When the artificial full denture be made for the purpose of reconstructing the lost function of patient's mastication and speech or his appearance, care must be taken of the fact that we are dealing with a living body which differs racially in topographic anatomical details. The author made the measurements on one hundred individuals of the various distances from the occlusal plane to each cusp of lower teeth and found that the occlusal plane established hypothetically by Dr. Gysi would be inapplicable for the Japanese jaws. The measurements showed that the lowest point in dental arch should fall on the contact point between the lower second bicuspid and first molar. It was also shown that the height of buccal cusp of second bicuspid came to the height of mucous rise at the glandula retro molare which is said to keep well its previous level even in edentulous jaw. In view of these findings the author think it advisable in arranging the artificial teeth that the disto-buccal cusp of extreme molar be posed at the same height with the posterior margin of trial base plate so as to keep the denture in the natural anatomical position and to reproduce in it the harmonious ralationship between cusps and tongue.

View full abstract

The oral examinations conducted on the 6, 396 children of 3 primary schools, revealed that the incidence of cheilosis was observed in 641 individuals (10, 024%), in which male children always prevailed in number than female. Bacteriological cultures taken from the angle of the mouth showed the presence of following types of bacteria ; Staphylococcus (aureus, albus) Streptococcus (α, β, γ, ) Diplococcus (Gram, +, -, ) Bacillus (Gram, +, -, ) Blastomyces. Of these organisms, Staphylococcus aureus were cultured in 59.34% from the lesions which failed to appear in the case of normal mouths examined. In view of these findings, Staphylococcus aureus should be recognized most significant as the causative organisms of the lesion.

View full abstract

The present work has been conducted first to identify the causative member of organisms responsible for the nitrite formation in saliva, and second to see the possible influences of several bacteriostatic agents upon these organisms. The results obtained tends to show that these nitrite producing organisms do not suffer any appreciable damage from those inhibitors, while other coexisting organisms seems to be more or less arrested. Bacteriological observations show that the organisms in question are penicillin resistant gram-negative rods which seem by prolonged impregnation in penicillin to stay in minute coccus-like forms for a while. In view of these facts these organisms will be logically termed as Bacillus coli. Whether the amounts of nitrite produced indicate accurately the proportional activity of B. coli or not is yet uncertain. More recently it was confirmed that the nitrite formed in saliva could be readily transformed probably to the more reduced substances and vanish away by the same organisms or by some other unidentified organisms. Hence it must be admitted that the nitrite formed by addition of the various agents do not always represent the total amount of reduced nitrate. These points in mind, further detailed studies are now in preparation.

View full abstract

It has been so far the most problematic in the studies of tartar of tooth how it happens to come into existence. The author, from this point of view, accompanied by the studies concerning the chemical components and morphological structure of the natural tartar in mouth, made a series of experiments in artficially grown tartar which hitherto none attempted. The author studied in particulars the morphological differences and similarities between the artificial tartars and natural one. First there are between them naturally a difference in age, that is to say, the artificial tartar grows in shorter lapse of 8 weeks, comparing to the natural one which usually needs far more longer period to grow up. Secondly there can be seen in the natural tartar a marked proliferation of moulds in the mouth which lacks in the case of the artificial one. As for the facts now they have in common, the whole body of both tartars had the porous and spongy structure whose sheleton being consisted of the organic substances in colloid. The author found that the view of the experimental tartar built up in sponge form had the close resemblance to that of the early stadium of the growing natural tartar in spite of lack of mould's proliferation. The author concluded therefore that the existence of moulds in the natural tartar is of secondary significance for its formation and that the building of spongy structure of organic colloid is rather the original ground for its formation. The organic substance in colloid have their source naturally in the constituents of saliva. The chemical examination of the saliva indicated that it is a solution in colloid, and from this points of view the author made several observations on its physico-chemical attitude. As it was observed that the air-bubble appeared spontaneously or could be readily set forth passively, the author reached to the idea that such colloid solution which is subject to Gibbs'law or Floatation principle must have the spongy structure in itself. In consistence with the idea, the author succeeded to note in microscopic examination the air bubble or froth in the natural as well as in the artificial tartar. It is then evident that the tartarbuilding has its orginating site in the colloidal sponge. The author proved that the colloidal substances in saliva can change its properties by the presence of lactic acid or ammonium produced in mouth, and moulds proliferating in caverns of tartar cause the deposit of calcium, hardening gradually the tartar body which is softer at the new-born stadium.

View full abstract

A male student of a high school, 17 years old, has suffered from epileptic convulsions and has taken daily 0.3 grams of Aleviatin (Sodium dilantin) for 2 years. He noticed some time ago a slight swelling on his gums. The swelling is due to Dilantin, although the grade is not so intense. Other causes of gingival hypertrophy were not certified. The excised gums were patho-histologically examined by routine method. Main findings were as follows ; 1. Light hyperkeratosis of mucous epithelium were seen, and moreover the deep intrusion of epithel-cord into proprial layer was characteristic. 2. Hyperplasia of connective tissues (chiefly collagene fibers), accompanying inflammatory granulation, was seen in propria. Intense perivascular infiltration of plasma-cells and lymphocytes, infiltration of the same cells in other parts of propria, slight exsudation and dilation of blood-vessels and lymphcanals were seen at the same time. 3. Tne findings of this case show a type of hyperplastic inflammation. And circulatory disturbances would have been beforehand with it.

View full abstract