Two-plane injection of botulinum exotoxin A in glabellar frown lines

Botulinum exotoxin A has been used for the treatment of glabellar frown lines. Despite this fact, the effect of the toxin is sometimes either partial or lost in a short time. The muscles responsible for frowning, the corrugator supercilii and depressor supercilii muscles, are attached to the periosteum in the glabellar region under the frontalis muscle deep in the medial aspect. The muscles then course laterally and superficially to insert in the skin superior to the eyebrows. Thus, to get a long-lasting and full effect, the exotoxin has been applied deeply in the medial aspect and superficially in the lateral aspect of the glabellar region. It is concluded that botulinum exotoxin is more effective when it is applied in two planes superficially and deep so that the anatomic course of the corrugator supercilii and the depressor supercilii muscles are followed.