Botulinum toxin A in the therapy of mimic facial lines.
In aesthetic medicine, many different methods of skin rejuvenation are available. At the end of the 1980s, the neurotoxin Botulinum toxin A (BT-A) led to a revolution in aesthetic-corrective dermatology for the treatment of mimic facial wrinkles. The toxin is produced by Clostridium botulinum and causes a reversible, selective muscle relaxation that leads to a temporary flattening of the mechanical part of wrinkling without the stigmata of invasive surgery. After two decades of experience in different medical disciplines, there has been remarkable clinical development and progress in research, the identification of new botulinum toxin serotypes, and also innovation in indications and combined modalities. These lead to new and interesting questions. BT-A offers the experienced, critical dermatologist a time-saving, effective, cosmetically satisfactory, non-invasive treatment for mimic facial wrinkles and neck and decollete lines, with only minor side effects. Dermatologists should have a profound anatomical knowledge and should be able to perform all injection techniques to meet the needs of ever more demanding patients and to ensure optimization of patient satisfaction. The following review summarizes the historical development and the mechanism of action of both frequently and rarely used injection techniques with BT-A for the treatment of wrinkles and lines of the upper face, neck and décolleté, and gives an update of different experiences encountered.