Safety and efficacy of the amino acid crosslinked hyaluronic acid in the treatment of temple hollowing

Loss of volume in the temples is an early sign of aging and often gives the impression of a gaunt and emaciated appearance. The authors conduct a clinical study to investigate the safety and effectiveness of the amino acid crosslinked hyaluronic acid (ACHA) for the treatment of temple hollowing. 75 subjects with Temple Hollowing Scale (THS) from 2 to 4 were enrolled and assigned according to the ratio of 2 (ACHA group, n = 50): 1 (no treatment control group, n = 25). All subjects were assessed at the 12-month follow-up visit using the THS, Global Aesthetic Improvement Scale (GAIS), ultrasound, and three-dimensional scanning. Subjects were instructed to report any adverse events (AEs) within 14 days after the ACHA treatment. An average volume of 4.72 ± 1.13 ml was injected into the temples. We received 18 treatment-related AEs reported by 10 subjects. Compared with the control group, THS, GAIS, and soft tissue thickness were significantly improved in the ACHA group at 1 month, 6, and 12 months after injection. Three-dimensional scanning showed that ACHA could maintain a certain volume in the temple 12 months after ACHA injection. ACHA is an effective and safe hyaluronic acid for patients with minimal to severe temple hollowing.