The use of botulinum toxin A to reverse paralysis of the lower lip
Reviewed by Bilal Gani Taib

The aim of this retrospective case series was to examine the role of botulinum toxin A in paediatric patients with paralysis of the lower lip. Depressor or elevator muscles of the lip (unaffected side) were injected with varying doses of the toxin dependant on the muscle (range 5.0-25.0 units). For focal synkinesis injections were marked over the most prominent areas. Lip deviation before and after the intervention was measured using facial analysis software. Eighteen patients were identified; focal lip asymmetry (n = 11), extensive hemifacial symmetry (n = 5) and focal synkinesis (n =2). The mean dynamic deviation before the intervention was 3.5 mm and after was 1.5 mm. This was found to be statistically significant at p = 0.04. The time period between the botulinum injections was four months and no complications were recorded during the two-year follow-up. In conclusion this study shows that botulinum toxin injection represents a viable adjunct in the reestablishment of facial symmetry.

The role of botulinum toxin A in the establishment of symmetry in paediatric paralysis of the lower lip.
Haykal S, Arad E, Bagher S, Lai C, Hohman M, Hadlock T, Zuker R, Borschel G.
JAMA FACIAL PLASTIC SURGERY
2015;17(3):174-8.