The Efficacy and Safety of Botulinum Toxin Type A Injections in Improving Facial Scars: A Systematic Review and Meta-Analysis.

[BACKGROUND] Botulinum toxin type A (BTA) has a wide range of clinical applications, and its use in improving aesthetics is one of them. The aim of this study was to better assess the efficacy and safety of BTA in patients with facial scars.

[SUMMARY] We extracted the data of the visual analog scale (VAS) score, Vancouver scar scale (VSS) score, scar width, observer scar assessment scale (OSAS), patient scar assessment scale (PSAS), and/or drug-related adverse events. Five studies provided the data of VAS score, and the results showed that the VAS score in the BTA group was significantly higher than that in the control group. Three randomized controlled trials (RCTs) reported the VSS score. A statistically significant difference exists between the BTA group and the control group. Three RCTs reported the scar width after BTA treatment. A more favorable change was found in the BTA group with scar width even without statistical significance. Data about the OSAS and PSAS scores were available in two trials. There was no significant difference in OSAS and PSAS scores between the BTA group and the control group. Only three studies recorded three slight adverse events. There were no reports of severe complications. In conclusions, this study demonstrated that BTA has the potential to improve facial scars with an acceptable safety profile.