Subconscious teeth clenching during the day (and nighttime clenching) can put spurious signals into the trigeminal nerve, which runs through the jaw joint (tempormandibular joint). Those signals can show up as referred pain (for instance in the ear, face, jaw, migraines, tinnitus, etc.). If you want to find out how much you are subconsciously clenching (to find out if that's what's causing this), you can use a biofeedback headband in diagnostic mode (with the biofeedback sound turned off), and the headband will count the number of clenching incidents you have, and your total clenching time. If it turns out you are clenching a lot (anything more than 10 seconds per night is a bruxism habit), then you can turn the biofeedback on and start training yourself out of the clenching habit.