I would agree that you should call doctor as a cautionary measure. I have not had jaw surgery, but I can tell you that yawning is always a painful experience for me, due to a combination of the fibrosis from radiation and nerve impact of the neck dissection. Every now and then, the muscle will actually spasm while I am yawning, and the pain is excruciating -- actually brought me to my knees once or twice. The acute pain passes quickly, but it takes a bit for the residual aching to die down. Another fellow patient, a 3 year survivor, has the same thing, though he says the frequency goes down over time.

Get it checked out and let us know. We will be keeping you all in our thoughts.