A prospective and randomized study comparing ultrasound‐guided real time injection to conventional blind injection of botulinum neurotoxin for glabellar wrinkles.

Background: Botulinum neurotoxin injections are the most frequently performed cosmetic procedures, but conventional blind injection for glabellar wrinkles remains to have some limitations. Aims: We intend to directly inject botulinum neurotoxin into the glabella complex guided by real time ultrasound. We aim to propose a more efficient and safer botulinum neurotoxin injection strategy for glabellar wrinkles. Methods: A total of 40 subjects with moderate to severe glabellar lines were enrolled in this study to receive botulinum neurotoxin injection, either through ultrasound‐guided real time injection or conventional blind injection. Facial Wrinkle Scale (ranging from 0 = none to 3 = severe) and inter‐brow distance (from 3D scanned face images) were used to evaluate the glabellar wrinkles improvement. Paired t test and two‐sample t test were performed to analyze the within‐group and between‐group differences. Results: The wrinkle score reduction was significant (p < 0.0001) immediately after the injection in ultrasound‐guided injection group, but not in blind injection group (p = 0.163). Ultrasound‐guided injection also showed a higher performance of wrinkle score reduction and more effective inter‐brow distance increase over blind injection at Day 0 (p < 0.0001), Day 1 (p < 0.0001), Day 21 (p < 0.01) and Day 35 (p < 0.01) after initial treatment. Conclusions: The results of the study confirmed that botulinum neurotoxin injection for glabellar wrinkles under ultrasound guidance achieves quicker onset of action and better final outcomes compared to conventional blind injection. [ABSTRACT FROM AUTHOR]