Table 1: Questionnaire.

Question item Abbreviated form
Q1 If you open your mouth wide, can you fit 3 fingers held vertically in your mouth? Limited mouth opening
Q2 Do you experience pain in the face, jaw, temple, or in front of the ear when you open and close your mouth? Mouth-opening pain
Q3 Can you open your mouth without any deviation? Mouth-opening deviation
Q4 Do you experience pain in the face, jaw, temple, or in front of the ear when you eat hard foods such as beef jerky, dried cuttlefish, or octopus? Chewing-induced pain
Only instrument players answered the following questions
Q5 Do you play the instrument with your head tilted forward? Head tilted forward
Q6 Do you play the instrument with incorrect embouchure*? Incorrect embouchure
Q7 Are you using an instrument with strong mouthpiece resistance? Strong resistance
Q8 When you play the instrument, do you press the mouthpiece against your mouth? Pressure from the mouthpiece
Q9 How many years have you played the instrument? Years of experience
Q10 How many hours per day do you play the instrument? Playing time per day

The subjects were asked to answer question items 1-8 on a 5-point numeric rating scale.
Item1,3: 0) strongly agree,1) weakly agree, 2) neither agree nor disagree, 3) weakly disagree, or 4) strongly disagree. Item 2, 4-8: 0) strongly disagree,1) weakly disagree, 2) neither agree nor disagree, 3) weakly agree, or 4) strongly agree.
* The form and function of the mouth while playing the instrument