Nocturnal teeth grinding is a common problem, very common in toddlers and preschoolers, the incidence is the same for both sexes, most children get better around the age of 6, and some will continue into adolescence or even adulthood. The prevalence is high (up to 40%) if 1 grinding per week is considered molarity, and decreases (up to 6%) if 3 grinding per week is considered molarity. Most teeth grinding occurs during light sleep, with about 10% occurring during the rapid eye movement period. The cause of teeth grinding: there is no definite conclusion. 1. Psychological factors: There is no evidence to prove or deny that nighttime teeth grinding is related to psychological factors in children younger than 5 years old, and the American Academy of Pediatrics even more so: teeth grinding does not mean that your child is having nightmares (usually in the second half of the night when dreams are most stressful) or reproducing daytime frustrations. However, in children aged 6-11 years, nocturnal teeth grinding is highly correlated with psychological factors (stress, tension, personality constraint), and likewise, psychological factors during adolescence (nervousness in thinking and behavior, antisocial personality disorder) are also associated with nocturnal teeth grinding; 2. Neurological factors: teeth grinding episodes are accompanied by a markedly elevated brief awakening, increased electrical activity in the cerebral cortex, as well as exhibiting irregular breathing and an accelerated pulse, so it is believed that Teeth grinding disorder is related to autonomic nervous system dysfunction, dopamine system, awakening stimuli from within and outside the organism, caused by activation of the brainstem masticatory motor area through the activation system, resulting in masticatory muscle activity. It is a manifestation of sleep disorder and belongs to sleep-related movement disorder; 3, dental occlusion disorder (teeth misalignment): still controversial, some scholars believe that any form of dental occlusion disorder will lead to abnormal contact of teeth, interfering with normal chewing, patients will involuntarily eliminate this interference through jaw movement, forming masticatory muscle contraction triggering teeth grinding disorder. Surveys have shown that the incidence of night grinding is significantly higher in people with dental occlusion problems. However, there are also scholars who experimentally prove that night grinding and bite disorder are unrelated; 4, tooth pain: the American Academy of Pediatrics believes that tooth pain caused by various reasons is the main cause of children’s night grinding, such as teething, upper respiratory tract infection, otitis media, etc. resulting in toothache; 5, intestinal parasites: it is believed that intestinal parasitic activity and the toxins secreted by them enter the human body, stimulating the corresponding parts of the brain of the sleeping person, causing chewing However, so far there is no evidence to prove that intestinal parasites and teeth grinding are related; 6, hereditary (genetic): night grinding teeth have family heredity, some studies suggest that autosomal dominant inheritance. Japanese research in 2012 suggested that the c allele carrier single nucleotide polymorphism rs6313 of HTR2A may be related to night grinding; 7, sleep position: sleep position is associated with night grinding. Lateral and prone position (sleeping on the stomach, or lying on the stomach, head to the side) when the night grinding teeth than the supine position increased, the reason is unknown, speculation may have some relationship with the incomplete opening of the airway in the prone position, there are also studies which believe that when sleeping in the lateral or prone position, the lower jaw needs to force to support the abnormal head and neck position, resulting in a high degree of tension in the temporomandibular joint and its accessory muscle tissue, resulting in unconscious muscle tremor action, and ultimately 8, some domestic studies believe that children’s gastrointestinal tract malfunction, too much dinner, too much food before bedtime, vitamin D deficiency, etc. and teeth grinding are related, but these are still to be proven. The hazards of night grinding 1. affect the quality of sleep and growth and development: teeth grinding is a sleep disorder, resulting in a reduction in deep sleep time, delayed awakening time, poor sleep efficiency, resulting in poor energy recovery and daytime fatigue; in addition, it will affect the secretion of growth hormone during deep sleep, resulting in impaired growth and development of children; there may also be a reduction in rapid eye movement sleep time, affecting children’s nervous system and intellectual development; 2. affect Teeth and periodontal tissues: grinding teeth at night without food cushioning is equivalent to dry grinding, which can cause damage to tooth enamel, thus causing dentin hypersensitivity and toothache when eating; in severe cases, it can lead to gum recession, loss of alveolar bone, loose teeth or even loss; 3. Affect facial muscles, TMJ and face shape: heavy night grinding can lead to facial muscle pain, and in severe cases, headache and neck and back pain. Muscle pain, abnormal tooth occlusion, change in vertical height between jaws, and displacement of joint discs also directly affect the normal form and function of the temporomandibular joint, leading to abnormal opening and closing mouth movements, pain at the jaw joint, and joint popping and other symptoms. Children who grind their teeth at night will have hypertrophy of the chewing muscle (because they keep using it ah), making the lower end of the child’s face bigger and changing the shape of the face. Severe teeth grinding: grinding sound during sleep lasts for 6 months and is heard at least 3-5 nights a week; tooth wear; uncomfortable bite muscle after waking up in the morning; hypertrophy of the bite muscle when clenching teeth. Treatment of teeth grinding: There is no accepted treatment for nocturnal teeth grinding, and the evidence for pharmacological treatment is insufficient, with no reports of children using related medications. 1, although the relationship between diet and night grinding is not clear, but to ensure that the child’s reasonable and balanced nutrition, do not eat too much before going to bed is always wrong; 2, psychological counseling: to understand whether there is anxiety, tension, dissatisfaction, fear, etc., the child to the corresponding reassurance, relieve the psychological pressure may reduce the occurrence of children’s night grinding teeth. Regular sleep, do not strenuous activities before going to bed, receive too much sound, picture stimulation, give the child a hot bath before sleep, listen to a soothing music, read a fairy tale can help relieve night grinding; 3, the recommended position for children to sleep is supine position, if the child prone or side lying cause children grinding teeth, help children to adjust over; 4, bite intervention treatment: there are teeth misalignment, bite jaw relationship misalignment should be corrected. However, there is no clear evidence that nocturnal teeth grinding can be treated by occlusal intervention, for example, by adjusting the balance of the occlusal surface, correcting alignment, etc.; 5, found to have intestinal parasites, should be dewormed under the guidance of a doctor; 6, if night grinding cannot be corrected, can go to the hospital stomatology department for a dental pad called teeth grinding orthodontic appliance, worn between the upper and lower teeth at night when sleeping, to prevent night grinding and protect teeth.