Botulinum toxin to improve results in cleft lip repair: a double-blinded, randomized, vehicle-controlled clinical trial

Abstract

Background: Most patients with facial scarring would value even a slight improvement in scar quality. Botulinum toxin A is widely used to alleviate facial dynamic rhytides but is also believed to improve scar quality by reducing wound tension during healing. The main objective was to assess the effect of Botulinum toxin on scars resultant from standardized upper lip wounds.

Methods: In this double-blinded, randomized, vehicle-controlled, prospective clinical trial, 60 consecutive consenting adults undergoing cleft lip scar revision (CLSR) surgery between July 2010 and March 2012 were randomized to receive botulinum toxin A (n = 30) or vehicle (normal saline; n = 30) injections into the subjacent orbicularis oris muscle immediately after wound closure. Scars were independently assessed at 6-months follow-up in blinded fashion using: Vancouver Scar Scale (VSS), Visual Analogue Scale (VAS) and photographic plus ultrasound measurements of scar widths.

Results: 58 patients completed the trial. All scar assessment modalities revealed statistically significantly better scars in the experimental than the vehicle-control group.

Conclusion: Quality of surgical upper lip scars, which are oriented perpendicular to the direction of pull of the underlying orbicularis oris muscle, is significantly improved by its temporary paralysis during wound healing.

Trial registration: ClinicalTrials.gov NCT01429402.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1. Contractions of the orbicularis oris muscle are believed to inflict repeating micro-trauma to the healing wound, causing an initially narrow scar to slowly widen.

Lower right: A patient in the control group exhibiting an elevated scar after suture removal.

Figure 2. Consort statement flow chart.

Figure 3. Six injections of encoded vial content were administered to the orbicularis oris muscle 5 mm either side of the wound below the nasal base and above the vermillion border.

Figure 4. Photographic measurement of the scar: the First Point was 1 mm above the white roll and the Second Point was 1 mm below the turning incision line, close to the nasal sill.

Figure 5. The width of upper lip scar was measured by ultrasound, as indicated by the two green crosses.

Figure 6. The upper row illustrates scarring of three patients in the experimental group (botulinum toxin) and lower row illustrates the scars of three vehicle-control group patients at six months' follow-up.