For the purpose of measuring masticatory function by means of gravimetric sieveanalysis, it is important to study particle size distribution of masticated materials.
The number and size of screens, the number of masticatory strokes, and the quantity of materials have relation to the distribution of particle size, and give different results for measurement. Japanese rice, which is the most suitable test material, was selected, and the effect of these factors were investigated by changing oral conditions, employing 10-, 16-, 32-, 60-, 120-, and 200- mesh screens. Results summarized are as follows :
1) Particle size distribution is linear within standard error of 2%, when cumulative percentage oversize is plotted on the probability scale against the screen size on mathematical scale, in the following cases, namely complete dentition, molarsmissing, cases rectorated with crowns and bridges, and some cases of malocclusion, but such cases as full dentures and partial dentures don't give the linear correlation.
2) Inclination of this line (coefficient of regression) correlates with the percentage oversize by 10- mesh screen (r=0.9), and equation of regression is characteristic in accordance with oral conditions, therefore percentage oversize of each screen can be calculated from that of 10- mesh screen.
3) Particle size distribution is classified into 3 types, -denture-, normal-, and partial edenturous type, according to the coefficient of regression of this equation.
4) The correlation between percentage oversize of each screen and the number of masticatory strokes is formularized by y = e^-αt within standard error of 3%. “a, ” which iss constant, indicates chewing ability of each subject independent of the number of masticatory strokes (masticatory index) .
5) Abovementioned rules are found to be independent of the quantity of test materials from 1 g to 4 g. Masticatory index by the same screen size is inversely proportional to the masticated quantity of rice.
6) Masticatory efficiency is calculated by the ratio of masticatory index of each sub-ject to that of standard person, and it seems to be suitable unit to estimate masticating ability.
7) Masticatory efficiency by each screen size gives different value according to the type of particle size distribution. By denture type efficiency takes the lowest value at 16-mesh screen, by edenturous type at 10- mesh screen, and by normal type each screen size gives almost equal value.
8) The 10- mesh screen is most adequate to detect the rough difference of chewing ability of various oral conditions.

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The author has attempted in this experiment to compair, using Okada-Mimura's timemarking method with lead acetate injection, the effects of the grafts of formalin-preserved bone and of fresh bone.
The operative procedure consisted of bridging a graft between both sides of the mandibulae of forty adult rabbits ; the grafts measured about 15 mm.
The animals were sacrificed at one to eighteen months. In no case was there any chance that the grafts were lost because of infection.
There was no evidence from these experiments that any of the bone elements of fresh autogenous transplant lived or retained osteogenetic power.
The author has demonstrated that the new bone formation was totally a function of the host tissue, and ultimately the grafts were replaced by newly formed bone from the host tissues.
In the new bone formations, autogenous bone grafts were superior to fresh homogenous bone grafts and preserved bone grafts. But there were no differences between fresh homogenous and preserved bone grafts.
The formalin-preserved bone grafts were inferior to fresh bone grafts only in the fixation and replacement in early phases of healing.
It appeared that the process of resorption of the preserved bone grafts was slower than that of the fresh grafts. It seems that the resorption of the preserved bone grafts was a function of newly formed bone marrow.
All of the grafts induced the growth of the new bone. The vinyl resin also induced the growth of the newly formed bone.
There was no difference between the formalin preserved and fresh bone grafts in the essential mechanism of the process of bone transplantation.

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A 16-year-old girl, whose parents consanguineously married, visited us suffering from congenital dystrophic bullous epidermolysis.
Her oral findings corresponded with those described in care of dystrophic type. Many small tubercles were noticed over the palatal mucosa and their patho-histological findings bear complete resemblance to vesicles spreading over the skin.

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A woman, aged 76, suspected of so-called Plummer-Vinson syndrome is presented. All the symptoms have become better after 3-month peroral administration of iron and vitamin preparation.

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We made, for the purpose of surface anesthesia of the oral mucous membrane, six kinds of anesthetics from 10% solution of anaesthesin in Propylene glycol.
Then these anethetics were closely examined by Katsuki's method and thereafter clinical use was attempted.
In his study, the best result was obtained when a 10% solution of Anaesthesin was mixed with 1 volume per cent Triton (Alkyl-Alyl-Polyether-Alkohol) in the solution abovementioned, adding 2000 units Sprase (Hyaluronidase) .

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