A randomized, split-face, histomorphologic study comparing a volumetric calcium hydroxylapatite and a hyaluronic acid-based dermal filler.

BACKGROUND

Soft-tissue augmentation with fillers is an aesthetic procedure for restoring age-related volume loss.

OBJECTIVE

To compare neocollagenesis and elastin production stimulated by Radiesse® (calcium hydroxylapatite; CaHA, Merz Pharmaceuticals GmbH) and a hyaluronic acid-based filler (HA; Juvéderm® VOLUMA®).

METHODS

Twenty-four women, aged 35-45, participated in this split-face, comparative study. Punch biopsies were taken 4 and 9 months after supraperiostal injection of each filler into the ipsilateral or contralateral postauricular area. Samples were analyzed for collagens type I and III, elastin, Ki-67, and inflammatory and angiogenic markers.

RESULTS

At month 4, collagen type III was greater with CaHA vs HA (P=0.0052). By month 9, type I staining was higher with CaHA vs HA (P=0.0135), whereas type III was lower with CaHA than HA (P=0.0019). Staining for elastin, Ki-67 and angiogenesis was greatest with CaHA at both timepoints. Inflammatory markers increased most with HA treatment.

CONCLUSIONS

CaHA resulted in more active, physiologic remodeling of the extracellular matrix than HA by stimulating a two-step process whereby collagen type I gradually replaced type III. Increased elastin stimulated by CaHA also indicates active remodeling. The results of this study suggest that, in the first 9 months after treatment, by reconstituting tissue homeostasis without inducing inflammation suggests CaHA has more desirable characteristics for a dermal filler than HA.