This study was undertaken to examine the avoidance phenomenon of permanent tooth germs caused by the periapical inflammation of deciduous teeth in children. The orthopantomograms of 32 children (2 to 9 years of age) without caries and 74children (3 to 9 years of age) with periapical inflammation of deciduous teeth were used as materials for the investigation.
The results were as follows:
1. The average of the difference between right and left sides measured in three locations of first mandibular premolar tooth germs of 32 children without caries was mesio-distally within the range of 1.16 to 1.34 mm and vertically within the range of 0.50 to 0.63 mm.
2. The average of the difference between right and left sides of second mandibular premolar tooth germs was mesio-distally within the range of 1.08 to 1.31 mm and vertically within the range of 0.62 to 0.86 mm.
3. The avoidance of permanent tooth germs caused by the periapical inflammation of deciduous teeth was found in 19 of 74 teeth (25.7%). Concerning the region of the teeth, avoidance was found in 6 of 38 teeth in first premolar (15.8%), in 13 of 36 teeth in second premolar (36.1 %).
4. The avoidance of permanent tooth germs was frequently found in children ranging from 4 to 7 years of age.
5. Avoidance was observed in those cases that the size of the radiolucency of periapical lesion was more than 10 mm in width or length.
6. Avoidance was frequently observed in the stage of the crown formation of permanent tooth germs.

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On the basis of the dietary records of 100 infants (61 boys and 39 girls) at the age of one and a half years, the intake of energy, protein, milk, and between-meal snacks, and the sense of taste were surveyed.
The results obtained were as follows:
1. The daily intake of energy and protein were 947±205 kcal and 37.5±10.7 g in the boys, and 908±155 kcal and 35.0±9.1 g in the girls. The amount of energy was lower and the amount of protein was higher than the recommended intake.
2. The daily intake of milk was 217±196 ml which was within the recommended limits of 200-400 ml. However,28% of the infants had no milk, and 36% had fewer than 200 ml.
3. The ratio of energy from between-meal snacks to daily total energy was high (boys: 26.4%; girls: 30.9%). Because the between-meal snacks of infants at the age of one and a half years is important as a supplementary nourishment, we have to view their food habits and nutrient intakes comprehensively.
4. As between-meal snacks, fruits, milk, juice on the market, drinks containing lactobacilli, biscuits, cookies, custured pudding, potato chips, ice cream etc. were eaten frequently.
5. 41% of the infants ate between-meal snacks, irregularly.
6. Infants liked noodles, fish, tofu (bean curd), fruit and laver sea weed etc., and disliked eggs, meat, vegetables, fish and cheese etc. + It was considered that the sense of taste of the infant at the age of one and a half years was relatively impartial.

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For the purpose of evaluating the characteristics of a pit and fissure sealant called Teethmate (Kuraray Co. ), we examined the polymerizing time, the flow and the weight of the drop from bottle and compared these characteristics of Teethmate with those of White Sealant and Delton. Also, in order to discover the influence of Teethmate on the oral mucosa and gingiva as well as the state of the retention on the pit and fissure, we conducted a one month clinical test and observation on 19 patients who visited the clinic of the Osaka Dental University, Department of pedodontics. A total of 39 upper and lower permanent molars were examined and the following results were obtained.
1. Concerning the flow of the resin, Delton revealed the best results with Teethmate showing a level of flow between those of Delton and White Sealant. It was assumed that the difference in the flow was based on the viscosity level of the resin.
2. The polymerizing time was the same for all three types. Compared with the 60seconds polymerizing starting time of Delton, White Sealant showed a somewhat faster tendency and Teethmate showed a somewhat slower tendency.
3. As for the weight of the drop from the bottle, that of Teethmate was the same as that of Delton. However, with White Sealant the weight of the universal liquid tended to be greater while conversely with Teethmate the weight of the catalyst tended to be larger.
4. The results of one month of clinical observation showed that there were absolutely no harmful effects on the oral mucosa, gingiva or pulp.
5. Among the 39 Upper and lower permanent molars which were sealed, complete retention was achieved in 33 cases, while loss of sealing occured in 4 cases at the buccal groove and marginal fracture occured in 2 cases. The ratio of complete retention was 85%. The ratio of complete retention when considering only occlusal pit and fissure was 95%.
Based on the above findings, the pit and fissure sealant Teethmate was felt to be sufficiently effective as a sealing material for clinical use. Also, as the working time is comparatively long, and the polymerizing time is short, together with the fact that the coloring is a transparant light rose color, the sealing procedure and examination can be easilyconducted.

