Tooth enamel overall process of tooth development. Under a microscope, different cellular aggregations are identifiable within the tissues of a developing tooth, including structures known as the enamel organ, dental lamina, and dental papilla. The generally recognized stages of tooth development are the bud stage, cap stage, bell stage, and crown, or calcification, stage. Enamel formation is first seen in the crown stage. Amelogenesis, or enamel formation, occurs after the first establishment of dentin, via cells known as ameloblasts. Human enamel forms at a rate of around 4 μm per day, beginning at the future location of cusps, around the third or
Human tooth otherwise preventing crowding and/or spacing. If a primary tooth is extracted before its succeeding permanent tooth's root reaches ⅓ of its total growth, the eruption of the permanent tooth will be delayed. Conversely, if the roots of the permanent tooth are more than ⅔ complete, the eruption of the permanent tooth will be accelerated. Between ⅓ and ⅔, it is unknown exactly what will occur to the speed of eruption. Some systemic disorders which may result in hyperdontia include Apert syndrome, cleidocranial dysostosis, Crouzon syndrome, Ehlers–Danlos syndrome, Gardner's syndrome, and Sturge–Weber syndrome. Some systemic disorders which may result in hypodontia