The approval of bovine collagen injectable heralded a new era of soft-tissue augmentation. The number of approved soft tissue fillers in the United States and Europe has continued to grow rapidly in the last decade. Hypersensitive reactions were common occurrences in bovine collagen use, which led to the development of bioengineered human collagen. Hyaluronic acid (HA) displaced human-derived collagen’s place in the market due to the latter’s limited duration of effects and different flow characteristics. Up to this day, hyaluronic acid-based fillers are 1 of the most widely used soft tissue implant worldwide.
How to choose the right filler:
1. Particular defects or area to be treated: lighter molecules are recommended for superficial wrinkles and mild defects, while denser molecules are best for volumizing and augmentation.
2. Desired outcome and duration: semi-permanent and permanent fillers are preferred for longer duration.
3. Material: some products require pretesting for hypersensitivity reactions (i.e. collagen-based fillers)
Different kinds of fillers
Collagen is an essential protein found in supporting body tissues such as skin, tendons, and ligaments. It helps maintain the rigidity of these structures, however, its volume and quality diminish with age. Collagen dermal fillers was the most popular injectable used for filling soft tissue defects for many years—creating minimal inflammation and post-injection complications. Collagen derived from cows was popular in the 1980s but was eliminated in the market due to allergic reactions in suceptible individuals. Bioengineered human collagen supplanted bovine –derived collagen because of less anaphylactic risk.
HA is a natural component of the skin, joints, and other connective tissues. It is widely regarded as the best dermal filler to date, owing to its flexibility, fewer risks involved, and temporary effects that can be corrected or enhanced. While some dermal filles require overcorrection to compensate for the anticipated loss of fill due to rapid absorption of the material used, experienced provider tend to undercorrect with regards to HA fillers. Mainly because the hyaluronic acid in these fillers tend to aborb large volume of water and bulk the treated area over several weeks.
This natural mineral substance is an important component of the bones and teeth. It has been approved as a semi-permanent filler for correcting moderate to severe wrinkles (e.g., nasolabial folds), HIV facial lipoatrophy, and recently, even hand rejuvenation. Currently, Radiesse is the only approved preparation for this filler. It is being used off-label for facial volumization, cheek, chin, and lip augmentation, and jaw recontouring. No skin testing is required prior to administration. This filler has been reported to last for up to 5 years, but the average duration is 12–18 months.
Polylactic acid (PLLA)
Sculptra has been initially approved for correcting HIV facial lipoatrophy but it was later expanded to filling lines and correcting contour deficiencies in 2009. PLLA fillers is a sythetic material contained in microsphere beads. The area might appear too “plump” immediately after injection, but it gradually disappears within a few days. It creates long lasting benefits.
Polymethymethacrylate (PMMA) beads
PMMA fillers last more than 5 years hence considered as a permanent filler. It comes in a suspension form containing 20% PMMA beads suspended in 80% bovine collagen. It was FDA approved for correcting nasolabial folds. Granulomatous reaction is 1 of its pitfalls.
Why use cosmetic injectables?
- The majority of approved fillers have good safety profiles that are well documented in literature.
- The addition of lidocaine in a number of preparations facilitates pain-free injection.
- They are formulated to treat specific areas of the face, lips, neck, and hands.
- It creates dramatic visible results that cannot be replicated by topical cosmoceuticals.
- It is minimally invasive but provides long lasting results.
- Unwanted effects or overcorrection can be reversed.
- It can be combined with other dermatologic treatments for optimal results.
- It is a fast growing market and research studies are continuously being conducted to hasten the approval of emerging products.
- Athough minimal in most available fillers in the market, allergic reactions can still occur from animal-derived products (e.g., bovine collagen), and other sources such as chicken egg white or streptococal proteins.
- Minor injection reactions are common in up to 90% of patients during the first 2 weeks. These include bruising, swelling, redness, tenderness or pain, and lump formation.
- Unintended injection into blood vessels may cause necrosis, embolization, and retinal occlusion.
- Uneven or asymmetrical results are also common but can be prevented with proper injection techniques or injecting hyaluronidase to correct the imbalance.
Are there any risks of using fillers?
Even popular fillers are not without concomitant risks, but side effects are often minimal and transient in properly placed dermal fillers. Incompetent medical providers and the use of unknown substitutions often cause serious complications. That being said, there are a number of fillers that are trusted and widely used by doctors around the globe.
Dermal fillers are medical devices that are safe and efficacious in rejuvenating aging skin. Hyaluronic acid-based fillers is the mainstay in wrinkle reduction and temporary volume restoration. Structure and composition with respect to implantation area and diffusion affect the result and longevity of the treatment. Suitable patient selection and matching appropriate fillers for the patient’s skin condition are important for the final cosmetic outcome.