The Fourier analysis was used to determine and characterize the average forms of coronal and basal arches of deciduous anterior crossbite and to compare them with those of normal occlusion. Moreover, the morphological changes before and after treatment in the anterior crossbite treated orthodontically were studied. The materials consisted of 50 girls' stone casts of nomal deciduous dentition and 20 girls' stone casts of anterior crossbite. Their average age was 3-3/4years. The following conclusions were obtained.
(1) The averge form of the maxillary dental arch of the anterior crossbite was characterized by deviation from the normal curve in the second deciduous molar, the distal region of the deciduous lateral incisors and the central portion of the deciduous central incisors. In the mandible, deviation was noted in the second deciduous molar, the central region of the deciduous central and lateral incisors and between the deciduous cuspid and the first deciduous molar.
(2) The maxillary and mandibular bpsal arches showed deviation from the normal curve in the second deciduous molar and the central region of the deciduous central incisors; in paticular mandible deviation was also observed in the distal portion of the deciduous cuspids.
(3) Definitive differences were observed in the maxillary dental arch, maxillary basal arch and mandibular basal arch between the normal occlusion and the anterior crossbite.
(4) After orthodontic treatment, the forms of the maxillary dental and basal arches changed and approached those of the normal occlusion.

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A boy 8 years and 7 months old who had contracted osteogenesis imperfecta was found to have dentinogenesis imperfecta of the primary and permanent teeth. Dentinogenesis imperfecta is a rare form of hereditary disease which causes local destruction to the dentine. There are two forms of dentinogenesis imperfecta, one which is caused solely by independent dystrophy of the dentine itself, and the other appearing with osteogenesis imperfecta. Osteogenesis imperfecta is thought to be a hereditary disease due to the deterioration of the osteoblast and the systematical disease of the mesenchymal tissue. Out of the three major symptoms for osteogenesis imperfecta, this case showed signs of fragile bones and blue scleras, but did not reveal signs of deafness. The characteristic structure of osteogenesis imperfecta of having a hyperbrachycepharic cranium was observed, as well as the underdevelopment of the jow and cross bite of _??__??__??_ was seen. The primary and permanent teeth which have already erupted, showed an opalescent color indicating the almost complete loss of the pulp cavity.
Furthermore, the cervical region of these teeth showed a severe constriction and the roots were short.
The pathohistological findings were obtained from extracted primary teeth. The enamel and mantle dentine was found to be of normal structure. But the region between the mantle dentine and the underlying dentine developed a layer of collagen fibers causing the enamel and the mantle dentine to shear from the circumpulpal dentine. Furthermore, the dentine showed laminations and an unorderly arrangement of the dentinal tubules. Several granule objects appeared including soft tissuelike structures in the dentine. According to the clinical, X-ray, and pathohistological findings, this case was classified as the Shields type I form of dentinogenesis imperfecta.

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1. There are numerous resorption lacunae surrounding the main root canal surface of deciduous teeth. Several odontoblastic processes are different in length, which are found in the periphery of the main root canal. The walls of the main root canal are formed by cementocytes granular in appearance, which are arranged in a spiral fashion.
2. On the surface of the dentin, resorption lacunae are different in size and shape, which overlap each other to form an imbricate pattern. Openings of the dentinal tubles are found within these resorption lacunae. Ovoid or tubular shaped dentinal tubles are arranged regularly with even distance in the floor of the resorption lacunae. Edges of these lacunae are very clearly defined, which protrude as ridges to form circular arcs.
3. On the surfaces of the cementum, resorption lacunae are more or less smaller than those of the dentin. There are some protrusions of cementocyte which are connected to each other to form a granular appearance in the undamaged surface of the cementum.

