Definition: Genetic disturbances in dentin formation leading to altered morphology of dentin. The teeth will appear bluish gray. There are three identified types (I, II, III). Type I is associated with osteogenesis imperfecta.
Shape: Bulbous crowns with short and slender roots.
Internal: Radiopaque, same radiopacity as dentin. No or small pulp chamber and root canals present.
Number: Associated with all teeth in the oral cavity.
(click image to enlarge)
(note the bulbous crowns and absent pulp chambers and root canal)