Pulpitis

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Hopewell-Smith: Some Observations on the Dental Pulp

The causation and pathology is difficult to determine. Wedl, in his Atlas of the Pathology of the Teeth," gives drawings which resemble this odontome more closely than any other that I have found in dental or surgical literature. In his case a deciduous mandibular right canine and first molar were extracted from the mouth of a boy aged11i. These consisted of a large, hard mass which microscopically was seen to be composed of a dentine-like, calcified material uniting the roots of the two teeth. It was evidently not considered to be made up of hyperplasic cementum, nor was there any osseous ankylosis present. The same applies to the case under notice. The absence of pain so definitely stated in the history of the case, rulesout the evidence of any reactions of an inflammatory nature. The mass may have been occasioned by an overgrowth of vestigial remains, but in the present state of our knowledge it is impossible to say.

Some Observations on the Histology, Physiology and Pathology of the Dental Pulp. By Professor ARTHUR HOPEWELL-SMITH, M.R.C.S., Sc.D.
PROBABLY no subjects in the field of research have engaged theattention of the writer more than those of the minute anatomy, functions and diseases of the dental pulp. It might be conceived, from the title of this paper, that it was his intention to review the investigations made by himself and others in the structure and morbid conditions of this organ. Limitations of time exclude such an attempt. But while it is advisable to mention some facts alreadyknown, it is now necessary to bring modern knowledge to bear upon certain questions, and, by careful evidence and precise inference, to set forth in as concise a manner as possible some recent observations regarding it. These remarks refer to the dental pulp of man, in many respects unlike those found in the mammalian lower vertebrates. Comparison between the two, for instance, shows some dissimilarityin the anatomy of the bloodvascular systems, and the extent and distribution of the nervous apparatus. Omitting references to the teeth of fishes and reptiles, it should be noted that the pulps of the carnivora, herbivora, and rodents deviate considerably from that of man, and possibly of the anthropoid apes. These variations are not confined to anatomical characteristics only, but apply equallyto function.

(I)
(A) ITS HISTOLOGY.

Mesodermic in origin, and formerly incorrectly described as resembling the structure of Wharton's jelly, the pulp is a community of connective tissue elements which are embedded in a transparent and slightly granular basic substance, retained in a delicate reticulum, partly formed by the interlacing processes of the cells themselves, and partly bynumerous anastomosing independent connective tissue fibres, the peripheral parts of which bind the organ loosely to the dentine. Von Korff [1] especially studied these attaching fibres. I had previously noticed them, but did not emphasize their importance.

Section oj Odontology

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Occupying a cavity from which it is easily detached, the confines of which are composed of a unique calcifiedmaterial, the tissue may reasonably be remotely compared with marrow, or soft tissue in the larger and smaller medullary spaces of bone. When the apical foramen of dentine-the homologue and analogue of the nutrient foramen in bone-is formed, the pulp does not disappear but remains in situ, and one of its functions-the building up of primary dentine-ceases. There is no evidence that in normalcircumstances it continues to enclose itself in an ever-increasing thickness of dentine, but in nutritional and other disturbances this is a reaction which is
constantly in operation.

(B) ITS CELLS.
Of all the cellular elements the most remarkable are those units of what was originally designated the membrana eboris--interesting not only on account of their extraordinary morphology, but also because...