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Fluoride is known to have a strongly cariostatic effect, and molybdenum is thought to have a mildly cariostatic effect. (NH₄)₂MoO₂F₄, which contains both fluoride and molybdenum, has been shown to prevent dental caries and also to arrest dental caries in rat experiments. In addition, this compound did not discolor the teeth.
The purpose of this study was to investigate the mechanism of the cariostatic effect of (NH₄)₂MoO₂F₄ from the viewpoint of effects on the mineral phase of teeth. Namely, the mode of action of (NH₄)₂MoO₂F₄ with CO₃-apatite, the change of its reaction products with CO₃-apatite in the culture medium, and the effects of (NH₄)₂MoO₂F₄on the intact enamel were examined. The results were as follows
1) Reaction of (NH₄)₂MoO₂F₄ with CO₃-apatite produced fluoridated apatite and calcium fluoride. It is considered that molybdenum substituted for the CO₃-apatite component in this reaction. The carbonate content in the CO₃-apatite decreased and the acid resistance of the CO₃-apatite increased.
2) The reaction of (NH₄)₂MoO₂F₄ at a high concentration with CO₃-apatite produced considerable calcium fluoride. It is suggested that this calcium fluoride and molybdenum detected by pretreatment of (NH₄)₂MoO₂F₄were gradually dissolved in the culture medium, and that production of fluoridated apatite and substitution of molybdenum for the apatite component took place.
3) (NH₄)₂MoO₂F₄ at high concentrations increased the acid resistance of intact enamel. Both fluoride and molybdenum penetrated into the enamel with treatment of (NH₄)₂MoO₂F₄. Calcium fluoride and molybdenum were detected in the surface zone of the enamel.
In summary, these results suggest that (NH₄)₂MoO₂F₄ gives cariostatic properties to dental minerals, especially to intact enamel.

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The aims of this study were to examine the oral conditions of Progressive Muscular Dystrophy (P. M. D. ) patients and discuss the establishment of definite plans for Dental Health Administration by mean of an estimation of the oral conditions, a questionarie and the observational records of the daily dental behaviour of daily living by the paramedical staff.
The subjects comprised 43 Duchenne type of P. M. D. patients who were housed in the institution of Minami-Kyushu Hospital.
The subjects were grouped into 3 classes of A(7 yrs. -12 yrs. ), B(13 yrs. -15 yrs. )and C(16 yrs. -26 yrs. ) respectively.
The average age was 14 years 2 months. The results obtained were as follows; The dental problems of respective groups included the complaints.
Group A-Many dental caries in deciduous teeth.
Group B-An increase of gingivitis.
Appearence of severe stage of malocclusion.
Group C-Appearence of dental caries in the permanent teeth.
An increase of severe stage of malocclusion.
Appearence of periodontal disease, deposition of dental caliculi.
The definite plans of respective groupe.
Group A-Treatment of the dental caries of deciduous teeth.
Encouragement of oral hygiene habits and instruction of toothbrushing&technics.
Group B-Treatment and prevention of gingivitis, malocclusion and trauma.
Preventive therapy for dental caries of permanent teeth.
Group C-Preventive therapy for periodontal disease.
Changes in the habits of tooth-brushing.
Etiologic analysis and treatment of malocclusion.

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The purpose of this study was to select test items among the various items of the Takagi-Sakamoto Child Personality Test which show high discriminability in the forecasting of adaptation or maladaptation at the time of the child's dental treatment. The subjects excompassed 186 children, four to eight years of age, who had visited the dental clinic of the Department of Pedodontics, Nihon University School of Dentistry at Matsudo without any previous dental treatment. The Takagi-Sakamoto Child Personality Test was divided into three groups; A, B and C according to observations of external behavior, and analyzed statistically.
The results are summarized as follows:
1. Correlations were found between the items “ anxiety pattern” and “sociability”, “lack of drive” and “independence”, “aggressiveness” and “expressiveness”and also “self control”, “adaptation to the home” and “self control” and also“ aggressiveness”, and between “adaptation to school” and “sociability”among the correlation matrix of the eleven items of the Takagi-Sakamoto Child Personality Test.
2. The items between which correlation was shown was different in the internal correlation matrix of the eleven items in each of the three groups; A, B and C.
3. As a result of discriminant analysis, it was found that the items particular to group A were “nervousness” and “adaptation to school”, items particular to group B were “expressiveness”, “self control”, “independence” and “constitution pattern”, and for group C were “anxiety pattern”, “lack of drive”, “sociability” and “adaptation to the home”.
4. The results derived from discriminant analysis of five selected items did not differ greatly from the results of discriminant analysis of eleven items. The five items selected were “adaptation to the home”, “aggressiveness”, “anxiety pattern”, “nervousness” and “independence”.

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Caries susceptibility of Balb/c mice to caries induction by Streptococcums utans serotype c, d, g strains were examined. Balb/c mice (21 days old) were given antibiotics in order to depress the oral micro flora. After depression with antibiotics, the animals were infected with Streptococcums utans serotype c, d, g strains. All the animals were bred for 95 days and fed the cariogenic diet (2000) during the experimental period. Extensive carious lesions were produced in Balb/c mice infected with S. mutans serotype c strains, which are the most frequently detected human plaques, than infected with serotype d or g strains. In mice there was observed mesio-lingual fossa in the first mandibular molar and this portion developed extensive carious lesions in addition to occlusal fissures. The appearance of the teeth in mice was very similar to those in rats, therefore it seemed to possible to use the method of caries assessment of Keyes if it were modified. Ball/c mice can be used as experimental models in caries research. A method of caries as sessment in Balb/c mice was attempted.

