Doctors don't completely understand what causes bruxism. Possible physical or psychological causes may include:
- Emotions, such as anxiety, stress, anger, frustration or tension
- Aggressive, competitive or hyperactive personality type
- Abnormal alignment of upper and lower teeth (malocclusion)
- Other sleep problems, such as sleep apnea
- Response to pain from an earache or teething (in children)
- Stomach acid reflux into the esophagus
- An uncommon side effect of some psychiatric medications, such as phenothiazines or certain antidepressants
- A coping strategy or focusing habit
- Complication resulting from a disorder such as Huntington's disease or Parkinson's disease