Dental Excavators. [Volume: 2, Issue: 1, August, 1860, pp. 10-14]

10

THE DENTAL COSMOS.

the inferior maxillary, their thickness being even less. It will also be seen
later that, during ossification, the dental groove is developed by a method
of ossification similar to that by which the groove of the inferior maxillary is produced, and that this groove exists before the appearance of the
dental bulbs.*
The union of the soft parts of each half of the palate with each other,
and with those of the median partition of the nasal fossae at the mesial
line, occurs before the appearance of the dental follicles. It takes place,
as we have already stated, near the 60th day. It is really in the ninth
week that the mouth is formed by the occlusion of the nasal fosspe above
the tongue. It is also to be remarked that at the time when the follicles
appear in the upper jaw, the corresponding lip already exists, like a narrow fold with a thin edge.
(To be continued.)
DENTAL EXCAVATORS.
BY D. H. GOODWILLIE, D.D.S.
IN the operation of filling teeth there are several things of the very
first importance, not only in regard to the operators themselves, but also
in a certain degree to those operated upon. The time needlessly occupied
in the operation of filling is of some importance to both,-and any way
by which we could arrive at the required results with expedition should
receive attention from the profession. The time and efficiency necessary to arrive at the desired point we are endeavoring to reach, depend very materially upon the instruments used in an operation. As
the excavators are the first instruments that come into our hands for the
highly useful operation of filling teeth, I will endeavor to arrange them in
a systematic manner, and to throw out some ideas which I hope may be
useful, at least to some who may be setting out in professional life; and
last but not least, to give the manufacturers a proper idea of what such
* According to M. Guillot, "these primitive traces (those of the teeth) originate
at the same time as the first traces of the bone, before the muscles, nerves, and
blood-vessels can be distinguished in the different parts of the face." And again: "The
dental spheroids really appear first, the bones after them; the mucous membrane
and the periosteum belong to secondary creation."-(N. Guillot, Recherches sur la
genese et 'evolution des dents et des machoires; Annales des Sciences naturelles,
Paris, 1859, 8vo., vol. ix. pp. 288, 289, 310.) Dissections upon the fresh foetus, and
not upon preserved pieces reduced to thin cuts, and the microscopic examination of
fresh preparations, make it easy to prove that this opinion is erroneous. The vessels, nerves, bones, and many muscles of the jaws are already developed, and easily
seen by transparency, or even readily dissected, previous to the time of the appearance of the dental follicles. The following paragraph will demonstrate the exactitude of the latter facts, which have been long known elsewhere.