Efficacy and Safety of Microwave Energy–Based Device for Facial Rejuvenation: A Retrospective Comparative Study with High-Intensity Focused Ultrasound

Abstract Background Facial aging is characterized by soft tissue atrophy, subcutaneous fat redistribution, and dermal laxity, most pronounced in the lower face and submental region. High-intensity focused ultrasound (HIFU) is the benchmark non-invasive lifting modality, whereas microwave-energy-based devices (MEBD) have recently emerged, targeting adipose tissue and dermis. While MEBD has been validated in body contouring, evidence for facial efficacy and safety remains limited. Objectives This study aimed to compare the efficacy and safety of MEBD and HIFU for facial rejuvenation in an East Asian population, emphasizing temporal improvement patterns, tolerability, and adverse events. Methods We retrospectively analyzed 171 patients (MEBD: n = 89; HIFU: n = 82) treated at a single institution. MEBD used 7 mm and 3 mm handpieces for subcutaneous lipolysis and dermal tightening, guided by fat compartment mapping. HIFU applied 600 shots at 3.0 mm and 4.5 mm depths targeting dermis and SMAS. Outcomes included blinded evaluator GAIS, Cutometer elasticity, FACE-Q satisfaction, pain, and adverse events, assessed at baseline, 1 month, and 3 months. Results MEBD showed greater early improvements in GAIS, Cutometer parameters (R2, R5), and FACE-Q scores at 1 month, with lower pain (2.3 vs. 4.7, p < 0.001) and fewer adverse events. By 3 months, HIFU surpassed MEBD in sustained GAIS, FACE-Q, and elasticity gains. Both modalities were safe, with only mild, transient effects. Conclusions MEBD demonstrated rapid onset, superior tolerability, and lower complication rates, while HIFU provided stronger long-term lifting and elasticity improvements. These findings support complementary clinical roles and a compartment-based rationale for facial MEBD.