Baby incisors only grow one, part of it is normal, part of it may be caused by malnutrition, missing teeth or eruption obstacles and other abnormalities. 1. Normal situation: small babies usually start to erupt milk teeth at around 6~10 months, usually the lower incisors first, can be two incisors at the same time, may also be the first one, and then the second one, the interval may be 1~3 months, so the small baby has just grown an incisor, can be observed for three months. 2. Abnormalities: (1) malnutrition: inadequate feeding and unbalanced diet will affect the baby’s growth and development, and will also lead to the backward eruption of teeth. Babies with low growth and development or bad dietary habits in general need to go to the hospital for a face-to-face consultation, and under the guidance of the doctor for conditioning and nutritional supplementation. (2) missing teeth or teeth eruption obstacles: baby milk teeth after the loss of a long time without eruption of permanent teeth, or before the milk teeth have stunted or injured premature fall, may affect the eruption of permanent teeth, need to go to the hospital to take a picture, a further examination to clarify the root of the tooth situation, there are difficulties in the eruption of the need for early surgery. It is recommended to strengthen the diet and nutrition, do a good job of oral cleaning and care, and regular medical checkups. Baby incisors do not grow for a long time, must go to the hospital for an interview and examination, to clarify whether there are pathological factors and timely treatment, so as not to affect the baby’s health.