How would I know if/when I need more Botox in my masseters?

 Botox in your masseter muscles should not affect chewing, so don't try to use that as a sign for whether you need another treatment or not. Botox in the jaw can last up to six months or more, so I would let that serve as a guideline. Every person is different, and so you will have to pay attention to how your face looks. You may find the effects wear off after about 4 months, or they may last til almost a year. A safe bet is to re-treat biannually. You should be able to maintain good results without spending too much time in the dermatologist's office. Consulting your board-certified dermatologist will allow the two of you to develop a schedule for your Botox maintenance.

I would suggest that you schedule a maintenance visit in 6 months. This is when most patients find that they need a touch up. Hope this helps. 

Botox and other neurotoxins are used on the masseters to slim the face.  Treatment should not affect  chewing.  For the initial treatment, you may require more than 20 units per side to see the desired results.  However, once the desired results are seen you will typically require less for maintenance and less frequently (every 6 months) than for other areas on the face.  Consult with a board-certified and experienced cosmetic physician. 

Most patients do not see a bit problem after injection. Your goal is to see a change in the thickness of the muscle. This may take several treatments. Good luck.

Thank you for your question.  The masseters are very strong muscles, and most patients do not notice any difference in their bite strength even after much higher doses of Botox.  The muscle shrinkage after a Botox injection typically lasts anywhere from 6-12 months, and I usually recommend that patients return for treatment every 6 months to prevent regrowth of the muscles.  I hope this helps!     

The timing of the injection of Botox for the masseter depends only on the appearance of the face so when you notice that it is not so contoured as before then you may consider another injection. the chewing is not greatly affected so don't depend on that

most people can't feel the difference in the bite strength after having their masseter muscles treated with botox. The reason for that is that you have another very powerful chewing muscle and that's called the temporalis muscle. You should judge the need for additional Botox by the appearance of your face more than anything else. Good luck from New York City