The only thing we can come up with it's stress related perhaps from the attack on New York, and in all likelihood that's what it is. Elsa agrees with the theory, admitting she worries more about her safety these days. But she had no idea she was grinding her teeth. I'm grinding my teeth. Muscle relaxers and anti-inflammatory drugs helped Elsa.
Every case is different, of course.
If you think you may be grinding your teeth, contact your doctor.