Is my masseter Botox working?

Thank you for your question. It sounds as though you are responding to Botox appropriately and still have the ability to use your left masseter muscle. Full paralysis of the muscle would not be ideal for chewing and cosmesis. If you feel there has been improvement in jaw slimming on the left still with use of the masseter then you probably had the correct amount of units.

I would wait a total of 6-8 weeks to see the full result of your masseter botox treatment. If at this time you are not satisfied with the results I would go back to your provider to address your concerns

You should still be able to clench your teeth after Botox, Dysport or Xeomin in the masseter muscles. The fact that you can’t clench as much is a good sign. You need the muscle to be relaxed, but still functional so you can chew. It generally takes a few weeks before you’ll notice jaw slimming after Botox. If, after 2 months, you don’t notice a change, please consult your board-certified dermatologist to get a higher dose. 

Botox shouldnt stop you from being able to clench or move your mouth.  It should subtly decrease the size and width of the jaw.  You may need more units.  In korea they start at 30-60 units of botox each side.  I suggest seeing your expert and looking at photos.  Dr. Emer.

Thank you for sharing your question.  Botox should not be administered to such levels that it paralyzes the entire masseter.  This would make it difficult to chew for3+ months.  The goal is to weak enough of the muscle that it weakens and atrophied, slimming the back jawline.  It sounds as if your treatment was appropriate.  Hope this helps.

Dear wr0953,it is hard to tell for sure without an examination. I would suggest you to consult a your injector. Only after a thorough examination you will get more information and recommendations.Daniel Barrett, MD, MHA, MS 
Certified, American Board of Plastic Surgery  
Member, Am. Society of Plastic Surgery

“Less than before” is exactly the effect you want. It sounds like your Botox is working fine. If you weren’t able to clench your jaw at all, then you would have been over-treated. It will take a few weeks before your masseters relax and you see facial slimming. A board-certified dermatologist will be able to help you if you don’t get the results you were expecting.

When injecting the masseter muscle we want to weaken this muscle, not disable it. The muscle will get weaker with time and will eventually shrink but this takes a period of time and does not happen as soon as Botox takes effect. I do a lot of this for tooth grinding and the grinding improves in a couple of weeks but it takes months until muscle really looks different.

WR,
The level of masseter weakness depends on the concentration / number of units of Botox that you received. In general, the goal of neuromodulator weakening of this area is to reduce flare and overall width to the face. Paralyzing the muscle entirely is not recommended as it would affect your overall aesthetic look since the masseter is important in chewing and speaking. Nonetheless, if you have any concerns, communicating with your injector is highly recommended. 
Hope this helps!Hardik Doshi, M.D.

Injecting botox in the masseter does not completely deactivate the muscle.  You should be able to clench your teeth.