Eleven months baby teeth a little yellow may be caused by the oral cavity is not clean, may also be caries, dental fluorosis and so on. 1. Oral unclean: If eleven months baby eat orange, carrot and other yellow food after not timely clean oral cavity, may lead to baby teeth a little yellow. This is a normal physiological phenomenon, can not be treated. 2. caries: caries is due to oral microbial infection, often eat sugary foods and other factors. The patient will appear to reduce the transparency of the teeth, tooth enamel indicates the appearance of yellowish-brown or brown pigmentation, so eleven months baby caries, will be manifested in the teeth a little yellow. 3. dental fluorosis: if eleven-year-old baby enamel development period intake of excessive fluoride, vitamin D intake is insufficient may lead to dental fluorosis. Patients will be manifested as a loss of tooth enamel luster, tooth enamel indicates the appearance of yellow-brown, dark brown, black-brown changes. It is recommended that eleven-month-old baby teeth are a little yellow, parents need to take their children to the doctor in time. If it is caused by oral uncleanliness, no treatment is needed. If it is caused by disease, it needs to be treated for the cause.