Baby teeth clenching is relatively common in the clinic, the vast majority of physiological reasons, physiological common in the baby before teething to the milk teeth out of the teeth during this period of time, is because of teething, itchy teeth plate, gums soreness and discomfort, which leads to the baby clenching, biting, drooling more and grinding teeth when sleeping and so on. Baby teeth clenching is also seen in some pathological conditions, common in the following areas: First, is a lack of calcium and vitamin D, chewing muscle excitability, to the night obvious. Second, it is caries, toothache, gum inflammation, baby teeth can relieve. Third, it is dentin allergy, seen in allergic babies. Fourth, it is intestinal parasites, mostly seen in babies over six months of age, such as intestinal roundworms grinding teeth at night. Fifth, it is convulsions or epilepsy, the baby’s neurodevelopmental imbalance and nerve impulses, easy to generalize, resulting in fever, irritation, infection can be caused by clenching teeth.