Although much evidence is available which has established positive correlation between one's tooth health status and his physique, there seems to be no adequate information as to possible correlation between one's tooth replacement and his physical capacities as direct function of his physique. Physical examinations have been carried out on a total of 2140 subjects of both sexes ranging in age from 6 to 14 years, all residing in Miyakonojyo city in Miyazaki prefecture, with regard to their physique (body height, body weight and chest girth) and their physical capacities as measured by 50-meter-running, standing broad jumping and soft ball pitching. On the basis of the means and standard deviations obtained from the examinations, the subjects of each sex and age group were divided into three grades groups of which A group representing the value of mean+standard deviation, B group mean±standard deviation and C group mean-standard deviation and to each of these groups were respectively allotted the examination mark of +one point, zero point and-one point. The sums of the points obtained for physique, physical capacities were respectively called the physique and physical capacities points and the sum of the latter two was called theit composite point. Correlations existing between individual's tooth status including the tooth replacement and tooth decay and his physique and physical capacities were studied in every groups for every items examined, and the results obtained were summarized as follows. 1) It was revealed that those subjects having excellent marks in the physique and physical capacities, in the physique and physical capacities points and in the composite points, had fewer number of existing deciduous teeth and greater number of erupted permanent teeth, suggesting that the tooth replacement had close relation with the development of general physique and physical capacities. 2) Study on the correlation between the incidence of tooth decay as examined on the basis of df +DMF and C_3+M and the physique, physical capacities, physique and physical capacities points and the composite points in A and C groups revealed that C_3+M was greater than df+DMF, suggesting that those having greater number of tooth decay had inferior physique and physical capacities. It was concluded that the tooth decay, especially that represented by C_3 and M had close correlation with individual's physique and physical capacities in the school age population under rapid physical development.

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During the course of treatment of the root canal infection of left upper central and lateral incisors on which resin veneer gold crowns were set, we have observed that the resin was suffering expansion from some chemical change. The present report concerns with the clinical observation as well as the laboratory experiment on the solubility of resin material by various medical agents routinely used in the dental clinic. The summary is as follows. 1) A case of resin expansion was observed in which formalin-tricresol acted as the chief agent for the expansion. 2) Tricresol, formalin-tricresol, carbol, campho-phenique, modified phenol, thymol alcohol, creosote, eugenol, xylol and chloroform definitely dissolved the resin. 3) The patterns in which the resin was dissolved by the various agents could be classified into 3 types : in the first type the resin was dissolved following expansion, in the second type it was broken down into small pieces, and in the third type disintegration and expansion of the resin took place simultaneously.

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Lead contens have been determined coloimetrically by the dithizone method on the dental calculi taken from the mouth of seven subjects who were daily exposed to lead materials in the printing bureau of a newspaper office. The results were summarized as follows. 1) The dental calculi used in this study ranged from 15.1 to 57.0 mg in weight. 2) The light transparency of the dental calculi ranged from 57 to 87 per cent. 3) The lead content of the materials ranged from 9 to 833 gamma per gram, all exceeding values of lead content reported by previous authors for the human tooth, bones, blood and gingiva. 4) In view of the great amount of lead found in dental calculi, frequent scaling and oral prophylaxis should be recommended for the persons concerned. It was also concluded that determination of the lead content in dental calculi would make one of the important measures for the early detection and prevention of the systemic lead poisoning in these people.

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Using the photographic method, localization of the center of gravity in lower tooth was studied. These teeth were composed of each 10 pieces of central incisors, canine, first premolar and first molar. The center of gravity in tooth was located in the crown side from the middle of the tooth length, and the position of the center corresponded to the vicinity slightly above or below the cervical line on the labial and buccal sides of the tooth.

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Ethnological study on the physical traits of mouth in the inhabitants of north-eastern section of Kyushu is as yet unavailable. An inhabitants group of Asao, Yokkaichi-machi, Usa-gun, Ohita Prefecture, was therefore, selected as the representative of inhabitants of north-eastern Kyushu, and various oral traits in these people were compared with those found in the easterner (inhabitants of Toyooka, Hiji-machi, Hayami-gun, Ohita Prefecture), southerner (inhabitants of Takajo, Miyakonojo City, Miyazaki Prefecture) and in the inhabitants of a isolated isle of north-eastern Kyushu (Himesima, Higashikunisaki-gun, Ohita Prefecture). The data obtained were assessed from ethnological view point, and were summarized as follows. 1) The oral traits in the north-eastern inhabitants had generally close resemblance to those of the easterner rather than to those of the southerner and the north-eastern islander. 2) Of all the oral traits in the north-easterner, the most significant were the mesiodistal crown gradient, torsion degree of the teeth, length of dental arch, circumscribing length of dental arch, posterior palatal height, length of palatal arch in the molar region and the width of palate. 3) The mesio-distal crown gradient in the inhabitants of north-eastern Kyushu was greater than any of those found in the Korean, Manchurian and Formosan ; the torsion degree was greater than the ones in the male inhabitants of northern Kyushu and the male Manchurian ; the circumscribing length, posterior palaatal height in the female, and the length of palatal arch and width of palate, both in the molar region were respectively greater than those found in the easterner, southerner and the north-eastern islander.

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