Efficacy and Tolerability of Hyperdiluted Calcium Hydroxylapatite (Radiesse) for Neck Rejuvenation: Clinical and Ultrasonographic Assessment

BACKGROUND: The subdermal injection of calcium hydroxylapatite (CaHA) can improve the mechanical properties of the skin, providing immediate correction and stimulating the endogenous production of collagen, elastin, angiogenesis, and dermal cell proliferation; however, few studies have examined the neck region. PURPOSE: This study assessed the clinical and ultrasonographic improvement induced by two sessions of subdermal injection of hyperdiluted (1:4) CaHA for neck rejuvenation in 22 women. PATIENTS AND METHODS: A quasi-experimental longitudinal trial (before and after) was performed by enrolling 22 adult women with mild and moderate neck aging (grades 1 and 2) on Merz Neck Volume Scale at rest (laxity) and Neck Horizontal Lines. They were submitted to two sessions of subdermal hyperdiluted CaHA (D0 and D45) treatments and assessed clinically and ultrasonographically at D0, D45, and D120. The main outcomes were the blinded photographic assessment (Merz scales of neck laxity and horizontal lines), dermal thickness (at three points), and the GAIS (Global Aesthetic Improvement Scale) score. RESULTS: The mean (SD) age was 43.5 (5.6) years. At the inclusion, the Merz scores for neck laxity were mild for 27% and moderate for 73% of participants, and the Merz scores for necklines were mild for 32% and moderate for 68%. At D120, scores decreased in 86% (95% CI 68–99%) of the participants by at least one degree on the necklines scale and in 82% (95% CI 73–90%) for neck laxity. According to the GAIS, 91% (95% CI 77–99%) of the participants evidenced improvement at D120. The mean dermal thickness increased by 15% (95% CI 8–21%) at D120. No severe adverse effects were recorded, and high satisfaction was reported by 82% of the participants. CONCLUSION: Two sessions of subdermal hyperdiluted CaHA were well-tolerated and improved necklines, neck laxity, and dermal thickness in adult women with mild and moderate cervical aging.