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Square Jaw (Overactive Masseter)
Causes, Symptoms and Treatment 

The square jaw associated with a large masseter muscle gives a very masculine appearance. Female patients are seeking a softer more feminized shape to their face which adds to a more graceful appearance. 


Some causes of square jaw due to enlarged masseter muscle:

-Excessive or constant chewing: some people develop the habit of constantly chewing or excessively chewing hard food items or chewing gum. This can cause the jaw muscle to expand in size giving it a squarer look.

-Bruxism or teeth clenching. Some people have a habit of clenching their jaw and grinding their jaw even in their sleep. This leads towards expansion of the masseter muscle or muscle hypertrophy and hence square jaw.

-Ethnicity: Most of the men and women of Asian descend have square jaws which add to the masculine appearance. 

Botulinum toxin injections work by weakening the masseter jaw muscle which results in a softer jaw angle. Toxin jaw reduction treatment inhibits the action of the masseter jaw muscle which eventually leads to atrophy (reduction in size due to non use) of the muscle. The softening of the masseter jaw muscle is noticed by patients after two weeks of the treatment with continuous slimming of the jaw for another few months. 

Treatment involves toxin injections into the jaw line on both sides of the jaw. The procedure takes around 20 minutes. There are no severe side effects of treatment but minor side effects in extreme cases include swelling, bruising, mild pain in the jaw muscles especially during chewing, These side effects are only temporary and fade away in a few days.

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