Update: Just came back from my primary doctor, and he's fairly certain that what I'm experiencing is a fairly unpleasant TMJ flare up.

He looked over the x-rays I provided him and performed several tests - including one in which he felt my face around the jaw and nearby muscles and triggered some pretty spectacular pain on my right side jaw muscle - and is fairly confident that between the sinus infection I had in November, and all of the dental work I've had done in the last few months, I've aggravated my jaw something fierce.

This makes a lot of sense to me, as my bite has been out of whack since all of this began, and that I have a tendency to chew on straws and other stuff - specifically on my right side (though usually I grind things between my canines, but it's always on the right side). I've also had crackling and popping when eating.

He also said the fact that I've lost 40lbs in the last eight months and haven't had my CPAP therapy re-evaluated leads him to believe I'm definitely either bruxing or grinding my teeth at night, which is another indicator of TMJ.

So, for now, he put my on Clindamycin to clear up what might be left of the sinus infection, and Vicodin for the evenings for the pain, and instructed me to setup a new appointment with the dentist to discuss my TMJ treatment options.

I'll post back here after I have that appointment.

Thanks again for all of the information & advice.