Temporomandibular Disorder?

My jaw hurts. Has for a few days now. Initially I thought it was caused by gum chewing. You see, about a week ago I got stuck in Kroger with the slowest checkout person on earth. I didn't want to spit my gum out so I just chewed it. But I rarely chew gum. A few days later my jaw hurt when I chewed. It got better and worse, better and worse, but I assumed it was caused by the gum and was a simple case of sore muscle. But the pain is getting worse and has been with me every morning. After a little digging on WebMd I found temporomandibular disorder (TMD):

From WebMd: TMD is not just one disorder, but a group of conditions, often painful, that affect the jaw joint (temporomandibular joint, or TMJ) and the muscles that control chewing. Although we don't know how many people actually have TMD, the disorders appear to affect about twice as many women as men.

The good news is that for most people, pain in the area of the jaw joint or muscles is not a signal that a serious problem is developing. Generally, discomfort from TMD is occasional and temporary, often occurring in cycles. The pain eventually goes away with little or no treatment. Only a small percentage of people with TMD pain develop significant, long-term symptoms.

Who knows but it doesn't seem serious. I also recall some correlation to a sore jaw during long races so I'm thinking that maybe this has something to do with the helmet strap hitting my jaw for long periods of time. I generally keep my strap fairly loose, but maybe not enough so.

It's not massive pain but at times it does make me wince when chewing. It's not a sharp pain. It's more of a dull sore muscle pain in the right side of my jaw about 1/2 inch in front of my ear lobe.