I can't recommend anything on the potassium, but did the cramp happen after you yawned hard? I have that happen sometimes and I actually sometimes have to push the tightened muscle back up inside my jaw until it relaxes.
Discussion
Yes, actually. It was very annoying.
Yeah, it's wild! It just happens out of the blue for me. I don't know what causes it. Even when I have enough potassium in my diet, it seems to just happen sometimes. The best thing I can do is to just press my fist against the underside of my chin as I yawn to prevent the muscle from tensing too hard. Or, avoid yawning widely, though that's easier said than done sometimes haha