Human tooth development the formation of odontoblasts continue from the tips of the cusps, the odontoblasts secrete a substance, an organic matrix, into their immediate surrounding. The organic matrix contains the material needed for dentin formation. As odontoblasts deposit organic matrix termed predentin, they migrate toward the center of the dental papilla. Thus, unlike enamel, dentin starts forming in the surface closest to the outside of the tooth and proceeds inward. Cytoplasmic extensions are left behind as the odontoblasts move inward. The unique, tubular microscopic appearance of dentin is a result of the formation of dentin around these extensions. After dentin formation begins,
Human tooth development through cementum. NGF-R is present in the condensing ectomesenchymal cells of the dental papilla in the early cap stage tooth germ and plays multiple roles during morphogenetic and cytodifferentiation events in the tooth. There is a relationship between tooth agenesis and absence of the peripheral trigeminal nerve (see Hypodontia). All stages (bud, cap, bell, crown), growth and morphogenesis of the teeth are regulated by a protein called sonic hedgehog. Various phenotypic inputs modulate the size of the teeth. Parathyroid hormone is required for tooth eruption. The following tables present the development timeline of human teeth. Times for the initial calcification