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Background and aim: Pattern-based approaches for botulinum toxin injection in the glabellar region have been proposed to optimize treatment outcomes according to individual muscular contraction patterns. However, evidence regarding the necessity of modifying injection techniques based on these patterns remains inconsistent. This study compared the efficacy of a standardized 3-point abobotulinumtoxinA (Dysport®) injection technique among different glabellar contraction patterns in an Iranian population.
 

Methods: A total of 224 Iranian patients with moderate-to-severe glabellar lines were included. Patients were classified into five glabellar contraction patterns: U, V, Omega, Inverted V, and Converging Arrow. All participants received 40–60 IU of Dysport using the same 3-point injection technique. Clinical efficacy was assessed 30 days after treatment using the Glabellar Line Severity Scale (GLSS) based on live investigator assessment, independent evaluator assessment, and patient self-assessment. Treatment response was defined as a≥2-point reduction in glabellar line severity during maximum frown.
 

Results: No significant differences were observed among groups regarding age, sex distribution, or onset of treatment response (P>0.05). Patients with the Inverted V pattern received significantly higher toxin doses than those with U and V patterns (P=0.039 and P=0.031, respectively). Response rates based on live assessment, independent assessment, and patient self-assessment showed no statistically significant differences among contraction patterns (P=0.371, P=0.113, and P=0.360, respectively).
 

Conclusion: Glabellar contraction patterns did not significantly affect short-term clinical response to a standardized 3-point Dysport injection technique, suggesting that complex pattern-based injection modifications may not be necessary for satisfactory early outcomes.