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What is Botox?
Botulinum toxin Type A, or Botox®, is a highly purified neurotoxin derived from the anaerobic bacterium Clostridium botulinum, found in soil and water worldwide. In minute quantities it produces a localized weakening of the muscle into which it has been injected. It has been used since 1980 for the treatment of some forms of strabismus to aid in alignment of the eyes. It has been most commonly used to control debilitating blinking disorders such as benign essential blepharospasm and hemifacial spasm. It was in its use for eyelid spasms that the associated beneficial effects of decreasing facial wrinkling were first noted. This experience led to an interest in using the toxin for unwanted hyperkinetic facial lines such as brow furrows, excessive forehead folds, and crow’s feet. Botox® was FDA approved for the cosmetic treatment of glabellar folds in 2002 and appears to now have a positive role to play in the management of cosmetic facial rejuvenation.
How does it work?
Botox® works by blocking the release of a neurotransmitter at the junction between the nerve and muscle in a very specific manner allowing it to be effective in very small concentrations. This causes a temporary weakness of the underlying facial muscle resulting in a relaxation and flattening of the facial skin and an improved cosmetic appearance. The effect occurs within 24 to 48 hours, stabilizes after 1 to 2 weeks and lasts 3 to 6 months, occasionally longer. As muscle tone returns to normal, injections can be repeated every 3 to 6 months, indefinitely. No long term evidence of permanent degeneration or atrophy has been found on muscle biopsies after repetitive injections. Patients receiving very high doses of toxin may occasionally develop antibodies to the toxin which may render the patient unresponsive to further treatment. This is not seen at the doses used for treatment of facial wrinkles.
Are there side effects?
Botox® is a very safe agent for cosmetic purposes mainly because the therapeutic dose is low and the effects are localized and reversible. Therefore, side effects associated with the toxin are reversible within a relatively short period of time. If the toxin seeps into surrounding muscle tissue it may cause temporary weakness at these sites as well. This may result in eyelid droop (<2%) which typically lasts only 2 to 4 weeks. Occasionally, bruising at injection sites, headache, or numbness in a small area of the forehead may occur which resolves after 2 to 3 hours.
There are few contraindications to the use of Botox®. These include known hypersensitivity to ingredients in the commercial formulation (human albumin and saline), muscular or neurological diseases, and in pregnant or lactating women.
What can be treated?
Along with facial treatments (detailed below), Botox Cosmetic also effectively treats migraines and perspiration reduction.
Glabellar Frown Lines: These vertical mid-forehead wrinkles can become very deep and prominent and give unintended social cues, such as anger, fear, or worry. The effect of these lines can be so annoying that many individuals seek cosmetic treatment.
The muscles controlling frown do not serve any other function; therefore, paralysis here will not result in any untoward side effects. Some individuals frown inappropriately or subconsciously, often while concentrating or even during sleep. In these individuals, paralysis of the glabellar central brow musculature eliminates the frown, allows a more flattened expression and, in addition, relieves frontal tension. Significant weakening of the area allows the unopposed action of the central frontalis, producing a more satisfactory “open-eyed” look. The Food and Drug Administration approved Botox® for this indication in 2002.
Crow’s Feet: “Crow’s feet” are wrinkles extending laterally in the area of the temple and are usually a sign of aging. These are produced by the contraction of muscles associated with facial expression (orbicularis oculi). By relaxing the relevant muscles, treatment of “crow’s feet” is successful even when the skin is severely photoaged. Effects last an average of 3 to 4 months with retreatment every 4 to 6 months. Botox® significantly reduces but does not eradicate these wrinkles.
Horizontal Forehead Lines: Deep forehead creases can be treated and softening of the lines can be accomplished by judicious weakening of the frontalis muscle. Treatment in this area requires a more cautious approach in order to prevent undesirable effects such as an unwanted lowering of the brow and a somewhat angry appearance. Patients should be aware of this possibility and a careful approach to injection sites and dosage is necessary. Overall, however, the effect can be most satisfying creating a smoother, less stressed appearance to the forehead. Botox® is a very safe agent for cosmetic purposes mainly because the therapeutic dose is low and the effects are localized and reversible. Therefore, side effects associated with the toxin are reversible within a relatively short period of time. If the toxin seeps into surrounding muscle tissue it may cause temporary weakness at these sites as well. This may result in eyelid droop (<2%) which typically lasts only 2 to 4 weeks. Occasionally, bruising at injection sites, headache, or numbness in a small area of the forehead may occur which resolves after 2 to 3 hours.
There are few contraindications to the use of Botox®. These include known hypersensitivity to ingredients in the commercial formulation (human albumin and saline), muscular or neurological diseases, and in pregnant or lactating women.
Who can perform Botox treatments?
Botox® therapy should only be performed under the direction of a physician trained and experienced in its use. Ophthalmologists, because of their intimate knowledge of the muscle anatomy around the eye, are uniquely qualified to treat these areas and handle any potential side effects.
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