From the references on the spontaneous occurrence of pleomorphic forms. in oral Lactobacilli, it was survayed that rod, coccoid, filamentous and crumpled forms were the major category of the classification of numerous dissociation in morphology. The morphological changes of L. acid. Harrison 3 A which grows normally rod was observed under the condition of the media containing sublethal dosis of common chemicals, Penicillinr Sublimate, Aureomycin, Acrinol, Homosulfamin, Urea and also under the pepton deficient media, and eventually it was approved to respond these given circumstances to rise filamentous, swollen, crumpled, coccoid forms. Judging from further cytological investigation, it was highly probable to consider that the resulted pleomorphism were by inhibition or disturbance of physiological process of cell function which was, in bacteriological cytology to be analysed to cell division, cell wall formation, divïsion of chromatinic body, cytoplasmic reproduction. In general, Lactobacilli belongs to rather sensitive genus against a little change in circumstance. Eventhough the media seemed to be normal for us, spontaneous pleomorphismm of oral strains on it, therefore, might be caused by unknown factors under which they were hard to maintain their healthy life, to be similltr to the harmful action of chemicals above.

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Odontological measurement on the identical twins with complete hare lip of the right side was made. The data indicate that there were many resemblance between them. The heredity of this case was also discussed.

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When homosulf amine was used through root canal therapy, it has been known that the germicidal effect was reduced by anti-agents produced in the root canals. Among these anti-agents were necrotic tissues, pus, secretion and blood etc. In this experiment, therefore, it was tested how these unfavorable agents worked in vitro upon the germicidall effect of this medicine.
The chief results of this research are as follows:
1) Without anti-agents, the local use of 5% homosulfamine solution would be considered most effective in vitro.
2) By consideration of the time of 50% LD. of all amount of bacteria, the effect of 20% homosulfamine solution was remarkably reduced by pus only to show that of 5% solution.
3) 5% Homosulfamine solution was reduced by secretion or gelatine to 1.25% solution in the effect.
4) No change caused by serum was observed.
5) By using urea with homosulfamine, the reduction of the effect by pus could be abated.

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Eight quantitative measurements, i. e. six heights and two widths, were measured by means of Martin's Gleitzirkel on the zone of the mouth—the part of the face below horizontal plane at subnasale and thus eight indices were obtained.
Materials used were 4511 normal healthy boys and girls in the city of Kawasaki.
According to Ogawara's classifiaction, these indices were classified from 1 to 6 and were arranged in the order of I, II, III, A, B, C, SMUG which were named “Formula of the zone of the mouth”. Both investigation of morphological changes of the formula of the zone of the mouth with the advance of development and observation of lateral views of cutaneous and mucous areas of the lip were made with interesting results.

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In order to make the former system Nakazawa's (1944) more rational for the convenience of practical application, our reformed and developed, system of classifying partial dentures was advocated and while on this subject the statistical survey of partial dentures following this new classification was investigated. The former classification was mainly based upon the position of the remaining teeth, but we have found it difficult to classify some cases when we depend upon this old system of classification and have attempted to subdivide in further detailed steps.
In the former paper, Nakazawa has classified the partial dentures from following foundation.
I. From the teeth restorated with denture:
A. Dentures restorating incisors and cuspids (Anterior teeth-Denture) shown in Fig. 1, 2
B. Dentures restorating bicuspids and molares (Posterior teeth-Denture) Fig. 3, 4, 5
C. Combined type of dentures A and B (Anterior and Posterior teeth-Denture) Fig. 11, 12, 13
II. In accordance with the condition of the edentulous ridge, opened or closed, the above classified “Posterior teeth-Denture” are divided respectively into:
a. Dentures attached only anterior (free-end) Fig. 3, 4, 11, 12
b. Dentures attached both anterior and posterior (intermediate) Fig. 5, 7, 13, 15
c. Combined type of a and b (combinated) Fig. 8, 9, 17, 18
III. In accordance with whether the edentulous ridge is beyond the median sagittal line or not, “Posterior teeth-Denture ” and “Anterior and Posterior teeth-Denture” are further divided respectively into:
a' unilateral Fig. 5, 8, 13, 17
b' bilateral Fig. 4, 7, 16, 18
Moreover, as you see, it is probable that an edentulous space may be intersected by the existence of the remaining teeth in two or more parts of space. On that occasion a set of “bilateral free-end denture” must be differentiated from the bilateral continuous free-end denture. Accordingly, we further subdivide the above classified dentures from. whether the edentulous space involves remaining teeth or not.
5, 000 partial dentures constructed by the members of the infirmary attached to our school from April 1950 to March 1953 were statistically investigated. We have obtained the following results.
1. The percentages of “Anterior teeth-Dentures” are 11.8%, “Posterior teeth-Dentures” 47.0%, “Anterior and Posterior teeth-Dentures” 41.1%.
2. As for the “Posterior teeth-Dentures”, “free-end-dentures” (19.3%) and “intermediate-dentures” (20.60) are comparatively numerous than others, and. “combination-dentures” (7.1%) are less than others. Among “free-endden tures ”, “bilateral-free-end-dentures” (11.9%) and among “intermediate-dentures” “unilateral-intermediate-dentures” (17.8%) are distinctively more than others.
3. As for “Anterior and Posterior teeth-Dentures”, “combination-dentures” show-the greater percentage of 19.9%, while “free-end-dentures” 12.6%, and “intermediate-dentures” 8.7%.
4. The denture for the lower are more than that for the upper. The percentages of “Anterior teeth-Dentures” for the upper, and that of “free-end-posterior teeth-dentures” for the lower are high rate than that for lower or upper.
5. A comparatively few number of “bilateral-intermediate-posterior teeth-dentures”, “unilateral-combination-posterior teeth-dentures”, “unilateral-free-end-anterior and posterior teeth-dentures ”, “unilateral-intermediate-anterior and posterior teeth-dentures ”, and “unilateral-combination-anterior and posterior teeth-dentures” are not so important from the statistical point of view, but have much to note from the practical point of application,

