Eyebrow Height Changes with Aging: A Systematic Review and Meta-analysis

Background: The eyebrows play an important role in emotional facial expressions, nonverbal communication, and facial esthetics. A comprehensive understanding of the mechanisms underlying eyebrow aging is vital in allowing plastic surgeons to appropriately address these age-related changes and to recreate an aesthetically desirable outcome for patients seeking brow rejuvenation. The aim of this study is to summarize the current literature on eyebrow height changes with aging. Methods: A comprehensive search was conducted across several databases to identify all published studies that reported changes of eyebrow position or height with aging, from 1946 to January 2019. Studies that reported eyebrow position at the level of medial canthus, mid-pupil, and lateral canthus were included in a meta-analysis. Results: A total of 346 articles were initially identified, of which 19 met our inclusion criteria. Of 3,634 patients who were identified, 2,237 (64%) were females and 1,274 (36%) were males. Eyebrow height showed significant increase with aging at the level of medial canthus (mean difference 1.4 mm; 95% CI: 0.22-2.59; P = 0.02), and the level of mid-pupil (mean difference 1.17 mm; 95% CI: 0.54-1.8; P = 0.0002). However, no significant difference was found at the level of lateral canthus (mean difference 0.19 mm; 95% CI: -0.87 to 1.25; P = 0.72). Conclusions: Based on the reviewed literature to date, the medial eyebrow height increases with age, whereas it remains stable at the level of the lateral canthus. These results should be considered when considering eyebrow rejuvenation.