Background: Patterns of crow's feet lines (CFLs) vary among individuals.
Objective: To characterize distribution and predictors of CFL patterns.
Methods: Patterns of CFLs (full fan, lower fan, central fan, and upper fan) were evaluated at maximum smile and at rest from photographs of subjects with moderate-to-severe CFLs. Relationships between CFL pattern and severity, age, gender, and subject-reported outcomes were explored.
Results: Evaluations of 2,699 photographs from 1,392 subjects were conducted; 1,389 and 1,310 had evaluable CFL patterns at maximum smile and at rest, respectively. Lower-fan, central-fan, and full-fan patterns were identified in 28.4% to 34.7% at maximum smile and 27.7% to 33.9% at rest; upper fan was found in ∼5%. The pattern distribution of CFLs demonstrated a relationship to baseline CFL severity, age, and gender; full-fan and lower-fan patterns were more common in severe versus moderate CFL at maximum smile; full fan increased with age. Lower fan was more common in males. Subjects with full fan at maximum smile were most dissatisfied with their appearance and perceived themselves to look older versus other patterns.
Conclusion: Baseline CFL severity, age, and gender may predict fan pattern. Patterns may progress with age from central to lower fan or full fan. Pattern heterogeneity of CFLs suggests that tailored treatment may be warranted.