Measurements were undertaken on a mixed population of Koshikizima, an isolated islet of Kagoshima Prefecture, which consisted of 456 males and 441 females ranging in age from 2 to 59. Data obtained were analyzed with respect to rate of age growth and sex difference. In additon, a comparison was made of these data among the neighboring inhabitants groups and the population groups of different races in neighboring countries. Results were summarized as follows. Difference with age I. Breadth of dental arch The value for the dental arch breadth in creased with age until 15 to 20 years of age, but it decreased slightly after these period. 2. Length of dental arch The value for the length increased with age until 11 to 15 years of age, but it decreased slightly after that stage. 3. Breadth of lower alveolar bone The maximum value for the breadth of lower alveolar bone was found in subjects in the twenties. 4. Dental arch index There was hardly difference with age in this point. Sex difference Male sudjects exceeded female in the magnitudes of the dental arch breadth of lower alveolar bone and length of dental arch respectively, but there was no appreciable sex difference with respect to the dental arch indices. Difference between the islander groups and neighboring inhabitant groups 1. Dental arch breadth In the dental arch breadth, the islander groups were inferior than the groups of Tanushimaru district with both sexes. The female islander groups were too inferior than the comparable groups of Beppu and Asoo districts in Ohita Prefecture. No appreciable difference was found between the islander groups of both sexes and the comparable groups in Kiuragi in Miyazaki Prefecture. 2. Dental arch length The islander groups of both sexes exceeded those district groups in Kiuragi of Miyazaki Prefecture, in Himeshima of Ohita Prefecture and in Hizi of Ohita Prefecture in the magnitude of dental arch length, but were inferior than the district groups of Asoo of Ohita Prefecture. 3. Breadth of lower alveolar bone The value in the islander groups of both sexes was smaller than that in the comparable group in Shimonoseki city, but when compared with the groups of Yawata city, the femle groups of islanders exceeded the comparable groups of Yawata city in this value. 4. Dental arch index The male groups of the islanders exceeded those groups in Tanushimaru (Fukuoka Prefecture), Himeshima (Ohita Prefecture) and Kiuragi (Miyazaki Prefecture) in this respect. The groups of the islanders showed values larger than those of Yawata female and smaller than those of Shimonoseki female. Difference between racial groups in the neighboring countries 1. Breadth of dental arch The Koshikizima islanders showed larger values than did Formosan but smaller values than did Mongolian and Korean. 2. Length of dental arch The islanders showed larger values than did Mongolian and Manchurian, smaller values than did Formosan and Korean. 3. Dental arch index The value of the indices in the islander groups was larger than those in the Mongorian, Korean and Manchurian race groups but smaller than in the Formosan group.

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A survey was conducted among populations of junior and senior high school pupils residing in Kitakyushu city on several envionmental factors that would affect the oral health status of younger people. The subjects were requested to fill in the quetionaire which was designed for analysis of possible correlations between factor such as preference of foods and other dietary habits and the health of gingiva and some of oral disturbances. The questionaionaire also demanded the subjects to answer about their habit of daily tooth brushing practice to know how much they were taught to care for their own oral health. The results were summarized as follows. I. Health Status of Gingiva An unagreeable sensation of oral cavity at the time of rising in the morning was complained by 26.6% of male subjects and 25.5% of female subjects. Bleeding from gingiva at the time of tooth brushing was experienced by 20.9% of male subjects and 22.7% of female subiects. Compacted food debris were seen in most of the subjects, but more freqently in the male. Pus formation was rarely reported. Cases of tooth mobility that were present in both senes decreased after about 14 years of age. Stippling of gigiva was seen in 28.1% of male subjects and 39.0% of female subjects. Very few cases of melanin deposition were reported. Dental calculus was reported from 17.7% of the male and 12.1% of the female. 2. Food Preference and Health of Gingiva Incidence of periodontosis was proved to rise in those subjects who preferred foods that were cooked either soft or served hot. The same was true with those subjects who preferred cooked fishes and sweetened foods 3. Tooth Brushing Habit Once a day practice was predominant among the subjects, and so was practice of tooth brushing before breakfast. The time spent for the practice seems to be decreased with advancing age of the subjects. Most of the subjects brushed teeth in both vertical and horizontal directions, and the lingual surface of teeth was brushed mostly in horizontal direction. A piece of tooth-brush was in use for 4 months in most of the subjects. Medium hardness of tooth brush with synthetic bristle was most frequently prefered and so was the shape of bristle with flat surface. 4. Number of Decayed Teeth and Foods Preference About one third of the subjects had not any knowledge about how many of their teeth had suffered dental decay. A majority of subjects had their teeth restored by fillings and other mean and the rate of such restorations increased slightly with increasing age of the subjects. Caries incidence was more frequent in those subjects of both sexes who preferred sweetened foods, acidic foods such as meat, fish and rice in general. The same was true in the male subjects who preferred alkaline foods such as fruit, vegetable and milk, and in the female who preferred hot foods.

