Glabellar Contraction Patterns and Neurotoxin Efficacy: A Quantitative Assessment.

Area of Science:

• Aesthetic medicine
• Dermatology
• Facial anatomy

Background:

• Standard glabellar frown line treatment uses a fixed 5-point neurotoxin injection technique.
• Patient muscle recruitment patterns vary, influencing treatment efficacy.
• A classification system exists for glabellar patterns (U, V, O, IO, CA), but its impact on outcomes is unquantified.

Purpose of the Study:

• To quantitatively assess the influence of glabellar anatomical patterns on neurotoxin efficacy.
• To evaluate the duration of neurotoxin effects based on distinct glabellar contracture patterns.

Main Methods:

• 142 women received standardized 5-point neurotoxin injections.
• Patients were classified into glabellar patterns (U, V, O, IO, CA) based on muscle recruitment.
• 3D strain analysis (Vectra M3) measured dynamic strain at multiple time points post-injection.

Main Results:

• Significant baseline strain differences were observed among patterns (P=0.029).
• All patterns showed strain reduction by 90 days; U and CA remained improved at 180 days.
• Patterns O and IO had shorter-lived improvements and higher residual strain.

Conclusions:

• Glabellar contracture patterns significantly influence neurotoxin efficacy and duration.
• Patterns O and IO benefit from customized injection protocols targeting additional muscles.
• Tailoring treatments to individual glabellar anatomy can enhance patient outcomes.