While bruxism is typically associated with stress, it may also be triggered by abnormal occlusion (the way the upper and lower teeth fit together), or crooked or missing teeth.
No.
Yes, it can definetly be a factor. Panic attacks during sleep, as well as general stress and anxiety, can cause grinding and clenching.
A person may do something like clench their teeth during a seizure, but epilepsy does not cause bruxism.
bruxism is grinding of the teeth, typically accompanied by clenching of the jaw