There are different methods for biostimulation and these include several modalities. The following are several methods: radiofrequency, microneedling, threads, resurfacing lasers, poly L lactic acid, and calcium hydroxylapatite.
Let’s talk about injectable fillers specifically, the two on the market are poly-L lactic acid aka Sculptra: comes in powder formulation as a synthetic polymer of lactic acid that is biodegradable. The second is calcium hydroxylapatite aka Radiesse: 30% calcium + 70% carboxymethylcellulose / glycerin gel carrier. They are very similar in nature with minor differences.
The mechanism of action of Radiesse gel lasts approximately 6 months and becomes phagocytosed then a collagen and elastin network are left behind. Collagen continues to build for up to 18 months. The gel carrier and spheres form a scaffold to propagate conversion of Type 3 to type 1 collagen. Thereafter, there is thickening of the skin (collagen): 15% by 4 months and 30% by 6 months. There is also tightening of the skin (elastin) 20% at 3 months and 40% at 7 months. The indications on label and off label are: To treat skin laxity, striae, +/- cellulite. Indicated areas for treatment are face, neck, chest, hands, decollete, periumbilical region, posterior upper arms, superior knee region.
The dilutions vary per area. There is a difference between dilute versus hyperdilute radiesse. Diluting and hyperdiluting removes the volumization component and increases biostimulatory effects. On-label Radiesse = lift and definition then collagen stimulation. It improves texture and quality of skin through at least 7 months post treatment. Dilution ratios vary per area treated. There is more collagen production with lower dilutions as there are more gel spheres per centimeter squared.
The studies were done with 2-3 sessions 4 months apart. In practice, I do 3 sessions 6 weeks apart. The reason why is because I think it’s hard to maintain patient rapport with a large gap follow up. The way I perform this procedure in practice is with a 22 G, 2 inch cannula Dilute with Lidocaine or Saline immediately after mixing (the higher the dilution, the faster the product separates). This must be done in a sterile mixing environment. The plane of injection is the deep dermis. You want to see the grey of the cannula to be in the right plane. Remember that feeling resistance is normal. I use 5 or 10 cc syringes to mix and female to female connector to dilute/hyperdilute. There should be at least 20 passes for homogeneity. Then you place the product back to the original syringe or 3 cc syringe to inject. The dilution ratio depends on dermis thickness. The following are the different dilution ratios: pan-facial rejuvenation 1:1, neck 1:2-1:4, decolletage 1:2-1:4, upper arm laxity 1:2, abdomen 1:1, buttock (sagging) 1:2, cellulite 1:1, striae 1:1, formula– 1.5 cc aka 1 syringe per 100 cm2 (size of a small hand).
The mechanism of action for poly-L lactic acid (PLLA with carboxymethylcellulose and mannitol) is a synthetic polymer local and subclinical inflammatory response recruiting macrophages, monocytes and fibroblasts. Hydrolysis occurs and products byproducts are eliminated over time. This inflammatory response leaves behind an increased collagen by fibroblasts. These results last generally 18-24 months. The indications are for the face and off-label areas are all similar areas to calcium hydroxylapatite. I inject Sculptra in 2-3 sessions, 4-6 weeks apart. The reconstitution occurs 24-72 hours prior with sterile water. I inject into SQ plane. Then I massage the area after treatment for proper dispersion. The dilution ratio for the face that I use is 2 ml lido, 8 ml sterile water. Post-procedure for both biostimulatory fillers, the recommendations are massage 5 minutes, 5 times per day for 5 days. Adverse events include Microspheres aggregate and cause delay onset nodules Bruising, swelling, pain, induration.
A tip for Sculptra injection is to place the vial inside a mug with warm water to keep the substance homogeneous. Other tips to consider when you’re first starting is to increase the dilution.
Denisse Serrano, PA-C
Co-Aesthetic Education and Social Media Chair
Diversity in Dermatology
Recommended Reading:
- Global Consensus Guidelines for the Injection of Diluted and Hyperdilute Calcium Hydroxylapatite for Skin Tightening.
By: Kate Goldie, MBChB; Wouter Peeters, MD; Mohammed Alghoul, MD; etal. - Consensus Recommendations for the Use of Hyperdiluted Calcium Hydroxyapatite (Radiesse) as a Face and Body Biostimulatory Agent.
By: Ada Trindade de Almeida, MD; Vinicius Figueredo, MD; Ana Lúcia Gonzaga da Cunha, MD; etal. - Recommendations on the Use of Injectable Poly L Lactic Acid for Skin Laxity in Off-Face Areas.
By: Alessandra Haddad, MD, PhD; Antonio Menezes, MD; Chrsitine Guarnieri, MD; etal.