BOTOX® as Treatment for Masseter Hypertrophy

BOTOX®treatment was first approved in 1989 to treat twitching eye muscles, known asblepharospasm. During treatment, it was noticed that frown lines near thetreated 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 April2002. Since then BOTOX®treatment has become one of the staples of cosmetic surgery. BOTOX®injections are the most popular cosmetic procedure, numbering approximately 4million injections per year.

ThoughBOTOX® is prepared from a bacterium called botulinum, the product is safe andeffective. The toxin is extracted from the botulinum and is not live orcontagious. Despite rumors to the contrary, there is no way to contract the illnessthrough the injections. BOTOX® acts by blocking the chemical compound used totrigger muscle contraction, thereby reducing those actions where they affectthe skin and cause wrinkles. Recently, BOTOX® has proven effective as treatmentfor masseter hypertrophy as well.

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

MasseterHypertrophy

Themasseter muscle is the main muscle of the jaw and is considered the mostpowerful muscle in the human body. Hypertrophy is an enlargement of the musclecell and is a normal result of exercise. Excessive hypertrophy of the massetermuscle may be caused by bruxism (grinding teeth), TMJ, or misaligned jaws. Thecondition may cause discomfort or simply present an asymmetrical appearance.Historically, masseter hypertrophy that did not correct itself was treated withsurgery.

Anew, more conservative approach is the use of BOTOX® as treatment for masseterhypertrophy. BOTOX blocks the release of acetylcholine from firing the synapticresponse that contracts the muscle. The treatment is not yet approved by theFDA but is frequently performed off-label. The treated muscles eventuallyatrophy and weaken within two to 20 days. Eventually, new axon endings formrestoring the neuromuscular transmission.

Asianpatients in particular seek correction of masseter hypertrophy for aestheticreasons. Surgical reduction of the masseter muscle is a common procedure amongpatients of Asian descent who want to give themselves a more delicate jaw lineand reduce their mandibular angle. Several studies of BOTOX® as treatment formasseter hypertrophy show good results, with high satisfaction rates. Thisprocedure is a simple alternative to surgery providing predictable results.