Introduction
Successful treatment with botulinum toxin (BTX) requires a
thorough understanding of facial anatomy, proper injection
technique and dosing. Treatment of selected facial muscles with BTX
has become an integral component in the rejuvenation armamentarium.
One of the first clinical applications of BTX was in the treatment
of blepharospasm (1, 2). The subsequent use of BTX in the cosmetic
arena was sparked by Drs. Jean and Alastair Carruthers' observation
in 1987 that glabellar frown line appearance was improved in
patients treated with BTX for blepharospasm. Further study of the
cosmetic applications of BTX resulted in a landmark paper
describing its use in the treatment of glabellar lines (3). Since
that time, there has been a meteoric rise in the use of BTX, and it
is currently the most commonly performed nonsurgical aesthetic
procedure (4).