Hyperdilute Calcium Hydroxylapatite for the Treatment of Perioral Rhytids: A Pilot Study

Abstract Background The perioral region plays a crucial role in facial aesthetics and is susceptible to age-related changes, such as wrinkles and fine lines due to its dynamic nature. Type I collagen is crucial in providing structural integrity and resilience to the skin. Calcium hydroxylapatite (CaHA-CMC) is a widely used dermal filler whose particles stimulate fibroblastic responses within the skin. When diluted, CaHA-CMC has emerged as a useful treatment for collagen stimulation. Objectives The objective of the study is to evaluate the efficacy and safety of hyperdilute CaHA-CMC at a 1:3 ratio, specifically administered in the perioral area, to assess its impact on deep rhytids and overall skin quality. Methods Females aged 40 to 70 years with moderate-to-severe wrinkles in the perioral region based on a validated wrinkle scale were injected with hyperdilute CaHA-CMC throughout the perioral region at 2 separate injection intervals (Weeks 1 and 8). This was followed by an injection of hyaluronic acid (CPM-HA22.5) into the perioral region at Week 16. The primary endpoint was a ≥1-point improvement from baseline on the wrinkle grading scale. Results Twelve female participants were treated. Investigator and patient ratings based on the 5-point Merz perioral/lip wrinkle grading scale showed at least 1 grade improvement in 83% of the patients with a P-value of .0156. A majority of both investigators and patients rated their lip wrinkles as improved in appearance compared with their baseline. Conclusions Hyperdilute CaHa-CMC at a 1:3 dilution may be a safe and effective treatment for improving the depth and overall appearance of perioral rhytids. Level of Evidence: 4