Comparative study of the penetration force between the superficial and deep temporal fascia for easier temple augmentation technique using hyaluronic acid filler

Abstract

<h2>Summary</h2> Temple augmentation is one of the most widely performed filler procedures. Multiple filler layers are recommended for temple augmentation. Filler injection into the space between the superficial temporal fascia (STF) and deep temporal fascia (DTF) is recommended to create one of the layers. However, it is not easy to identify the exact desired location for filler injection using a cannula tip. In this study, the difference in cannula penetration force (PF) was investigated to identify the easier procedure for filler injection. This study aimed to compare the forces required to penetrate the STF and DTF during temple augmentation. Twelve hemiface cadaveric specimens were used to clarify the structures of the STF and DTF. The PF of the retracted STF and DTF were measured. At the upper point, the mean PF of STF and DTF were 7.5 ± 2.9 and 13.2 ± 3.2 N, respectively. At the lower point, the mean PF of the superficial layer of the DTF was 11.5 ± 3.3 N. This study revealed that the forces required to penetrate the STF and DTF differed significantly. This suggested that a clear understanding of the layered structure of the temple area and the distinction of each structure during the procedure can accentuate the efficacy and safety of the temple augmentation procedure.