Page 28 - My FlipBook

PATHOLOGY OF THE HARD TISSUES OF THE TEETH.

Nomenclature.*
Atrophy. Hypoplasia. Contemporaneous accretional dys-
trophy. A deformity occurring along the lines of accretion, con-
temporaneously in all teeth in process of development during a
period of malnutrition. In this the enamel rods, the cementing
substance between the rods, and the dentin are all involved and
part of each is either imperfectly formed or wanting.
The enamel whorl. A deformity occurring within the
enamel, in which there is an abnormality of direction of the
enamel rods, usually associated with a pit in a surface that is
normally smooth.
Wrinkled or corrugated teeth. A deformity characterized
by abnormal ridges and grooves of the enamel surface, with
scalloping of the dento-enamel junction, and much disarrange-
ment of enamel rods. In each of these scallops there is a dis-
turbance of the direction of the enamel rods. They are thrown
into circles and whorls and not infrequently open cavities occur
in the tissue. The condition is comparatively rare.
White spots in the enamel. A deformity observed as a spot
which is paper white in the enamel; a form of dystrophy in
which the enamel rods are normally formed, but the cementing
substance which should occupy the spaces between the rods is
missing. These spots are not very frequent, and many of them
are passed over without observation. They are of little impor-
tance.
White enamel. A deformity similar to the white spots,
except that all of the enamel of the teeth is composed of rods
without the cementing substance, and the crowns of all of the
teeth are pure white. This is a very rare condition.
Mottled enamel. An endemic deformity, distinguished espe-
cially by the absence of the cementing substance between the
enamel rods in the outer fourth, more or less, of the enamel,
and presenting great variety of color. In certain regions of
comparatively few square miles, many thousands of persons
have this deformitv.

* Note.— Dr. Black wrote these paragraphs relative to the nomenclature of the
dystrophies of the enamel only a few weeks before his death. He was not then satis-
fied with the terms applied to the various dystrophies, and expressed his intention
to revise them before publication. He was especially anxious to find a simple term
to displace the terms atrophy and hypoplasia. In his last writing he used the term
contemporaneous accretional deformity, but realized that this was too long. It seems
best to retain the words atrophy and hypoplasia until a satisfactory substitute can be
found.