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

514

THE DENTAL COSMOS.

times observed as family peculiarities. Such teeth are generally hard and
solid; have very little tendency to become carious or wear prematurely,
and differ widely from those soft and friable teeth which are due to the
arrest of development in early infancy, by either hereditary disposition, or
accidentally contracted severe disease, or protracted malnutrition.
" To Mr. Hutchinson, of London, the profession is indebted for a number
of good observations on the influence of hereditary syphilis on the development of the teeth. Although the majority of his remarks relate to the
permanent teeth, in which this hereditary malady exhibits itself best, there
are some morbid symptoms in the temporary teeth belonging to this class.
The temporary teeth, in hereditary syphilis, do not present any peculiarities of form; they are, however, often of bad color, and are very liable to
early decay. The central upper incisors are the first to suffer from caries,
and often crumble away under its influence, within a year of their being
cut. The upper lateral incisors soon follow, but the canines very rarely
indeed. The caries generally attacks the neck of the tooth, and rapidly
penetrates through it, causing the crown to crumble away, soon after which
the fang falls out. Children who have suffered severely from syphilitic
stomatitis, are often toothless as regards the whole of the upper incisors,
from the second year till the permanent set are cut. Occasionally, the
lower incisors suffer in the same way, but far more seldom than the upper
ones. The deciduous canines rarely either become carious or drop out.
They are, however, liable to a curious kind of circular wearing away, a
sort of tusk or peg remaining in the centre of each tooth; the process
of circular attrition having commenced a little above the level of the
dental neck. This condition Mr. Hutchinson has seen in but five or six
cases, and in all these it was symmetrical on both sides, and in both upper
and lower sets; he has never yet seen it excepting in syphilitic children.
It is not usually produced in any very morbid degree until about the age
of six or eight years. He has met with an approach to it in one of the
molar teeth of a syphilitic child. The outer layer must, at least, be of a
peculiar and abnormal softness to be worn away so singularly.
"Original disposition is not an uncommon cause of the enamel being
deposited in a thin transparent layer only. The children in whom it
occurs are usually of weak and feeble constitution, and particularly defective as to the development of their osseous system in general. Transparency of teeth according to Rudolph, and bluish-white color according
to Duval, are symptoms of rachitis; semi-transparency, as of horn, of herpetic predisposition; semi-transparency and milk-white color, of scrofula
and tubercles; yellow and white spots, intermingled, with derangement of
general development; small, white, yellow, or brown spots, of commencing
caries. Yellowish-white color, and average darkness, are found in the
most durable and solid teeth.
" There is one agent, the influence of which appears to be particularly
dangerous. I allude to sugar. It has long been considered by physicians
and the public as the cause of many cases of caries of the teeth. Its
tendency to be transformed into acid is well known. Every acid is liable
to disorganize the enamel of the teeth. It is proven by direct experiments
that sugar dissolved in water, and exposed to a certain temperature and a
continued afflux of atmospheric air, would not disorganize enamel, although
this were kept in the solution for many weeks after the transformation of
sugar into acid has taken place. There is, however, a difference in the
transposition of sugar, according to whether it takes place in a tumbler or
on the teeth. The change is more rapid on the teeth than otherwise, from