Unconscious teeth touching each other may be caused by neurological disorders, occlusal disorders or temporomandibular joint disorders, mental and psychological factors, etc., which need to be examined in the hospital. 1. Neurological disorders: When there are abnormalities in the central nervous system, it may cause unconscious teeth knocking against each other. 2. Occlusal disorders: when long-term missing teeth or frequent unilateral chewing, teeth misalignment, teeth grinding symptoms may also occur. 3. Temporomandibular joint disorder: due to long-term partial chewing or wear and tear of temporomandibular joints or diseases, the joints drive the jaws to move abnormally, and the teeth may also bump into each other. 4. Mental and psychological factors: emotional tension or daytime fatigue, psychological anxiety, will lead to part of the brain is in a state of excitement, caused by the contraction of the chewing muscles, resulting in teeth knocking each other. If the teeth bump into each other for a long time, it is recommended to go to the hospital to check the cause of the disease and deal with it in time, so as to avoid excessive wear and tear of teeth and damage to the joints.