Breast teeth just eruption period of the baby, the upper teeth only one, parents do not have to worry too much, because children’s milk teeth teeth individual differences are very large, the two upper front teeth are not absolutely in the same period of time together eruption, two incisors eruption of the existence of the time difference of three months are normal. If a child at the age of six is in the teething stage and only one permanent front tooth has erupted and the permanent tooth of the other incisor is not erupting, he or she should go to the hospital for a further examination. X-rays need to be taken to observe whether there is any abnormality in the position of the incisors, the direction of the eruption, and the morphology of the roots of the incisors. If the milk incisors have long-term apical inflammation, it will also cause abnormalities in the morphology and root morphology of the succeeding permanent anterior teeth, which will lead to delayed eruption of the incisors or fail to erupt on their own. In addition, the premature loss of the milk anterior teeth will also delay the eruption of the succeeding permanent teeth, in which case the succeeding permanent teeth have to be assisted in the eruption process.