Teeth grinding during the day and not at night can be caused by a number of factors, including childhood teeth grinding, parasitic diseases, mental stress, and oral diseases. 1. Children’s teeth grinding period: in the process of children’s teeth eruption, due to the teeth eruption in the mouth will lead to oral discomfort and thus triggering teeth grinding. 2. Parasitic diseases: daytime grinding of teeth at night is not grinding teeth, may also be a manifestation of internal parasites such as roundworms, in addition to decreased appetite and other adverse symptoms. 3. Mental stress: when the work intensity is too large, the spirit of long-term anxiety and depression or mental depression, may also appear during the day grinding of teeth. 4. Oral disease: Oral malocclusion or long-term missing teeth on one side, unilateral chewing, temporomandibular joint disease may trigger involuntary teeth grinding. Teeth grinding is usually multifactorial, specific also need to go to the hospital to find the cause of the disease according to the oral and systemic conditions.