Anomalies of structure can be divided into disturbances in structure of enamel (enamel hypoplasia, enamel hypocalcification, amelogenesis imperfecta, dental fluorosis), dentin (dentin dysplasia, dentinogenesis imperfecta, dentin hypocalcification) and cementum (hypercementosis).
Enamel hypoplasia is the defect of the teeth in which the tooth enamel is hard but thin and deficient in amount. This is caused by defective enamel matrix formation with a deficiency in the cementing substance. Enamel hypocalcification is a defect of tooth enamel in which normal amounts of enamel are produced but are hypomineralized. In this defect the enamel is softer than normal. Amelogenesis imperfecta presents with abnormal Anomalies of structure formation of the enamel or external layer of teeth. Enamel is composed mostly of mineral, which is formed and regulated by the proteins in it. Amelogenesis imperfecta is due to the malfunction of the proteins in the enamel. Dental fluorosis is a developmental disturbance of dental enamel caused by excessive exposure to high concentrations of fluoride during tooth development. Dentin dysplasia is a genetic disorder of teeth characterized by presence of normal enamel but atypical dentin with abnormal pulpal morphology. Dentinogenesis imperfecta is a genetic disorder of tooth development. This condition causes teeth to be discolored (most often a blue-gray or Anomalies of structure yellow-brown color) and translucent. Hypercementosis is characterized by the excessive buildup of normal cementum on the roots of one or more teeth.