Whether or not a 4 year old child needs to wear a crown. It should depend on the situation; if only a small area of caries, it is generally not necessary to wear a crown; however, if the area of caries is large and has retention value, it is generally necessary to do crown restoration. If the teeth of 4-year-old children are only simple caries, and the area of caries is relatively small, you can not wear a crown restoration, filling treatment can restore the function of the teeth. However, if the degree of caries is more serious, filling treatment, etc. has been unable to restore the shape of the crown to exercise its function, it is recommended to wear a crown for restoration, which can protect the remaining tooth tissues and roots, and restore the chewing function of the tooth. If 4-year-old children appear in the dental problems, it is recommended that timely consultation, and under the guidance of a professional physician to take the best treatment, to avoid unauthorized treatment to affect the development of teeth; usually also pay attention to oral hygiene, reduce the intake of sweets.