Periscope of Medical and General Science in their Relations to Dentistry. [Volume: 2, Issue: 9, April, 1861, pp. 513-522]

PERISCOPE OF MEDICAL AND GENERAL SCIENCE.

513

PERISCOPE OF MEDICAL AND GENERAL SCIENCE IN THEIR
RELATIONS TO DENTISTRY.
BY GEO. J. ZIEGLER, M.D.
Lecture on Dentition and its Derangemnents. By A. JACOBI, M.D.,
Professor of Infantile Pathology and Therapeutics in the New York
Medical College.
"The enamel of the teeth is subject to several anomalies. It may be
either defective or discolored. Its defective formation appears either in
excavations dispersed over the surface of the tooth, or there are complete
furrows or transversal notches around the crown of the tooth, the body
being still covered with, or entirely deprived of enamel. This atrophy is
the result of those severe diseases which the child may have been suffering
from during the development of the enamel. Acute exanthems are said
to produce the dispersed excavations; acute inflammatory diseases, the
furrows; and rachitis has often been observed to be the cause of the entire
absence of the enamel. The incisors of rachitic children are usually small,
appear late, and are very liable to become carious. Acute exanthems are
counted among the causes of this anomaly, especially by such writers as
classify the teeth with the dermal tissue. Small-pox is related to produce
isolated excavations which have a great similarity to the cicatrices remaining after small-pox. To vaccination also some have attributed the defective development of the enamel. Such children as were vaccinated
before any teeth appeared, or after their complete development, had finer
teeth than those who were vaccinated during their protrusion and growth.
"According to Prof. Nessel, the age can be determined in which a child
was affected with a severe disease, from the species of teeth affected, and
the distance from the top of the crown in which excavations or furrows are
found. If the incisors and the first molars are defective in enamel, the
disease ran its course between the twelfth and eighteenth months, whereas
a disease of the fourth or fifth year will leave its vestiges in the second
molars. The longer its duration, the broader the furrows. When disease
returns at different periods, there are often furrows at different heights.
Prof Nessel is of the opinion that this abnormal condition is the effect
of a severe disease, influencing as well the membrane outside the ivory,
from which the enamel is deposited, as any other part of the organism,
but does not depend on supposed abnormal acidity of the liquid contained
in the dental sac. For if this were the cause we should expect the enamel
to be defective all over below the line that was formed before the disease
occurred. Whichever may be the cause, the anomaly cannot be removed.
It would be aggravated by leveling the surface of the tooth, as extensive
caries would be the immediate consequence.
"Another anomaly of the enamel is its discoloration. Brownish spots
are the result of original development and composition. White spots are
sometimes the effects of mechanical injuries producing local disorganization of the enamel. They consist of carbonate of lime instead of the
phosphate and fluate, and from the fragility of the enamel at these places
are apt to give rise to carious degeneration.
"The anomalies described cannot be mistaken for those irregularities of
shape, such as furrows extending around a whole tooth, which are someVOL. ii.-37