INTRODUCTION
OnabotulinumtoxinA (ONA; Botox, Allergan, Irvine, CA) was discovered for cosmetic use in the mid-1980s for which it was FDA approved in April 2002. AbobotulinumtoxinA (ABO; Dysport, Valeant Pharmaceuticals International, Inc, Montreal, Quebec) was FDA approved in April 2009 for therapeutic and esthetic uses. The most recent studies make a comparison between the two formulations; ho...