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Anethesia causes muscle rigidity



Junior member
Oct 2, 2011

I have two problems with anesthesia. 1) Often it doesn't work very well, requiring repeated shots and sometimes painful procedures 2) It can cause my masseter muscle to go stiff and rigid, and it becomes difficult to open my mouth, particularly if the shot is in the lower jaw near the back. In the past some dentists have done well in this regard, and others have not. Things seem to have gotten worse in the last several years. I wonder if this might be due to the particular anesthesia being used, and if dentists can switch. Also, I wonder if dentists haven't started using newer, different anesthesias. And, perhaps this might be the cause of the problem.


Hi,2) It can cause my masseter muscle to go stiff and rigid, and it becomes difficult to open my mouth, particularly if the shot is in the lower jaw near the back.

I have dealt with this issue. I noticed that it is worse when they hit a certain nerve when placing the needle in my lower jaw, which sends shooting pain down my jawbone. The first time this happened it made me panic and I was tensing the muscle out of being surprised by the pain and anxiety. It took about 4 days for it to finally stop hurting me. The next time they did this, the dentist (a different one this time) did not hit that nerve and I knew what to expect so I wasn't so surprised - I had some stiffness but not much.

So it could possibly be that they are touching a nerve that is causing this.

What helped me speed up the process of the stiffness and pain is to massage my cheek in that area (fingers inside and out and gently squeezing in circles), plus otc pain meds and even sleeping on that side seemed to help it out (maybe the extra heat between my cheek and pillow?).

What I found out that made it way worse was trying to open and close my jaw, chewing food (after 5 minutes I had to rest my jaw), and talking.

When I mentioned this to my dentist, she didn't seem to be surprised or offer up any suggestions on what to do, so I've kind of just played it by ear. I treat it like a sore muscle, so of course massage, heat, and otc pain meds will help (at least for me).
Thanks AngelDove for your reply. I don't really feel like the dentist is hitting a nerve, but I'll discuss with my dentist. There is no sharp pain sensation, just a progressive muscle tightening over a few minutes. The biggest problem is that it is hard to keep my mouth open during the procedure - uncomfortable, and after a while it's downright painful. It is also harder for the dentist to work since my mouth won't fully open. Afterwards I'm not so concerned with this since I can find relief by keeping my mouth closed. I had a DNA test that indicated that I might have malignant hyperthermia. Although dental anesthesia is said not to bring on an attack, I wonder if this isn't a very local and therefore much less severe form of the reaction. Either way, I think (I would guess?) that there is some sort of chemical interaction with either the masseter muscle or the nerves that enervate it. At least that is what it feels like.
It can happen on anyone with a traditional injection find someone who routinely uses PDL injections instead.