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The process of the eruption of permanent mandibular anterior teeth was observed overall with the use of radiographs. The materials were the serial panoramic tomograms obtained from 85 children ranging from the deciduous dentition stage to the mixed dentition stage.
Before measuring them, a preliminary study was made by using the dry skull, and the reproducibillity of the images on the panoramic tomogram was confirmed.
The results were as follows
1) The chronologic change of the amount of tooth germ formation and rate of eruption of the central incisor, lateral incisor and cuspid showed a curve using a cubic regression equation with the chronological age as an independent variable in both boys and girls. Based on, it is suggested that the growth change of the permanent mandibular anterior teeth is not constant in the course of development. Even though the cuvic regression curves of the central and lateral incisors showed similar shapes, the age of the growth spurt of the central incisor occured about one year later than that of the lateral. The rate of eruption of the lateral incisor and cuspid in girls showed a significantly higher rate than in boys.
2) The extent of overlap among the four incisor germs showed a tendency to decrease gradually after about 80 months of age. This dissolution of tooth germ overlap seemed to be mostly related to the eruption of the lateral incisor.
3) The angle of tooth axial inclination showed no marked change in both central and lateral incisors with age.
4) The root resorption of the deciduous lateral incisor was apt to be delayed compared with those of the deciduous central incisor and canine in relation to the rate of eruption of their successors.
5) The rotation of the permanent tooth germ was not observed frequently in central incisor, but was seen in about 40 to 50 % of the lateral incisors. The rotation of the lateral incisor seemed to show a gradual decrease as the eruption occured.

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Few reports, in the field of dentistry, have been published on the incomplete E. E. C. syndrome, which is called incomplete because it lacks one of the three symptom: Ectodactyly, Ectodermal dysplasia, and cleft lip and palate.
The present authors examined a female patient, two and a half years old, diagnosed as a case of incomplete E. E. C. syndrome with the symptoms of complete unilateral cleft and palate, thum polidactyly, and double dacriocytosis.
The following were the findings obtained from the examination.
1) Congenital missing teeth were observed as follows, _??__??__??
2) A lateral cephalogram indicated the growth of her maxilla to be markedly below normal while that of her mandible was within the normal range.
3) Morphological studies of her teeth were seriously impared on account of severe caries, but upon examining the morphological aspect of_??__??__??_a, slight tendancy toward tmowicarrodd ont was observed.
4) In order to improve the mastication, new dentures were prepared for her upper and lower jaws, and after a few months, improvements were made in the areas of mastication, pronunciation, esthetics and psychological aspect.

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To evaluate the effects of long term dental care on institutionalized handicapped children, the conditions of the caries were examined before and after dental treatment was given. Also, the relationship with respect to the side effects of the general anesthesia and the incidence were tested statistically. The following results were obtained.
1) The number of the children who had undergone dental care and the rates of the filled teeth among the decayed teeth increased after dental treatment had commenced.
2) The number of children with filled deciduous teeth increased longitudinally.
3) The number of caries suffered by the cerebral palsyed children did not increase yearly but generally reached plateau after the second year.
4) The general anesthesia was mostly administered to children with cerebral palsy.
5) The anesthesic time were almost in one hour and restorative procedure for the permanent teeth were many.
6) The side effects after the general anesthesia were many of the pharynx pain, vomitting and the bleeding from the oral cavity, respectively.
7) The negative correlation between the incidence of the side effects and the past past time after the general anesthesia were gained with the 99 % correlation coefficient in the vomitting case.

