The common causes of teeth grinding in sleep are mainly mental factors, neurological factors, occlusal factors, genetic factors, local irritation factors, and so on. 1. Mental factors. Mental anxiety, depression, nervousness, etc. can cause teeth grinding in sleep. 2. Neurological factors. Epileptic pa, jinson disease, schizophrenia taking acetylcholine drugs, sedative drugs and so on. This may affect the central nervous system, which can lead to teeth grinding in sleep. 3. Occlusal factors. Long-term teeth tilt, sideways chewing, inappropriate dentures, etc. can cause occlusal disorders. This will cause teeth grinding in sleep. 4. Genetic factors. Teeth grinding in sleep may be related to heredity. 5. Local irritation. Periodontitis can cause teeth grinding, and the reason is still unknown. The exact cause of teeth grinding in sleep has to be examined and diagnosed by a doctor in a regular hospital.