Methodological Heterogeneity and Reporting Gaps in Clinical Studies of High-Intensity Focused Ultrasound for Facial and Neck Rejuvenation: A Scoping Review

This scoping review aimed to map the clinical evidence on high-intensity focused ultrasound (HIFU) and microfocused ultrasound (MFU) for facial and neck rejuvenation, with particular emphasis on quantitative measures of linear tissue displacement or elevation. A total of 12 clinical studies were included, comprising 8 prospective uncontrolled, 2 prospective controlled, and 2 retrospective studies. Ulthera and the Ultraformer family were the most frequently used platforms, each appearing in 4/12 studies (33.3%). The forehead/eyebrow region was the most frequently evaluated anatomical area, with quantitative displacement or elevation outcomes reported in 9/12 studies (75%), whereas the neck was assessed in only 1 study. Treatment parameters varied considerably, and follow-up ranged from immediately post-treatment to 1 year. Mean eyebrow elevation ranged from 0.40 to 2.16 mm, while maximum eyebrow elevation ranged from 1.06 to 2.35 mm. Participant age ranged from 20 to 81 years, and female participants substantially outnumbered males. BMI and ethnicity were reported in 4 and 7 studies, respectively. Overall, heterogeneity in treatment protocols, measurement methods, and follow-up schedules limited direct comparisons between studies. Further standardized research is needed to characterize the extent and long-term maintenance of HIFU/MFU-induced objective tissue elevation.