It is proposed this hearing loss is a secondary feature to attrition; this type of tooth wear can cause jaw overclosure with subsequent changes to the shape of the inner ear, thus causing hearing loss. However, the true cause remains unknown. Type III
Similar clinical and radiographic features to that of type I and II are apparent for the adult (permanent) teeth. The main distinguishing feature is "shell teeth", a term used to describe the unique appearance of the baby (primary) teeth; the primary teeth have multiple pulp exposures and radiographically appear hollow as the dentine layer is thin (dentine hypotrophy) and the pulp chamber is very large. Histology
The enamel has a regular structure, however, there are abnormalities in the structure of dentine and at the amelo-dentinal junction. These abnormalities include:

Fewer dentinal tubules
Dentinal tubules may be of smaller diameter, irregular in shape, and may also be obliterated
Abnormal morphology of apatite crystals
Higher water and collagen content in the organic component of dentine (see Structure section on dentin page to learn more)

Diagnosis
To determine if the condition has been inherited, it is suggested to ask if any other family member has Dentinogenesis imperfecta.
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.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 weaker than normal, making them prone to rapid wear, breakage, and loss. These problems can affect baby (primary/deciduous) teeth alone, or both baby teeth and adult (permanent) teeth, with the baby teeth usually more severely affected.Although genetic factors are the main contributor for the disease, any environmental or systemic upset that impedes calcification or metabolisation of calcium can also result in anomalous dentine. Classification
Shield classification (1973)
This is the most widely used classification for dentinogenesis imperfecta, and sub-divides the condition into 3 types:

Type I
DI associated with Osteogenesis Imperfecta (OI).