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The dentin surface of human tooth crown was observed by means of scanning electron microscope and the following results were obtained. 1. Very clear picture of shallow depressions (foveola eburnea, Dentinfurche) showing fine network structure was obtained by lower magnification which demonstrated markedly different patterns in size and shape of respective depression according to the difference of tooth kinds used and sites of the crown observed. 2. By the use of higher magnification, not only came smaller depressions that subdivided each depression in sight, but also the presence of numerous pits that further subdivided the smaller depression and were presumed to be remnants of ameloblasts (Tomes' processes) was confirmed lying among complicated bundles of Ebner' fibrils.

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It is generally accepted that the wax pattern is considerably deformed by stress remained. But the degree of deformation is rather difficult to be determined. Therefore the authors discussed the specific volume change of inlay was as a measure of deformation using dilatometer. The results obtained were as follow : 1) The inner stress was considerably stored in the wax pattern cooled quickly from the high (60℃) to the low temperature (3℃). 2) The inner stress remained of the wax kept for a long time (5 hrs.) in the low temperature was emancipated perfectly and its specific volume became equal to that of the wax cooled very slowly. 3) The specific volume at 15℃ of the inlay wax cooled slowly was determined to be 1.0413cm^3/g.

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We reported a case of Cheilitis granulomatosa that had occured to a woman, 36 years old. The swelling of the right cheek decreased in seven days and the swelling of the lower lip began to decrease fourteen days after the extraction of the right lower first and second molars with paradontitis apicalis chronica. The swellings decreased mostly in thirty days after the extraction. A specimen taken from the lower lip showed chronic inframation. The patient today, a year and three months after the extraction, is alive and free of the disease.

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I encountered lately a Down's syndrome child with cleft of the primary and secondary palates. The boy of five months after birth, whose father was 31 years old, and mother 32, a primipara, has experimenced no stillbirth or abortion previously. In whole course of the pregnancy she denied using medicines such as cortison, thalidomide and anti cancer agent. Also she made denied of being sent out radial rays, specific infectious diseases such as syphilis or rubella, poisoning and shock of mind. Parents hadn't the intermarriage and denied the heredo-diathetic disorders. The infant showed 3300 gram in birth-weight, weighter than the mean birth-weight in same age. Oral findings observed were the right complete cleft lip-jaw-palate in addition to open mouth, macroglossia, fissured tongue. Beside these, epicanthus, hypertelorism, flat occiput, oblique palpebral fissures, hyperextensibility, hyperflexibility, transverse palmar crease, small ear, low nasal crista, widely flat root of the nose, otitis media, separation of the rectus were recognized. Chromosomal analysis of peripheral lymphocytes was performed by the Method of Moorhead et al. A result was G21-trisomy of the high frequency in Down's syndromes, that is, 47, XY, 21+(Chicago Conference).

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The authors experienced three cases of gingival hyperplasia caused by the margin of illfitting dentures. The patients were older women. In the first case, the mass of the gum was found on the incisal area of the upper jaw, in the second case, on the incisal area of the lower jaw and in the third case, on the molar area of the lower jaw. The masses, which consist of lobulated masses. formed one or multiple nodules in contact with the margin of dentures. We excised and removed these masses completly. Then we observed that the excised area in evry case was covered with normal oral mucosa. And finally, the patients were set with new dentures. After one year, the patients acknowledged that these was no recurrence on the same portion of gum and that the new dentures were very satsifactory. Such occurrence was predispose among older women. Histo-patholgical examination were performed on these masses. As a result, the masses in three cases were hyperplasiaof chronic productive inflammation withouttrue tumour.

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Clinical observation of the postoperative buccal cyst in 21 cases was made in the past three years. 1) In the clinincal and statistical observation of 21 cases on the patients age, affected side and duration, the results were almost as same as those heretofore reported. 2) The clinical and statistical observation of patients sex, the number of female was greater than that of male. 3) The subjective symptome was mostly pain and swelling of the face or oral region. 4) State when examined was mostly pain and swelling of the face or oral rgion. 5) Radiographic appearence was found no peculiar change, but radiograpic examination with a contrast medium revealed the outline of cyst, extent of cyst and enlargement direction of cyst. 6) Operation method was modified Caldwell-Lucs method in practice and operation wou nds were closed secondarily. 7) Operation findings : 1. Infection was observed in 7 out of 21 cases. 2. Maxillary sinus was observed in 13 out of 21 cases and it was compressed in upper outside in most cases. 3. Cysts of localized in maxillary sinus in more than a half of cases. 4. Lower nasal meatus counter opening was observed in 4 out of 21 cases, but it was closed 17 cases. 5. With regard to the relation between maxillary sinus and teeth, penetration of the root of tooth in to the maxillary sinus was found in 10 cases and the focus of the root apex was in contact with maxillary sinus at the basi-maxillary sinus or the cyst wall in the maxillary sinus in 3 cases.

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