Elderly people clenching their teeth may be physiological factors, but we can’t rule out periodontitis, occlusal disorders, neurological factors and other omens. 1. Physiological factors: if the elderly mental tension, excessive pressure or long-term rest may occur when the phenomenon of teeth clenching, mostly in the relief of emotions after the disappearance of the symptoms. 2. Periodontitis: it is a common oral disease, mainly related to plaque and other factors. It is mainly manifested as red gums, loose teeth, large gaps between teeth and other symptoms, and the phenomenon of teeth clenching may occur. 3. Occlusal disorders: one of the common factors of teeth clenching, mostly caused by uneven teeth on both sides, or wearing dentures that are not suitable. 4. Neurological factors: commonly caused by Parkinson’s disease, epilepsy and other diseases, can appear the phenomenon of clenching teeth in the elderly. Elderly people clenching their teeth should go to the hospital in time to avoid delaying their condition if physiological factors are excluded.