Treating the Forehead Lines with Combination of Forehead and Glabellar Botulinum Toxin Among Japanese Patients

Background: In Japanese clinical practice, two approaches using botulinum toxin A (BTA) are used to improve wrinkles in upper and lower forehead areas without any complications, namely upper forehead subcutaneous (sc)/lower forehead intradermal (id) injections and upper forehead sc/glabellar intramuscular (im) injections. Aim: To investigate the therapeutic effects of combining upper forehead sc and glabellar im BTA injections on forehead wrinkles. Methods: Twenty-two participants were assigned to two groups: group A received upper forehead sc/lower forehead id injections, while group B received upper forehead sc/glabellar im injections. Pain intensity, effects on forehead and glabellar wrinkle severity, eyebrow height/balance, side effect questionnaires, and patient satisfaction were assessed. Results: Forehead wrinkle severity was significantly reduced at week 4 in both groups. During the follow-up period, the severity in group B was consistently lower than group A. Glabellar wrinkles significantly improved only in group B. No abnormalities in eyebrow height or balance and no significant differences in pain intensity were observed. No serious side effects were reported, and patient satisfaction was consistently higher in group B than group A. Conclusions: The results suggest that upper forehead sc/glabellar im injections are more useful in treating forehead wrinkles than upper forehead sc/lower forehead id injections.