A conttibution to the problem of dentin innervation in man
1960 Volume 34 Issue 4-5 Pages 419-447
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1960 Volume 34 Issue 4-5 Pages 419-447
In the present paper the p roblem of the dentin innervation was reinvestigated and discussed chiefly in relation to the progress of the odontogenesis, and the following points should be emphasized.
1) The so-called Raschkow's nerve plexus in the pulp appears to be formed there by the mechanism that the nerve fibers supplying the layer under the odontoblasts are pushed back toward the pulpal tissue by the scrum wall of the odontoblasts which move toward the pulp in the process of the odontogenesis.
2) The innervation of the layer of odontoblasts may take place in such a way that when the scrum wall of the odontoblasts becomes emaciated and loosened at the last period of odontogenesis, some of the nerve fibers enter the layer of odontoblasts through the loose intercellular spaces.
3) The t a ngential arrangement of nerve fibers in the predentin may be explained by the mechanism that when the nerve fibers come to the predentin-odontoblastic junction through the odontoblastic layer, they are obliged, because of their probable anti-tro pic nature against the bone and bone-like tissue, to change the direction in order to avoid and escape from the predentin.
4) The predentin innervation maybe understood by two mechanisms that 1) the nerve fibers in the junction are embedded into the predentin in the later period of the odontogenesis in situ and that 2) the fine fibrils ramifying from the nerve fibers in the junction extend into the predentinal tubules along Tomes' fibers for a short distance.
5) The dentin is partially innervated in the sense that the nerve fibers in the predentin are embedded into the calcified dentin matrix in the later period of the odontogenesis. It is very questionable whether or not the nerve fibers embedded in the dentin matrix are kept in physiological or intact conditions. The authors would like to consider that the nerve fibers are undergoing degeneration in the matrix, but this problem should be settled by further studies.