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1. From the present study of the histological investigation of 34 human embryos the 4 th week-the end of 4 th month of development stage, it seems to be rather doubtful that the reduction of dental lamina and the penetration of vessels into enamel organ are to the largest extent achieved by the mesenchymal cells, as hitherto believed.
2. In the earlier stage of tooth germ formation, ectoderm cells have the latent potency of mesenchyme.
3. The ectoderm cells are able to differentiate into the erythrocytes ; that is, the latter in the dental lamina and the enamel organ has its origin in the former.

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In order to make a detailed observation of the radiograms in case of the jaw tumor, 31 specimens of surgically removed mandibles were x-rayed by the factors of 20 mA at 60 kv, 4 sec, 1 m focus-surface distance, and 0.5 mm. Al filtration without screen.
Materials used were 15 cases of carcinoma, 11 of enamelblastoma, 3 of sarcoma and 2 of fibromyxoma, each of which showed its characteristic radiographic finding.

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Statistics obtained from the clinical observation of the supernumerary teeth and the congenital absence of teeth, based on the examination of our clinic are as follows :
(A) On the supernumerary teeth.
(1) The frequency of the supernumerary teeth was in 0.8% of the patients, giving a little higher degree in male than in female.
(2) Those accurrence was predominantly frequent in the anterior and premolar teeth, above all in the upper jaw.
(3) As for the state of eruption, 12 teeth (85.7%) erupted and only 2 teeth (14.3%) remained without eruption.
(4) Most of the supernumerary teeth were of rudimentary form.
(5) The abnormal displacement of the neighbouring teeth which is due to the supernumerary teeth was observed in as high as 54%.
(6) As for the combination of the other diseases, harelip and cleft palate was seen in 2 cases and schizophrenia in one case of all the eleven cases.
(B) On the congenital absence of teeth.
(1) The congenital absence of teeth was discovered in 1.44% of the patients, The occuring frequency was two times higher in female than in male.
(2) The congenital absence of teeth was seen most frequency in the anterior and premolar regio, showing little difference between upper and lower jaw as well as between right and left and it was discovered in female more than in male.
(3) 76.2 of the patients has 1 tooth missed, 9.6% 2 or 3 teeth, 4.8% 4 teeth missed.
(4) The effect on the neighbouring teeth was seen in as high as 95.2%.
(5) As for the combination of the other diseases the short frenulum linguae was discovered in only 2 cases of 21.

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A 14-year-old boy visited us, complaining of bilateral nasal obstruction particularly on the left side. A swelling of small-finger tip size was noticed at the basis of nasal sep-tum in the vestibule on the right side and a part of a tooth was exposed outside the swel-ling. The tooth and its surrounding tissue were surgically removed.
From the findings of operation it could be considered that the tooth is a supernumerary mesiodens and the surrounding tissue is granulation caused by chronic irritation of the nasal secretion.

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A 20-year-old man visited us, complaining of a swelling of the floor of the mouth, . which had caused him a strange feeling since his childhood, but had been left alone on account of no subjective symptoms and other troubles. From the clinical standpoint it apparently showed an appearance of dermoid cyst partly associated with a finding of ranula, . while biopsy revealed that it was not a typical type of ranula, showing ciliated epithelium over the internal surface of the cyst wall.
As a conclusion, it may be considered to be a cyst related to a duct of Bochdaleck's gland.

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Usualy, on the treatment of infected root canal the suck and flush apparatus devised from S. Seidner is used. But Seidner's apparatus is complexity and difficulty to disinfect and its management in oral cavity is not convenient. Then the authors improved his apparatus. As a result of simplification, the apparatus was became easily to manage and disinfect. Good results were obtaine3 by clinical application.

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