Injection of filler agents for facial rejuvenation is by no means a new procedure. Substances such as mineral oil, liquid silicone, collagen and even para n have been used as soft tissue filler to improve soft tissue imperfections.
Due to high incidences of complications, which includes chronic oedema, granuloma formations, lymphadenopathy, scarring and ulcer formation, new and safer products made from hyaluronic acid (HA) have been developed. With less complications, the demand for injectable fillers has grown in recent years as more and more clients seek non-surgical means for correcting age-related changes to their facial skin.
There are two types of wrinkles: dynamic and static. They can occur separately or in combination. Dynamic wrinkles appear when facial expressions are made, this is due to the contraction of the underlying muscles. Static rhytids, on the other hand, are lines that are present even in the absence of facial expressions -these are largely due to intrinsic changes and external factors such as smoking and sun exposure.
Wrinkle grade can be assessed using the Wrinkle Assessment Scale (WAS) which was developed by surgeons to assess the severity of wrinkles on a scale of 0-5.
The ideal fillers are those that are biocompatible, resorbable and non-carcinogenic. To ensure patient safety, it is always best practice to choose fillers that are well-researched.
The end result of derma filler treatments should be natural-looking, nonpalpable and long lasting.
Hyaluronic Acid Fillers
Hyaluronic acid (HA) is a naturally occurring glycosaminoglycan that is the building block of the dermis and a major component of all connective tissue. The chemical structure of this polysaccharide is uniform throughout all mammals. There is no potential for immunological reactions to HA in humans. The HA molecules in the skin bind water and create volume.
HA is a monomer that is composed of sodium glucuronate combined with N-acetylglucosamine. The HA filler is manufactured as a polymer that is composed of multiple monomers bound together like a string of beads. When HA is in a non-crosslinked form, it is essentially a liquid because the molecules are suspended individually in the solution. When HA is crosslinked, the liquid is transformed into a gel. The thickness of the gel correlates with the amount of crosslinking present in the compound. Other factors that affect the thickness of the gel include the concentration of HA as well as the sizing of the gel particles within the compound itself. The thickness of the gel is typically altered by adding non-crosslinked HA to crosslinked HA to thin the compound and increase ow. Another way this is accomplished is by adding smaller HA gel particles.
The amount of HA in the skin decreases with age and its subsequent loss results in reduced dermal hydration and an increase in skin wrinkles.