How long the nighttime irritability lasts during teething is mainly related to the child’s specific situation and should be analyzed in detail rather than generalized. In general, teething begins 4-6 months after birth and continues until the milk teeth are complete at two and a half years of age. Between the ages of 5-13, permanent teeth gradually replace milk teeth. And wisdom teeth erupt between the ages of 18-25. Therefore, tooth eruption is a relatively slow and long-term process. During the teething period, children may experience symptoms such as restlessness at night, which is a normal physiological phenomenon and the exact duration varies from person to person. Usually, the symptoms of teething of milk teeth last for about 1-2 years, while the symptoms of teething of permanent teeth last for about 6-7 years or even longer. During the teething period, good maintenance of oral hygiene is recommended, and irritability symptoms can be relieved by distraction and other means. Meanwhile, activities can be increased appropriately during the day to ensure easy sleep at night.