Occasionally when I yawn a painful lump bulges up on the underside of my chin, between my Adam’s apple and the boney point of my chin. Sometimes it will happen several times in a week, other times I can go months without it happening. I had surgery on my jaw seven years ago, and I can’t ever remember having this happen prior to that time. The basic chain of events is: 1) I have a big, gaping yawn; 2) I notice extreme pain under my chin; 3) I notice a hard, walnut-sized lump has formed under my chin (my wife says it’s not visible – she usually can’t figure out why I get a funny look on my face after yawning); 4) I try my best to relax and stop yawning; 5) 30-60 seconds later, the bump and pain subside. Occasionally the bump is barely detectable quite a while later, but it usually disappears within a couple minutes.
Is this just some sort of cramp? Could it be related to my jaw surgery, or is this likely a false case of cause and effect? What, if anything, can I do to stop this from happening, or at least minimize the pain?