941
ABSTRACTS OF CURRENT LITERATURE
ORAL PATHOLOGY Case
Report
of
Tooth
Substance
Barnes.
Am. J. Orthodontics
Completely
Developed
About
a Foreign
Body.
R. E.
36: 215, March, 1950.
A case is reported in which the patient at the age of 7 years had fractures of the mandible in two places, between the lower left lateral incisor and canine, and between the crowns of the forming premolars. To hold the fragments together, the mandible had been wired with silver wire, 0.050 inches in diameter, Recovery was uneventful. The patient was seen by the author at the age of 15 years. The mandibular second
premolar
had failed
to erupt.
X-ray
examination
revealed
the fact
left
that the silver
wire had been passed through the area of the developing second premolar tooth. The case was treated as one of usual impaction and appliances were constructed to make space for the impacted premolar. The tooth failed to respond to treatment, and it. was felt that the silver wire had passed through the root of the tooth and prevented eruption. The wire was removed and the tooth brought into position. The author feels that this case proves that tooth structure can grow about
a foreign
body. T. J. C. Recherches sur las structure Dentine.) B. KBrBbel. Favorable light
sections
have permitted
method
allows
of
de la dentine humaine. (Research on the Structure Schweiz. Monatschr. f. Zahnh. 59: 633, 1949. teeth
and a simple
the observance
proving
method
of a definite
the existence
of
dentine
of examining
reticular
structure
canaliculi
of Human
them by traversing of the dentine.
and the fibers
of
Tomes,
The and
explaining them. The dentine prisms show in transverse and oblique sections, and the canaliculi and fiber,s of Tomes can be distinguished. The center of the prisms is mineralized and can be called
the calcified
intercanalicular
prisms lies in their direction
substance.
The difference
between
enamel and dentine
and their structure. R. R. B.
Ueber
vergleichende SchB;delmatepti.
Untersuchungen iiber die (Comparative Investigations
Skull Material.)
0. Brinch
Kariesvorkommen an archaalogischem on Caries Frequence in Archaeological
and V. Mfiller-Christensen.
Schweiz.
Monatschr.
f. Zahnh.
59: 882, 1949. Former
investigations
on the caries
frequency
of the last thomand
years have been
proved to be of very little value because of defective material and loss of many teeth by The material which forms the basis for this paper careless exhumation and transport. was found during most careful and exact excavations of the convent of Aebelholt near Copenhagen, Denmark, where burying rights went back as far as 1180. Meller-Christensen conducted
the exhutiations
from
1941 to 1947.
Five
indices
were given for the judgment
of scientific value attributed to the skull material found: (a) an archaeological index, i.e., percentage of teeth present as compared to the number of teeth present in viva; (b) the comparative dental index, percentage of erupted teeth present compared to 32 as 100 per cent; (c) the pathologic dental index, percentage of teeth lost in vivo as compared to 32 as the optimum; (d) the total dental index, percentage of erupted and unerupted teeth present as compared to the number of teeth present in vivo as 100 per cent; (e) the age index, which gives the average age of the investigated skull material. Out of 756 skeletons exhumed, 197 skulls were in perfect condition, and of the rest, 373 skulls in defective Caries frequency of
the
defective
condition were inve.fltigated. is closely related to the loss of the teeth in vivo.
skulls
caries
was
found,
whereas
the
carie’s frequency
In 42.5 per cent of
the perfect
942
QUARTERLY
REVIEW
OF
LITERATURE
The caries frequency of the teeth was 5.4 per cent for the material was 54.8 per cent. defective material, and 5.9 per cent for the perfect material. Many mandibles of the mature and senile type have shown as many as 16 teeth. A close study of the tables which are the result of the investigation is nece’ssary for a good understanding of the latter. Caries, seen through the ages, reached its first peak during the Roman reign, was lowest in the Middle Ages, and has risen to a universal disease in the nineteenth century and our times. R. H. R. “Black-Stain.”
C. Leimgruber.
Schweiz.
Monatschr.
f. Zahnh.
60:
124,
1950.
It is a brownish-black pigment belonging to Black stain is mostly seen in children. the class of melanin pigments and is observed forming along the gingival line of the teeth in relatively caries-resistant individuals. It has been establiahed that its colorless, basic substance is normally secreted by the salivary glands of epithelial origin. Furthermore, the pigment is a substance derived from the “maturation factor” by polymerization and oxidation. The maturation factor determines the resistance of the hard tissues of the teeth and is itself dependent on the formation of its components in blood and saliva. The synthesis of the maturation factor, however, must not exceed a certain measure above Thus, black stain is an inactive form of the maturation which it loses its biologic qualities. It has been shown that it can be kept in its active form by the addition of small factor. quantities of fluorine or of salts of oxalic acid. The result of the experiences proves the existence of the maturation factor; the visible proof is black stain and its importance regarding resistance to caries seems to be well established. Regarding fluorine prophylaxis, the author stresses his claim that fluorine does not transform hydroxyapatite into fluorapatite, but only- scarves to maintain the maturation factor in its active form, and to prevent its inactivation into black stain, and therefore has a purely catalytic action. R. H. B.
Zur Symptomatologie und Differentialdiagnose des Rankenangioma der ange. (Symptomatology and Diagnosis of the Angioma Racemosum of the Cheek,) A. Becker. Ztschr. f. Laryng.,
Rhin.,
Otol.
10: 498, October,
1949.
Angioma racemosum, which are frequently observed in the region of the head, do not belong to the true neoplasms. They are generally due to a fault in development producing a vessel hypertrophy. Resulting fibrosis causing a mass in which occasionally stones, so-called phleboliths, are found. In the case described by the author the region of the angle of the jaw was involved. The swelling was the size of a plum, elastic, and movable under the skin. On palpation three lentil-sized concretions could be felt which also were visible in the roentgen film. When eating, the swelling increased distinctly, only to regain its normal size after mastication of foods. The ducts of the salivary glands appeared normal. Histologic examination revealed a ball of veins with very thin walls, and thickwalled arteries. Some thrombi contained in the former showed complete calcification. The increase in the size of the swelling during eating of food was due to an increased blood supply during mastication with a stasis occurring in the veins. Treatment consists either of tying off the afferent vessels, or excision. E. P. S.
Ueber persistierende zahnLrzt1.
Ztschr.
Milch&i.hne.
(Persistent
Deciduous
Teeth.)
H.
Harnisch.
are
still obscure. The irritation caused by
Deutsche
5: 120, 1950.
The causative factors of the resorption pressure exerted by the growing permanent
of deciduous teeth teeth, the resorptice