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Twelve cases of anterior cross-bite in the deciduous dentition which has been treated with chin cap appliance, were observed until the eruptions of anterior permanent teeth _??__??__??_. These were then divided into two groups;
Group I revealed normal occlusion (consist of 7 cases),
Group II revealed anterior cross-bite (consist of 5 cases).
This investigation, researching into the differences in the function of masticatory muscles between Group I and Group II, was made in order to serve as the prognosis after treatment of reversed occlusion.
Electromyographs (EMG) were recorded bilaterally on the anterior temporal muscle (TA), the posterior temporal muscle (TP) and the superficial portion of the masseter (M), duringfree chewing of gum and maximum biting. Maximum amplitudes were measured on bursts of 20 strokes in chewing and of 5 strokes in maximum biting. Thereupon, TP/TA and M/TrAa tio and TA %, TP%, M% were calculated from the maximum amplitudes. These EMG data of Group I and Group II were compared with those of the normal occlusion group. The differences of the EMG data between Group I and II were then evaluated.
The results obtained are summarized as follows:
1. The aspects of masticatory muscle activity in Group I were similar to those of the normal occlusion group as compared with Group II.
2. The prognosis after treatment in anterior cross-bile with high activity of the masseter muscle is considered to be favorable.
3. There developed a tendency that TP/TA ratio or TP% in Group I after treatment increased compared with before treatment and decreased on the periodical check up (3 to B months after treatment). On the other hand, in Group II there were not any certain changes of the TP/TA ratio or the TP% before and after treatment, and from the period after treatment to the periodical check up, these increased.
These results serve as an aid to the prognosis after treatment of anterior cross-bite in deciduous dentition.

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In children with congenital anomalies, minor anomalies may often occur in the oral regions.
This is more so in children with the Down syndrome.
It has been said that one of its characteristic tooth anomalies is a microdont.
However, only little is known about tooth size except for the malformation ones in children with Down syndrome during the deciduous tooth stage.
In this study, the authors measured the mesiodistal and bucco lingual distances in a group of 28 children with the Down syndrome during the deciduous stage, and compared it with in the group of 94 normal children at the same stage.
The foiling results were obtained.
(1) In the measurements of the upper anterior and posterior teeth, it was noted that the buccolingual distance was shorter, and the mesiodistal was longer in children with Down syndrome as compared with normal children.
(2) In the measurements of the lower anterior and posterior teeth, a slight tendency similar to those of the upper teeth, was observed but no marked difference was noted in children with the Down syndrome as compared with normal children.

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We investigated the case of an infant presenting natal teeth at AA and swellings on the gingiva in the lower central deciduous incisor region. As swellings had still remained in the area after months the extraction of the natal teeth and a part of the hard tissues were exposed, we excised, the swellings and examined them histopathologically.
A radiograph showed defined hard tissue similar to the radiopaque areas of a rice grain and having the size of a pea.
Histopathological examination showed that the swellings were vascular fibrous tissues with large number of acute inflammatory cell infiltration and in the hard tissues such as osteodentin there were found stratified structures, entrapped cells and tublar dentine structures.
We considered in this case that the differentiation of odontoblasts occured in the dentine papillae or that the lower tissue in connection with pulp had remained after the extraction of the natal teeth, and thereafter osteodentin was formed.