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The present study was so designed as to evaluate the topognostic nature of deciduous teeth in younger children and to compare it with that of permanent teeth. A total 741 deciduous teeth out of 22 boys and 18 girls, with ages ranging from 2.9-5.6 y. The tooth pressing device was specially designed and made, and each deciduous tooth was pressed axially with the pressure of 20 g, then the child was requested with his digit to indicate, which tooth was supposed to perceived pressure.
The following are the results obtained in the study.
1) The topognostic ability of deciduous teeth more mesially located showed a higher valve did than the teeth distally located.
2) Some children falsely indicated the mesially located teeth.
3) The deciduous teeth of lower jaw showed an apparent higher perception topognostically than those of upper law.
4) The deciduous teeth in children were more poorly perceived when compared with the permanent teeth in the adults.

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The purpose of pedodontic practice is to contribute to the growth and development of the whole body of the child. It is said that the oral function is established by 1 year and 6 months before the deciduous dentition is completed and after that completion, dental caries, periodontal disease and malocclusions etc appear and then, they act as elements for destroying the normal oral function.
Therefore, it is considered that the earlier oral disease appear, the worse the influences are on the growth and development of the oral function.
There are many reports on the dental caries, but on the other hand there have been few studies on the occlusion in the primary dentition so that it is an open field for research. The present authors observed the changes of malocclusion at the age of 2 to 3 and 3586 cases were investigated as a cross-section and 1270cases were followed up over a peroid of time.
The results obtained are summarized as follows:
1. It was found that incidence of the malocclusion that occurred at 2 years of age was 49.8% and at 3 years of age was 42.1%.
2. Malocclusions observed at the ages of 2 and 3 were listed in order of the most frequent occurrence.
1) deep over-bite
2) anterior cross-bite
3) open bite
4) crowdeing
5) anterio-posterior cross-bite
6) posterior cross-bite
3. There were tendencies in the changes of malocclusion at the age of 2 and 3 in that the anterior cross-bites and the deep over-bite decreased, while the anterioposterior cross-bites increased and there were no changes of the antrio-posterior cross-bites, open bites and crowdings.
4. The persentages of those malocclusion spontaneously impoving and changing in to normal occlusions from the age of 2 to 3 were as follows:
anterior cross-bite 42.0%
anterio-posterior cross-bite 40.0%
open bite 56.1%crowding 56.9%
deep over-bite 44.4%
5. The cases in which the normal occulusin at the age of 2 were spontaneously growing worse and changing in to malocclusins at the age of 3 amounted to 60.4% and also worse crowdings appeared in 61.5% of the cases.

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This study was attempted in order to investigate the visible light-cured composite resin Fotofil(Johnson & Johnson)penetration into the etched normal primary dentin through a scanning electron microscope. Extracted or exfoliated teeth(noncarious: 17 cases)were used. Class V cavities were prepared dry with the diamond bars. The dentin was etched for 1minute, then rinsed with water for 30 seconds and dried by compressed air for 30 seconds. The resin was filled in the cavities and polymerized by visible light (Activator Light) for 60 seconds.
The following observations were obtained.
1. Only in one case out of 17 cases using Fotofil was the resin penetration into the primary dentin observed. Also the length of the resin tags into the dentin were extremely short being several microns.
2. It was found that there was no adhesion by micromechanical interlocking between Fotofil and the primary dentin.

