Changes in skin quality include structural atrophy and functional defects of the epidermis and dermis caused by various reasons. These skin quality changes can manifest as dry skin and roughness, large pores, fine lines, acne scars and many more. Dermal injection of both non-cross-linked hyaluronic acid (NCLHA) and cross-linked hyaluronic acid (CLHA) can immediately increase the thickness and water content of the dermis and improve the skin quality, and thus, have become increasingly popular in clinics. Some animal experiments and human subject researches have shown changes in the dermal micro-environment after dermal HA injections, which induced continuous traction of fibroblasts and increased new collagen synthesis.
In comparison to NCLHA, the longer half-time and stronger expansion strength of CLHA provide a better and longer-lasting effect. Clinically, dermal injection of CLHA offers both rapid and long-lasting effects on improving skin quality. Since the injection layer is intradermal, the results are relatively safe with less serious adverse reactions such as vascular occlusion.
However, because different products have different and unique characteristics and the thickness of the skin also vary among injection sites, it is important that clinicians are very familiar with the products and are able to strictly control the depth and amount of injection in order to achieve optimal results. This presentation focuses on the mechanisms, injection indications and contraindications, standardized treatment protocol for different treatment purposes and injection sites, common adverse reactions and solutions for clinical reference.