I know it sounds weird, but try chewing gum. It keeps you from clenching your jaw. Sugar free gum, of course LOL.Several years ago, my dentist noted that my teeth were showing signs of wear that suggested grinding during sleep, or some other tension-related response.
Yesterday, I had an emergency visit to my dentist - my symptoms was pain when chewing. After an extensive series of x-rays and tests, the dentist concluded that my problem was not a tooth/dental problem, but rather TMJ - a problem that can be caused by a number of factors including grinding of the teeth and tension. His suggestion was to shift to a diet of softer foods for a week, combined with ibuprophen.
So the point is that this is a real concern, and intense focus creates stress that can have painful consequences.
Intellectually, I know that my best turning results from being relaxed about what I'm doing. But like many others, I often find myself focusing very hard to what I'm doing, and tensing up in a way that I know doesn't produce the best results. And my dentist would add that it's not healthy. And my credit card says that the cost of treatment isn't cheap.