Why is it,when the dentist applies novocaine, that the benumbed facial features feel hugely swollen (though the mirror confirms that they are exactly their normal size)? Why, for example, wouldn’t it be equally likely for them to feel small and shrunken? Or loose? Or any other sensation?
I think a big part of it is that your face IS swollen most of the time after using lidocaine/novocaine. It’s not a result of the drug per se, but of what has happened. They often inject it into the site and then pull/drill/cut/chisel/stitch/screw/etc on whatever seems to be the problem. There is some natural swelling that takes place in response to this trauma. It might not be obvious to the eye, but a small amount of swelling is very noticeable to the nerves. (Just ask anyone with a sinus infection).
Other than that, I’ve noticed that when I wake up with a numb hand, my brain often tries to explain the sensation by assuming my hand is wrapped in a blanket or something so that it isn’t directly touching or being touched by anything else.