Botulinum toxin type A for preventing and treating cleft lip scarring—A systematic review and meta‐analysis

Cleft lip and/or palate (CL/P) are congenital cleft facial deformities that are abnormal developments caused by errors in the fusion process of the embryo's face. Surgery is an important treatment, but postoperative scars will still cause psychological shadows to patients. This study aimed to systematically evaluate the efficacy of Botulinum toxin type A (BTXA) in preventing and treating postoperative CL/P scars and improving scar quality.A systematic review was performed by searching PubMed, EMBASE, the Cochrane Library, and Web of Science for relevant trials. All relevant trials were performed before June 30, 2021. The data were entered into Revman 5.3 software, and a meta-analysis was conducted by using the random-effects model or fixed-effects model.Four randomized controlled trials involving 161 cases were included. Through quantitative analysis, BTXA showed significant differences in preventing and treating postoperative CL/P scars in terms of scar width (MD: -0.20; [95% CI, -0.30, -0.10], p < 0.0001) and the Visual Analog Scale (VAS) (MD: 1.30; [95% CI, 1.06, 1.55], p < 0.0001), although no significant difference was noted on the Vancouver Scar Scale (VSS) (MD: -0.75; [95% CI, -1.68, 0.19], p = 0.12) between the two groups.In preventing and treating postoperative CL/P scar hypertrophy, we found that BTXA injection can show better results. There was no statistically significant difference between the results after omitting Navarro's study or Chang's study because of the time of injection-before/during surgery or adult CL/P scars.