chapter  21
Aging Face
ByBradford Terry, Laura T. Hetzler
Pages 22

INTRODUCTION Injection of botulinum toxin has become the most frequent aesthetic procedure performed in the United States. It is versatile and outstandingly safe when used properly by experienced practitioners. Botulinum toxin products are derived from two serotypes of neurotoxins produced by Clostridium botulinum. Botulinum toxin temporarily improves dynamic rhytids caused by muscle contraction.