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An epidemiological analysis of dental caries prevalance of young permanent teeth was investigated in both Korea and Japan.
The subjects for the study consisted of 177 pupils in the 6th grade of primary school at Jeonju, Korea, and 217 pupils in the 6th grade of primary school in Fukuoka, Japan.
A Study of the occurance of dental caries was investigated using DMFS, cariostat and the questionnaires.
The results were as follows:
1) There were no significant differences between Korean and Japanese pupils with respect to dental caries and the Rohrer index.
2) There were significant differences between Korean and Japanese pupils concerning the DMFS index and the type of dental caries. The Japanese pupils in Fukuoka were characterized by multiple dental caries on the incisors.
3) Comparison between Korean pupils and Japanese pupils based on quantification type II indicated that the partial correlation coefficient of ‘the number of snacks per day’, ‘cariostat pH’, and ‘the types of snacks or beverages’ was higher in that order.
4) We analized those items of the questionnaires which were more related to an increase of dental caries based on quantification type I. As a result, the partial correlation coefficient of‘cariostat pH’, ‘the types of snacks or beverages’ and ‘the number of beverages per day’ was higher in that order in Fukuoka, Japan. Also in Jeonju, Korea, the partial correlation coefficient of ‘the types of snacks or beverages’ and ‘the number of snacks per day’ and ‘cariostat pH’ was higher in that order.
5) There was a significant difference between Korean pupils and Japanese pupils with respect to cariostat pH, and we found that the pupils in Fukuoka were more apt to suffer from dental caries than the pupils in Jeonju.
6) We grouped the pupils in Fukuoka according to the type of dental caries i. e. pupils with dental caries only in molars and pupils with dental caries in molars and incisors. We analized the two groups based on quantification type II. The partial correlation coefficient of ‘cariostat pH’ ‘the types of snacks or beverages per day’, and ‘the tooth brushing factor’ was higher in that order.
Therefore, for prevention of extensive dental caries to young permanent teeth for the pupils in Fukuoka, Japan, particular attention should be payed to the type of beverages consumed and the number of times a day they are consumed.

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How the result of the newly developed caries activity test (Cariostat) is affected by bacteriological factors and whether or not this test is valuable in determining the caries activity of children were investigated and the following results were obtained.1) When five different S. mutans strains (serotypes a, b, c, d and g) were inoculated into this test medium, the pH of each medium fell to the final pH of 4.8 ( +2, Yellow-green) after 48 hours of incubation, but when five strains of lactobacilli were inoculated, different patterns of the decrease in pH were observed. When streptococci other than S. mutans were inoculated, the pH fell to a final pH between 5.2 and 5.5 ( +1, Green).2) When 59,2-2.5-year-olds were used as subjects, a much higher correlation was attained between the number of def (def) and the results of Cariostat (C. A. )(p<0.001) than between def and the ratio of S. mutans to the total viable counts (p<0.05) or between def and the ratio of S. mutans to streptococcus counts (p<0.01).3) When 121,1 ½ year-olds were used as subjects, there was a correlation of p<0.01 between the C. A. and def at that age, and at the ages of 2 and 3. There was a correlation of p<0.05 between the C. A. at age of 1 ½ and the increment of def (Δdef) within 6 months and of p(0.01 between the C. A. at the age of 2 and the Δdef within 12 months.4) When 425,6-15-year-old children were used as subjects, a correlation of p<0.05was obtained between the C. A. and the Caries Severity Index (CSI) except for the 8-year-olds. Furthermore, the change of the average value of the C. A. according to age was similar to that of the mean CSI. Based on the above findings, it was found that Cariostat is valuable as a means in determining the caries activity in children.

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The term“submerged tooth”may be defined as a tooth which is located below the normal plane of occlusion due to various causes reason. In the primary dentition, the posterior teeth, especially the mandibular primary molar, are most often observed to be submerged. The present case report, however, describes the submerged mandibular right primary canine.
A Japanese girl,2 years and 4 months old, was brought to The Dental Clinic of Aichi-Gakuin University for the purpose of caries control. At the first visit the child was caries-free, and her Hellman's dental age was IC. She was healthy and of normal development, and the dental and medical history of her family was not remarkable. No traumatic injury of the teeth and no other dental anormalies were detected. The case was observed for 4 years, and then the submerged tooth was extracted because it was felt that it might influence the normal arrangement dentition.
Clinical and histological findings were as follows:
1. The height of the clinical tooth crown had decreased year by year.
2. The midline was off to the right.
3. The permanent successor was found to be normal.
4. The root of the submerged tooth was shorter than that of the normal one, and the surface of the root was rough.
5. Histologically, Tomes fiber in the dentin was found to be abnormal in many places.

