There are many reasons that cause eight-year-old children to grind their teeth in bed, because the cause of grinding itself is relatively complex, there is no particularly thorough study of the pathogenesis, clinically often considered to have a certain relationship with the following factors: 1, mental stress: the first consideration may be the recent study is more nervous, mental stress, anxiety or poor sleep, this situation can lead to night grinding; 2, the Central nervous system dysfunction: for example, some children with special neuropsychiatric diseases, epilepsy or schizophrenia, will also appear night grinding; 3, dental occlusion factors: due to various reasons resulting in poor alignment of upper and lower teeth, such as the presence of occlusal disorders, or the process of teething teeth alignment is not neat, the above factors are important causes of night grinding; 4, genetic Factors: For example, if parents or immediate family members within three generations have teeth grinding at night, the chances of children grinding their teeth at night will be significantly higher than other children of the same age; 5, dental inflammation: the presence of gingivitis, periodontitis, periapical inflammation, these cases due to local discomfort of the teeth, can also lead to night grinding; 6, gastrointestinal disorders: for example, children with food accumulation, indigestion, or the presence of intestinal parasites The situation of grinding teeth at night can be caused.