INTRODUCTION
Advancement in aesthetic research and technology has resulted in development of numerous cosmetic products, including dermal fillers used for soft-tissue augmentation. Such fillers provide physicians and patients ample options for various non-invasive aesthetic treatments.1,2 With ongoing development, practitioners began requesting information on product composition required to achieve the highest lift, to provide the best reduction in volume loss, and to induce optimal biostimulatory effects, for example, while also considering the patient's aesthetic condition, anatomical structure, and treatment preferences.3,4 Furthermore, different dermal fillers meet different patient and provider needs - some add volume, some fill wrinkles, folds, or other hollows, some have an immediate volumizing effect, and some require time to properly augment a particular aesthetic condition. A single product cannot be considered as most effective or superior to other products.5,6
Commonly used dermal fillers are gel-like substances consisting of either hyaluronic acid (HA) or calcium hydroxyapatite (CaHA) microspheres suspended in a fluid phase. Due to its favorable rheological properties, CaHA has been widely used for volume-loss correction and natural collagen stimulation and, most importantly, for its long-lasting effect.1,2 CaHA activates collagen, elastin formation, and angiogenesis approximately 4 to 9 months following injection;7,8 CaHA's duration ranges from 9 to 18 months, compared with HA fillers that degrade within 4 to 6 months.1,4,9
Commonly used dermal fillers are gel-like substances consisting of either hyaluronic acid (HA) or calcium hydroxyapatite (CaHA) microspheres suspended in a fluid phase. Due to its favorable rheological properties, CaHA has been widely used for volume-loss correction and natural collagen stimulation and, most importantly, for its long-lasting effect.1,2 CaHA activates collagen, elastin formation, and angiogenesis approximately 4 to 9 months following injection;7,8 CaHA's duration ranges from 9 to 18 months, compared with HA fillers that degrade within 4 to 6 months.1,4,9