Grinding of teeth, referred to as bruxism, is a result of a variety of causes which may be stress or anxiety of an exam or work, or due to sleep apnea, at night, being performed involuntarily as you are asleep. This may lead to damage to the teeth/ caps over the teeth, morning jaw pain, TMJ problems, headaches, etc. Doctors counsel patients and provide bite guards, which can be hard or soft, and can be placed on either or both the sets of jaw teeth.