Are Numbing shots bad for you?

So I have had a lot of work done on my teeth through out my life and lately I have had a lot done on one specific side. The Left. I have a lot of pain after the dentist numbs my mouth and I was wondering if there are any possible long term effects of the numbing medication that could cause damage to the muscle in my jaw.  I also have TMJ and i was curious if that could be a cause?

[Jerome Bogin, D.D.S.]

The anesthesia itself would not cause the problem. Intramuscular injections can cause soreness and the length of time you have you mouth open certainly will have an effect.

[dentist1]

There are no real effects of the anesthesia.  The needle goes through muscle (depending on the type of injection), so you end up with what amounts to muscle pain.  Keeping your mouth open for long periods of time can also add to the discomfort after dental appointments.

[candy7209]

A related discussion, shot in tooth muscle was started.