BOTOX® treatment was first approved in 1989 to treat twitching eye muscles, known as blepharospasm. During treatment, it was noticed that frown lines near the treated areas were smoothed over, providing a cosmetically appealing effect. Patients no longer showed the deep creases or folds of tissue near the eyes. These observations lead to clinical trials and subsequent FDA approval as a cosmetic application in April 2002. Since then BOTOX® treatment has become one of the staples of cosmetic surgery. BOTOX® injections are the most popular cosmetic procedure, numbering approximately 4 million injections per year.

Though BOTOX® is prepared from a bacterium called botulinum, the product is safe and effective. The toxin is extracted from the botulinum and is not live or contagious. Despite rumors to the contrary, there is no way to contract the illness through the injections. BOTOX® acts by blocking the chemical compound used to trigger muscle contraction, thereby reducing those actions where they affect the skin and cause wrinkles. Recently, BOTOX® has proven effective as treatment for masseter hypertrophy as well.

BOTOX® is not an injectable filler , but a neurotransmission blocker used to deaden muscles that cause wrinkles. It is made of a sterile form of botulinum toxin that is typically injected under the skin, which deadens the nerve endings that cause wrinkles. The toxin basically acts to paralyze the muscle to prevent the actions that cause wrinkles. Much like the transfer from blepharospasm to cosmetic procedure, BOTOX® is now used in a similar manner to deaden the masseter muscle, reducing the size of the muscle over time.

Masseter Hypertrophy

The masseter muscle is the main muscle of the jaw and is considered the most powerful muscle in the human body. Hypertrophy is an enlargement of the muscle cell and is a normal result of exercise. Excessive hypertrophy of the masseter muscle may be caused by bruxism (grinding teeth), TMJ, or misaligned jaws. The condition may cause discomfort or simply present an asymmetrical appearance. Historically, masseter hypertrophy that did not correct itself was treated with surgery.

A new, more conservative approach is the use of BOTOX® as treatment for masseter hypertrophy. BOTOX blocks the release of acetylcholine from firing the synaptic response that contracts the muscle. The treatment is not yet approved by the FDA but is frequently performed off-label. The treated muscles eventually atrophy and weaken within two to 20 days. Eventually, new axon endings form restoring the neuromuscular transmission.

Asian patients in particular seek correction of masseter hypertrophy for aesthetic reasons. Surgical reduction of the masseter muscle is a common procedure among patients of Asian descent who want to give themselves a more delicate jaw line and reduce their mandibular angle. Several studies of BOTOX® as treatment for masseter hypertrophy show good results, with high satisfaction rates. This procedure is a simple alternative to surgery providing predictable results.