The most common uses for Botox is smoothing of the facial wrinkles of the forehead, between the eyes (glabellar region) and around the corners of the eyes (crow’s feet). These are the most common cosmetic uses that have put Botox on the esthetic map.
It is injected into the facial muscles and, within a few hours, it attaches itself to the nerve endings of the motor muscles, thereby affecting the nerve transmission to these muscles. It takes anywhere from two to ten days to block the nerve transmitters which innervate the muscles where it was injected. There is no loss of sensory feeling at all during the time that botulinum toxin A is effective. Once these motor nerve endings are interrupted, the muscles cannot contract. When the muscle does not contract, the dynamic motion that causes wrinkles in the skin will then cease. The only reason there are wrinkles in the skin in the first place is because the muscle is moving underneath it, thereby these are called dynamic wrinkles. Approximately three to ten days after treatment, the skin above these motor muscles becomes nice and smooth. The effects of Botox lasts approximately three to four months depending on various factors including the amount of botulinum toxin A injected, metabolic activity of the patient and lifestyle choices, which may cause the Botox treatment not to last as long. When the patient sees the wrinkles reappear, the patient needs retreatment.