Dentin dysplasia is a genetic disorder of teeth, commonly exhibiting an autosomal dominant inheritance. It is characterized by presence of normal enamel but atypical dentin with abnormal pulpal morphology. There are two types. Type I is the radicular type, and type II is the coronal type. In the radicular type, the roots of teeth are shorter than normal and the pulp chamber may be nearly gone. The pulp chamber is sometimes described as having a "crescent shaped" appearance. In the coronal type, the pulps are enlarged and are described as having a "thistle tube" appearance, in permanent dentition. In the deciduous dentition, coronal dentin dysplasia bears a resemblance to Dentinogenesis Imperfecta type II.
Type 1: Roots are short, blunt and conical. In deciduous teeth, pulp chambers and root canals are completely obliterated in permanent they may be cresent shaped.
Type 2: The pulp chamber of the deciduous teeth become obliterated in deciduous teeth. While in permanent teeth, large pulp chamber is seen in coronal portion of the tooth - referred to as thistle tube appearance.Pulp stones may be found.
Type 1: Normal dentinal tubule formation is blockedand new dentin forms around obstacles...known as lava flowing around boulders.