We must also consider other possibilities:
* Worn teeth, mobile or missing;
* Gum problems;
* Complete or partial prosthetic poorly adjusted;
* Bad habits like biting pencils or pens.
What can you do?
1. You relax. Think about it when you tighten your teeth. Try to relax the muscles of the jaw and keep extended. If necessary, you can access courses relaxation. Check with your dentist or your doctor.
2. Monitor your diet. Avoid hard and sticky foods. Avoid chewing gum. Eat soft foods and cut them into small pieces. Try not to open the mouth too big, even yawn.
3. Massage and exercise. Like other muscles of the body, massage and exercise can help ease the achier, if made smoothly. Be careful not to do too much exercise or stretching not to aggravate the problem. 
4. Apply a compress. Your dentist may recommend that you apply a hot or cold compresses on the painful muscles of the jaw, then the massage to relax slightly. For the cold, wrap ice cubes in a towel, or use a bag of frozen vegetables - peas, for example. For the heat, use a hot water bottle wrapped in a towel, a heating pad or a hot washcloth.
5. Remember: "Lips closed, teeth apart". When you relax:
* Your teeth should be slightly apart;
* Your language should rest lightly on the palate;
* Your lips should be closed or slightly open and relaxed. Keep the upper and lower teeth to touch, except for chewing or swallowing.
6. Be optimistic. It is almost always overcome the PTM, but it is not easy. For some, it simply realize that they shake their teeth and make a sustained effort to relax. The symptoms then wears off within a few days or weeks. Others, against, will eliminate discomfort after several weeks or months of effort.