Dentinogenesis imperfecta (DI) is a genetic disorder of tooth development. It is inherited in an autosomal dominant pattern, as a result of mutations on chromosome 4q21, in the dentine sialophosphoprotein gene (DSPP). It is one of the most frequently occurring autosomal dominant features in humans. Dentinogenesis imperfecta affects an estimated 1 in 6,000-8,000 people.

People with this condition have abnormal enamel, short and narrow roots, and can lack nerves. This condition can cause teeth to be discolored (most often a blue-gray or yellow-brown color) and translucent, giving teeth an opalescent sheen. Teeth are also less mineralized than normal, making them prone to rapid wear, breakage, and loss. These problems can affect primary (baby) teeth alone, or both baby teeth and permanent (adult) teeth, with the primary teeth usually more severely affected.

Although genetic factors are the main contributor for the condition, any environmental or systemic changes that impede calcification or metabolization of calcium can also result in anomalous dentin.

This is the most widely used classification for dentinogenesis imperfecta, and subdivides the condition into 3 types:

DI associated with Osteogenesis Imperfecta (OI). Type of DI with similar dental abnormalities usually an autosomal dominant trait with variable expressivity but can be recessive if the associated osteogenesis imperfecta is of recessive type.

Recent genetic studies have identified that mutations in the genes coding for the collagen type 1 proteins, COL1A1 and COL1A2, are associated with this type of DI.

Not all individuals with OI have dentinogenesis imperfecta, and the prevalence of DI varies depending on the subtype of OI:

DI not associated with OI. Occurs in people without other inherited disorders (i.e. Osteogenesis imperfecta). It is an autosomal dominant trait. A few families with type II have progressive hearing loss in addition to dental abnormalities. Also called hereditary opalescent dentin.