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Epidermolysis Bullosa Hereditaria is a rare disease of the skin and/or mucous membranes. This disease is characterized by a marked development of vesicles and bullae which arise as a result of a slight trauma and may appear spontaneously. A number of classifications have been mentioned in the reports concerning this disease. The diagnosis of this case was based on the classification of Hashimoto (1981), and the patient was diagnosed as epidermolysis bullosa dystrophica Hallopeau-Siemens, which includes several oral changes and problems.
This report concerns a clinical observation of a case of epidermolysis bullosa dystrophica Hallopeau-Siemens. A boy aged 6 years was examined from the dental point of view.
The findings were as follows:
1. Physical growth was retarded, and anemia was found.
2. At the anterior fontanelle, the demineralization of the bone was seen on a radiographic examination of the skull.
3. Based on the cephalometric diagnosis, it was found that the growth in both jaws was delayed.
4. Severe dental caries had attacked all deciduous teeth.
5. The form, number, eruption and development of the permanent teeth were normal, and enamel hypoplasia was not observed.
6. Microstomia was found. The buccal and labial vestibules and palatal rugae were obliterated with scar tissue. The tongue was bound down to the oral floor, with consequent impairment of tongue mobility.
7. Local anesthesia caused no abnormality of the oral mucous membranes.

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To obtain information about the status at present of dental caries in deciduous dentition, the authors examined outpatients with respect to treatment discussed the findings. From the 4th September,1979 to the 6th August,1981 a period of about two years,2000 child patients visited the clinic of Pedodontics at the Niigata University Dental Hospital. The 635 child patients out of 2000, who were in Hellman's dental stage IIA, were examined and the findings discussed.
The following findings were obtained:
1. As for the upper anterior deciduous teeth, the number of extracted teeth and the number of teeth nessesary for endodontic treatments showed high rate of treatment among children at an early age.
2. As for the upper and lower posterior deciduous teeth, the number of teeth requiring treatment of dental caries showed a high rate among children at an early age.
3. As for the upper and lower posterior teeth, the lower teeth showed higher rate than the upper teeth requiring endodontic treatment and for teeth extraction.
4. As for the deciduous canines, the number of teeth requiring treatment showed low rate and the number of teeth requiring treatment for a restoration showed high rate a treatment.
5. There was no difference in treatment between right and left.6. The age increment conberning the percentage of restorative and endodontic treatment was not noted.
7. As for the extracted teeth, the first primary molars showed a much higher rate of increment than the second molar among the upper posterior deciduous teeth as they grew, but the lower the first and second primary molars both showed a high tendency of increment.

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Hereditary opalescent dentin is a localized dysplasia affecting the dentin, and also called Dentinogenesis imperfecta.
The patient (a three-year three-months-oldboy) diagnosed as having Hereditary opalescent dentin with no Osteogenesis imperfecta, visited the Pedodontics Clinic of Osaka University Dental School.
The findings were as follows:
1) Erupted teeth ?? ?? ?? showed a peculiar opalescent color and severe attrition.
2) Typical reduction in the size of pulp cavities was observed on the deciduous molars.
3) Histrogical observations showed cementum of normal structure, but enamel prisms and dentinal tubules were greatly reduced in number, and they appeared to be irregular.
4) This trait was observed to be autosomal dominant with high penetrance. In order to regain the vertical dimension, an over-denture was placed on the teeth, after stainless steel crowns were placed on the deciduous molars.

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