A histological study of dentin formation in osteogenesis imperfecta congenita

The developing deciduous teeth in three cases of osteogenesis imperfecta congenita were studied with routine histological stains, electron microscopy, and a silver impregnation method for nerves. The odontoblasts differentiated normally and assumed a columnar form and regular arrangement while pre‐dentin was forming, but after tooth formation was initiated normal development deteriorated. With the onset of mineralization, the odontoblasts changed to polyhedral cells with no definite orientation. The structure of the dentin was the same in all teeth and consisted of coarse fibrous circumpulpal dentin covered by a normal tubular mantle layer 20μm thick. Electron microscopy revealed that collagen fibers were evenly distributed in early pre‐dentin but later were grouped together in large bundles which entered hillocks of dentin matrix. These large collagen fiber bundles may be von Korff fibers. Studies of nerves, although not conclusive, indicated abnormal patterns of nerve growth and it is possible that the abnormal connective tissue was responsible for the apparent disorderly arrangement of the nerves. It is also suggested that developing teeth in osteogenesis imperfecta and dentinogenesis imperfecta could be used as experimental models to study normal mechanisms of dentinogenesis.