, the margin for error in placement is less than for resorb able fillers, and it is important to seek treatment by an injector with experience using this class of product.