Doctor's Answers (2)
1. Diffuses to surrounding muscles
2. Is placed in the correct muscle, but the dosage is too high
For masseter reduction with botox:
1. If the botox diffuses to the muscle in front, called the risorus, your smile will be affected and becomes asymmetrical. This gives rise to the feeling of “stiffness” in the face.
2. If the dosage is too high, the masseter muscle can become over-shrunk, and there will be a hollowness at the sides of your face.
Botox (short for Botulinium Toxin A) usually lasts 5-6 months, so in case any side effects are encountered, it goes away after 5-6 months.
Hope this helps!
For masseters, as Dr Wong has pointed out, Botox leads to a reduction/atrophy of the jaw muscle. However, the results can vary depending on dosage used vs the number/location of botox injections.
Only when it diffuses into the muscles will you have a stiffness of the face due to Risorius and other muscle involvement.
It will last between 6-12 months depending on lifestyle behaviour and the duration increases over the sessions done.