Table 1.

Questionnaire.

Q1	In the last 3 months, has it been pointed out to you that you make a tooth grinding sound during sleep?
Q2	Do you experience orofacial jaw muscle fatigue or pain when you are awake?
Q3	When you are concentrating on something, or during work, do your upper- and lower teeth contact each other?

All the questions were evaluated using a 5-point rating scale: 0) never, 1) hardly ever, 2) occasionally, 3) fairly often, and 4) very often.v