<unk>  can be classified according to their clinical appearances: ;Type 1 - Hypoplastic :Enamel of abnormal thickness due to malfunction in enamel matrix formation. Enamel is very thin but hard & translucent, and may have random pits & grooves. Condition is of autosomal dominant, autosomal recessive, or x-linked pattern. Enamel differs in appearance from dentine radiographically as normal functional enamel. ;Type 2 - Hypomaturation :Enamel has sound thickness, with a pitted appearance. It is less hard compared to normal enamel, and are prone to rapid wear, although not as intense as Type 3<unk> . Condition is of autosomal dominant, autosomal recessive, or x-linked pattern. Enamel appears to be comparable to dentine in its radiodensity on radiographs. ;Type 3 - Hypocalcified :Enamel defect due to malfunction of enamel calcification, therefore enamel is of normal thickness but is extremely brittle, with an opaque/chalky presentation. Teeth are prone to staining and rapid wear, exposing dentine. Condition is of autosomal dominant and autosomal recessive pattern. Enamel appears less radioopaque compared to dentine on radiographs. ;Type 4 - Hypomature hypoplastic enamel with taurodontism : Enamel has a variation in appearance, with mixed features from Type 1 and Type 2<unk> . All Type 4<unk>  has taurodontism in common. Condition is of autosomal dominant pattern. Other common features may include an anterior open bite, taurodontism, sensitivity of teeth. Differential diagnosis would include dental fluorosis, molar-incisor hypomineralization, chronological disorders of tooth development.
Amelogenesis imperfecta
Danon disease
Panayiotopoulos syndrome
Pedophilia
Progeria
Kufs disease
Xeroderma
Hawkinsinuria