A fine structural study of coronal and root dentinogensis in the mouse: observations on the so-called 'von Korff fibres' and their contribution to mantle dentine.

The fine structure of mantle dentine formation has been studied in the mouse molar. No evidence was found for the presence of collagenous von Korff fibres arising from the dental papilla, passing between odontoblasts and fanning out to form the collagenous matrix of mantle detine. Instead, large collagen fibrils were first demonstrable in the matrix peripheral to the dential aspect of an extensive junctional complex system occurring at the necks of the odontoblasts. The orientation of the fibres was at right angles to the future amelo-dentinal junction in coronal dentinogenesis, but parallel to the root surface in radicular dentinogenesis. These large collagen fibrils formed the mantle dentine. It is concluded that von Korff fibres, as strictly defined, are artefacts. Photographs in the literature purporting to show von Korff fibres are attributable to obliquity of section. Also, is suggested that the difference in fibril orientation in coronal and root mantle dentine is the reason for the conflicting opinions on the pattern of fibril orientation in this tissue.