Can you hit a nerve while injecting the masseter muscle?

From your description, I think it is unlikely that any nerve was hit during the Botox injection into your masseter muscle.  It is possible the muscle itself was hit and just got a bit of a bruise below the level of the skin.  In this case, some pain on that side would be possible even though a bruise may not be visible on the skin.  I would expect your issue to resolve completely fairly soon.  

Thank you for sharing your excellent question and I am sorry to hear of your symptoms. It sounds as if either a bruise or muscle irritation occurred during your injections and this should improve given additional time.  Hang in there and inform your injector of your discomfort.  They can provide you with additional reassurance. 

It is possible, though rare, that a nerve could be hit during Botox injections. It's best for you to return to your injector for an evaluation. If this is what occurred it's not likely to cause permanent damage.

Although it is always possible to hit a nerve with injection, the most likely reason for your discomfort is a bit of bleeding into the muscle which will completely disappear on its own

Chances are very small that a branch of a nerve was hit but it is possible. The most likely scenario is that you have a small bruise in the muscle and it will continue to hurt until it's resolution. Applying moist, warm compresses will help quite a bit. Good luck for New York City

It is possible that the Botox irritated a nerve or hit a muscle and lead to the pain that you are experiencing.  I would return in a week to your treating physician for examination.  Botox injections in the masseter is a higher injection skill and I would consult an expert in that area.  Best, Dr. Green

Hey there! thanks for the question!
To me your description sounds much more like a deep bruise than a nerve injury. This is always a risk when needles are inserted in to the body but it's not usually serious. The good news is - it sounds like it's already improving!  good luck

The most likely problem is that there is a small hematoma. This should gradually resolve without any long-term side effects. Apply warm compresses and take tylenol or motrin. This should not be a permanent problem.