Botulinum Toxin to Improve Scar Quality in Cleft Lip Repair: A Systematic Review

Cleft lip repair (CLR) can be complicated by hypertrophic scar or keloid. Botulinum toxin type A (BTA) may improve postoperative scarring by reducing muscle tension and cytokine activity at the scar site. This systematic review analyzes the available evidence regarding the effect of BTA on scar quality after CLR.The search was conducted in 6 different databases in accordance with PRISMA guidelines (PubMed, Scielo, Embase, Scopus, Web of Science, and Cochrane) using "botulinum toxin" and "cleft lip" as keywords.Academic hospital.Exclusive to patients who underwent CLR and BTA injection.Mean visual analog scores (VAS), mean Vancouver scar scale (VSS), scar width, and BTA or CLR-related complications.Five studies for a total of 216 patients met inclusion criteria. Four studies reported on primary CLR during infancy while 1 study recruited older patients seeking revision. All patients had BTA (range: 1-2 units/kg) injected in the orbicularis oris muscle. One study documented BTA injections in additional perioral muscles. All 4 studies that measured scar width and had a saline control arm found a significant decrease in width with BTA injection. Improvement of VAS and VSS with BTA was reported in 3 of 5 studies and 2 of 5 studies, respectively. There were no reports of complications associated with BTA or CLR.The existing studies support the use of BTA injection to improve scar quality following CLR with low concern for complication. Further investigations with a greater number of patients are necessary.