Dentinogenesis imperfecta is a genetic disorder of tooth development. This condition causes teeth to be discolored (most often a blue-gray or yellow-brown color) and translucent. Teeth are also weaker than normal, making them prone to rapid wear, breakage, and loss. These problems can affect both primary (baby) teeth and permanent teeth. This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Dentinogenesis imperfecta affects an estimated 1 in 6,000 to 8,000 people. A genetic disorder, or genetic disease is a disease caused by abnormal expression of one or more genes in a person causing a clinical phenotype. ... Radiograph of lower right (from left to right) third, second, and first molars in different stages of development. ... Types of teeth Molars are used for grinding up foods Carnassials are used for slicing food. ... An autosomal dominant gene is an abnormal gene on one of the autosomal (non-sex determining) chromosomes. ...

Researchers have described three types of dentinogenesis imperfecta with similar dental abnormalities. Type I occurs in people who have osteogenesis imperfecta, a genetic condition in which bones are brittle and easily broken. Dentinogenesis imperfecta type II and type III usually occur in people without other inherited disorders. A few families with type II have progressive hearing loss in addition to dental abnormalities. Type III dentinogenesis imperfecta was first identified in a population from Brandywine, Maryland. Researchers now believe that type II and type III may be the same disorder. Osteogenesis imperfecta (OI), commonly known as brittle bone disease, is a group of genetic bone disorders. ... Brandywine is a census-designated place located in Prince Georges County, Maryland. ...

Mutations in the DSPP gene have been identified in people with type II and type III dentinogenesis imperfecta. Type I occurs as part of osteogenesis imperfecta, which is caused by mutations in one of several other genes. The DSPP gene provides instructions for making three proteins that are essential for normal tooth development. These proteins are involved in the formation of dentin, which is a bone-like substance that makes up the protective middle layer of each tooth. Mutations in the DSPP gene may affect the proteins made by the gene, leading to the production of abnormally soft dentin. Teeth with defective dentin are discolored, weak, and more likely to decay and break. It remains unclear how DSPP mutations lead to hearing loss in some families with dentinogenesis type II. This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... Parts of a tooth, including dentin Dentin (BE: dentine) is the substance between the enamel (substance in the crown) or cementum (substance in the root) of a tooth and the pulp chamber. ...

This article incorporates public domain text from The U.S. National Library of Medicine