title: Characterizing the lateral slope of the aging female eyebrow.
abstract: BACKGROUND
  Ideal eyebrow aesthetics give a framework for brow rejuvenation and surgical procedures do not always provide satisfying results. Previous studies have shown elevation of the medial brow with aging; however, they failed to characterize overall shape changes.
  
  
  OBJECTIVE
  To characterize changes in eyebrow slope with increasing age to better direct brow rejuvenation.
  
  
  METHODS
  From standardized anteroposterior facial photographs of 100 women 20 to 80 years of age, eyebrow height was measured at the medial limbus and arch apex from a mid-pupillary horizontal. The slope of the eyebrow was calculated. Using group analysis, mean height and slope were compared using the Mann-Whitney U test. Regression analysis was used to determine the relationship between slope and age.
  
  
  RESULTS
  Mean slope significantly decreased from 20 to 29 years of age to 40 to 49 years of age (0.22 versus 0.12; P=0.03), and then increased between 40 and 49 years of age and ≥60 years of age (0.12 versus 0.21; P=0.05). Medial height did not change significantly, and arch apex significantly decreased between 20 and 29 years of age and 40 and 49 years of age. Regression analysis showed a quadratic relationship between age and slope, with the decrease in slope until the fifth decade of life being directly related to increasing age. After this, age was not a significant contributor to slope changes.
  
  
  CONCLUSIONS
  With increasing age, the slope of the eyebrow decreases until the fifth decade dependent on age. After the fifth decade, age no longer plays a significant role. Therefore, choice of brow lift technique should be carefully selected.
authors.affiliation: Division of Plastic Surgery, Department of Surgery, London Health Sciences Centre, Schulich School of Medicine and Dentistry, Western University, London, Ontario.
authors.forename: Tanya L
authors.initials: TL
authors.lastname: Delyzer
authors.affiliation: Division of Plastic Surgery, Department of Surgery, London Health Sciences Centre, Schulich School of Medicine and Dentistry, Western University, London, Ontario.
authors.forename: Arjang
authors.initials: A
authors.lastname: Yazdani
keywords: Aging eyebrow; Brow lift; Eyebrow shape; Eyebrow slope