Resumo

Objectives: This study evaluated the dual-depth targeting capability and the ability to induce rejuvenation in each layer of vertical skin anatomy, i.e., the epidermis, papillary dermis, and reticular dermis, using full-thickness human facial skin Introduction: A novel dual-length microblade radiofrequency (DLMR) device has been developed to achieve full-thickness skin rejuvenation by stimulating the papillary and reticular dermis simultaneously. This modality’s dual-level targeting concept need to be validated on human skin, although its clinical efficacy has been demonstrated in a previous study. Materials / method: Human facial skin samples were obtained from thirteen Asian patients who had facelift surgery for ex vivo and in vivo studies. DLMR-treated ex vivo skin samples were analyzed using a digital microscope, thermal imaging, and hematoxylin and eosin (H&E) staining immediately after application. For the in vivo analysis, both treated and untreated samples from symmetrical areas were stained with H&E, Masson's trichrome, and Verhoeff-Van Gieson method. Total collagen content and mRNA expression levels of collagen types I/III and vimentin were also analyzed. Results: The novel DLMR technique successfully induced thermal stimulation in the papillary and reticular dermis. The thickness, stacks, and dermal–epidermal junction (DEJ) convolution of the epidermis treated with DLMR were significantly increased. Collagen bundles in the dermis treated with DLMR exhibited a notable increase in thickness, density, and horizontal alignment. Dermal collagen levels were significantly higher in the morphometric and TCA data, as well as in the qPCR data for dermal matrix proteins. Conclusion: The novel DLMR technique offers precise and independent targeting of both the papillary and reticular dermis, demonstrating it as an effective modality for achieving full-thickness skin rejuvenation.