The baby sleeps and grinds his teeth at night, considering that it may be related to mental factors, dentition factors, local stimulation factors and other reasons. 1. Mental factors: the baby’s recent mental stress is too large, long time in a state of tension and anxiety, easy to induce teeth grinding. 2. Dental factors: the baby’s teeth growth and development abnormalities, such as long-term missing teeth lead to neighboring teeth tilt, sideways chewing lead to uneven wear and tear of both teeth, may lead to the baby’s night sleep teeth grinding. 3. Local stimulation: the baby usually do not pay attention to personal hygiene with periodontitis, local inflammation stimulation may also lead to the baby sleep grinding teeth at night. It is recommended to go to the stomatology department of the hospital as soon as possible to clarify the specific causes of the baby’s teeth grinding at night.