Facial aesthetics: Is Botulinum toxin treatment effective and safe? A systematic review of randomised controlled trials

BACKGROUND: The use of botulinum toxin type A (BTA) in facial aesthetics for the treatment of wrinkles has recently become more popular as an alternative to surgical techniques. However, its true efficacy and potential adverse effects are still unclear. OBJECTIVES: The primary objective of this study was to review the efficacy of BTA in facial aesthetics. A secondary objective was to determine whether there are any adverse effects associated with the procedure of using BTA in facial aesthetics. SEARCH STRATEGY: We conducted literature searches on Medline (1977 to January 2009), Cochrane Controlled Trials Register (CENTRAL), EMBASE (1977 to January 2009) and CINAHL (1977 to January 2009). The search strategy also included reference lists of located articles and hand searching for randomised controlled trials (RCTs). We contacted authors of studies for further information where required. SELECTION CRITERIA: Randomised studies comparing BTA with placebo in facial aesthetics in a double-blind and crossover or parallel group design. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. The area of face injected, assessment methods, outcome measures, duration of action of BTA and associated adverse effects were reviewed. RESULTS AND DISCUSSION: A total of eleven RCTs involving 1,603 subjects were found, of which 1,203 were enrolled for treatment with BTA. The 11 trials were not directly comparable to each other due to differences in the areas of the face injected with BTA, length of study period, concentration of BTA used and outcome measures. The studies showed similar trends. The use of BTA showed improvements in facial wrinkles over placebo, with a peak effect reported at around one month and the effects lasting between 4-6 months. No studies reported any severe adverse effects. The incidence of blepharoptosis in glabellar lines treated with BTA was reported to be between 0-5.4%, and may be related to the technique of injection into the muscles. The incidence of other side-effects such as headache, pain at injection site and mild bruising was similar in both the BTA and placebo groups. AUTHORS' CONCLUSIONS: The use of BTA in facial aesthetics is more effective than placebo. The incidence of adverse effects associated with BTA is similar to placebo, with the exception of blepharoptosis which is reported to be 0-5.4% after treatment of glabellar lines with BTA.