- Malted teeth: (dental fluorosis) in case of having water supply with more than 2 (less than 4) ppm fluoride white sopts will appear on enamel without radiological manifestation. At more than 4 ppm fluoride brown sopts will occur without radiographic any appearance. If the mount of fluoride reaches 30 ppm, the enamel not only badly stained but fractures easily. The teeth can be ragged which can be seen on radiographs.
- Amelogenesis imperfecta : that is defective enamel formation resulted from a group of hereditary diseases. Amelogenesis can be divided to: Hypoplastic: Enamel is seen thin on radiographs with teeth spacing. Hypocalcification and hypomaturation: the enamel has weak consistency that can be easily broken off. On radiographs abnormal thickness with multiple defects can be seen on enamels.
- Dentinogenesis imperfecta: type I includes osteogenesis imperfecta and type II does not. Radiographic features are: obliteration of pulp, short roots, bulbous crown with a marked constriction at cementoenamel junction ( tulip teeth).
- Shell teeth: enamel and dentine are thin with a large pulp chamber.