Soft Tissue Fillers
Injectable fillers are generally considered soft tissue augmentation materials. These injectables are more useful for treatment of firmly established wrinkles or larger lines of facial ageing (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 (e.g. nasolabial folds), augment soft tissues (such as the lips), or even effectively augment facial bone structure.
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 frombovine to human. For some collagen formulations, skin testing before injection is necessaryto 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.
Hyaluronic Acid Fillers
A more recent class of fillers is based on hyaluronic acid (HA), which is a sugar 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. 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 mirospheres 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.
Permanent injectable Micro-Implants
Artefill is a filler made of a mixture of collagen gel (similar to classical dermal fillers) and tiny microspheres of non-resorbable polymethylmethacrylate (a biocompatable compound). 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 resorbable fillers, and it is important to seek treatment by an injector with experience using this class of product.
This is done as an office procedure and needs no anaesthesia. Area to be filled is marked out and cleaned. Fillers which comes in prefilled syringes are carefully injected into the sites. The whole procedure takes only a few minutes and improved appearance is visible almost immediately.
Risks and Limitations
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. Also collagen fillers from non human sources require an allergy testing. Injecting Fillers may aggrevate asymmetry or may cause under /over correction. Temporary biological fillers have to be repeated periodically.