One year old has not grown teeth may be related to the child’s diet is too fine, vitamin deficiency, heredity and so on. 1. Diet too fine: one year old children eat too fine food, food is too soft, single diet, the gums can not be very good with the friction of hard objects, causing difficulty in the eruption of milk teeth. 2. Vitamin deficiencies: Vitamin D deficiency, for example, may cause late teething. 3. Heredity: If someone in your family has late teething and there is no other abnormality other than late teething, it may be caused by heredity. There may be other reasons why the child does not have teeth at the age of one, so it is recommended that the child go to the hospital in time to improve the examination and clarify the cause of the disease, and then be treated under the guidance of the doctor.