When children start to have teeth at the age of 5-6, as the baby teeth fall out and the permanent teeth erupt, careful parents will find that the newly erupted incisors are jagged and the new teeth are yellowish in color, unlike the baby teeth which are white. In fact, this is a normal behavior, the incisors are fused by three developmental lobes in the process of development, so the fusion of the developmental lobes appears jagged. Why are the adult incisors not serrated? It is because the serrations of the front teeth will slowly wear down with chewing and wear. Also, because the permanent teeth are well mineralized, the outer layer of enamel is more transparent and the yellow color of the inner dentin is projected, so the permanent teeth look more yellow than the baby teeth. Parents should not worry too much about this.