Background: Upper lip wounds that lie perpendicular to the relaxed skin tension lines are subjected to repetitive dynamic tension caused by the orbicularis oris muscle and are susceptible to unsatisfactory scarring.
Methods: In this double-blind, randomized, vehicle-controlled, prospective trial, 60 consecutive patients with unilateral cleft lip undergoing primary cheiloplasties between August of 2011 and June of 2012 were randomized to receive botulinum toxin type A or vehicle injections into the subjacent orbicularis oris muscle immediately after wound closure. Scars were assessed after 6 months using the Vancouver Scar Scale, photographic visual analogue scale, and photographic scar width measurements.
Results: Fifty-nine patients completed the trial. Measurements of scar widths at two defined points revealed significantly better visual analogue scale scores and narrower scars in the experimental group. However, Vancouver Scar Scale assessments were similar between groups.
Conclusions: Botulinum toxin injections into the subjacent orbicularis oris muscle produced better appearing and narrower cheiloplasty scars, but provided no additional benefits in terms of scar pigmentation, vascularity, pliability, or height.
CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.