Cosmetic denervation of the muscles of facial expression with botulinum toxin - A dose-response study

BACKGROUND. Botulinum toxin has been used for facial hemispasm, strabismus, and blepharospasm. Recently it has been advocated to treat the flown lines. We have extended this program to treatment of other muscles of facial expression. METHODS. Botulinum toxin is injected into the muscles of facial expression in two or three sessions to produce a temporary loss of muscle tone. A standard method of cooling, injection, and compression was developed to minimize pain and bruising. OBJECTIVE. To complete a dose-response study to document the optimum timing and amount of toxin needed for each muscle group. RESULTS. Two to five Botulinum toxin units per muscle was as adequate as higher doses. Toxin that was reconstituted 30 days earlier produced the same loss of muscle tone as freshly mixed toxin. With two or three injection sessions loss of muscle tone lasted for up to 1 year. CONCLUSION. Botulinum toxin is highly effective as an adjuvant therapy for facial rejuvenation. This minor surgical procedure can temporarily reduce the lines on the upper face and produce a pleasing effect. With proper dosing and dilution this rejuvenation program becomes cost effective.