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We made an investigation into the oral findings of the first examination and of our dental care of 176 handicapped children (105 boys,71 girls), ranging from 1 to 18 years of age, who were reffered to our pedodontic outpatient clinic for treatment, during the period 1969 to 1982. They had been cared for in institutions with no dentists or in their own homes. We classified them into the MR Only Group, the Epilepsy Group, the CP Group, the Autism Group, the Blood Disease Group and the Other Group, according to their main disorder. The results were as follows.
The average age of the subjects in the first examination was 6 years and 5months, and it was the same in each group classified. There was no significant difference in the number of subjects among those groups. As for sex distribution, the Blood Disease Group and the Autism Group had more boys, but the CP Group included more girls.
The decayed tooth rate of the primaly teeth showed a gradual increase as with the increase in age, as it was 72.3 per cent at the age of 5, and 100 per cent in cases over 13 years of age. Among each group, only the Blood Disease Group showed a significantly low rate. Among the permanent teeth, the decayed tooth rate showed an increase at the eruption of the first and second molar.
In the first examination, the filled tooth rate showed a particularly low rate among children under six years of age, and it was under 1 per cent among the primary teeth. It suggested that they had not had much dental treatment before admission to school.
With regard to the degree of the caries, C₂ was the greatest number among primary teeth and permanent teeth together, and C₄ was the next great number among the primary teeth.
In our treatment, composite resin and inlay were commonly used for restration among primary teeth and permanent teeth. The rate of endodontic treatment among the treated teeth was 7 per cent. The pulpectomy and root canal treatment occupied 70 per cent.
Concerning oral anomaly, except for dental caries, a significant difference in frequency of appearance was not found among each group.

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The purpose of this study was to develop the removable plaque-pH measuring device for children and adults with complete dentition, and then to evaluate the morphological changes of plaque formation on the pH-ISFET by SEM.
1) The plaque-pH measuring device and the effect of the sucrose application on changes in the plaque-pH value.
The hydrogen-ion sensitive field effect transistor electrode (pH-ISFET) placed on the enamel was mounted into casted box-like case (10×7×2 mm). Two lead wires connected to the electrode were pluged into the device, and fixed by a guttapercha plate. This device was attached by an orthodontic sheath (ST-lock; Sankin Industry) to the buccal surface of the upper first molar of the child (9 y. )or adult (29 y. ). The subjects were asked neither to brush the electrode area nor change their eating habits. The pH value of 4-day-old plaque was recorded after the application of 10% sucrose solution to the plaque. The plaque-pH of the subjects reached the minimum pH value of approximately 4.1 within 10 minutes.
2) Figures of the plaque revealed by SEM.
The pH measuring device consisting of both pH-ISFET and the enamel was removed and examined by SEM using critical point drying at 2,4 and 6 days. It was found that the surface of the electrode was completely covered with the plaque which is similar to that on the adjacent enamel. Coccal organisms were dominant in 2-day-old plaque, and then were overcome by filamentous organisms with the lapse of time.

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On the basis of the dental health examination of 751 infants (398 boys and 353 girls) at the age of 3 years and one month +2 weeks and the questionnaires given to their mothers, factors contributing to dental caries were sought. The oral examinations of the infants included the incidence of dental caries, the pH value of Cariostat, height and weight. As for their mothers, the questionnaires were done in regard to their nursing methods, dietary habits, tooth brushing habits and other dental knowledge which might be familiar to mothers.
Discriminant analysis was carried out by subjecting those items investigated to the first class of Hayashi's quantifying theory, in which the ratio of the number of decayed teeth divided by the number of erupted teeth for each infant was chosen as an external criterion.
As a result, the factors contributing most to the dental caries at the age of 3 were found to be the pH value of Cariostat, the nursing method, the nursing environment, and the developmental factor. It was suggested that these factors might be the most important items, when oral hygiene instruction for the child is given.

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The formocresol pulpotomy technique has been widely applied for primary teeth since the 1920s.
Recently, it was, however, reported from many laboratories that formocresol had a cytotoxicity with respect to dental tissue. Therefore, we examined the formalin-guaiacol (FG) as a possible and substitutional medicament for formocresol.
We performed the pulpotomies either with FG or formocresol on human primary molars, and compared clinically and radiographically the effects of these 2 medicaments on the prognosis of the teeth.
The results were as follows.
1. A 76 percent success rate (133 out of 175 teeth) was obtained in pulpotomy with FG and a 60.4 percent (55 out of 91 teeth) with formocresol. This success rate of pulpotomy with formocresol was lower than in other reports. Our data, however, indicates that the pulpotomy procedure was better with FG than with formocresol.
2. Most of the failures in pulpotomy with FG were observed in the second year after the treatment. Seventy out of 82 teeth (85.4%) which did not show any signs of failure for 2 years after treatment have a good prognosis so far.
3. Internal root resorptions were radiographically observed in 7 of 175 (4%) FGtreated teeth.
4. It seems that the FG pulpotomy procedure may cause the slightly earlier eruption of the successive permanent teeth, compared with the formocresol pulpotomy technique.

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The purpose of this study was to survey the status of the dental caries prevalence among the deciduous teeth of nursery school children in the north district of Sendai City during the period from 1972 to 1981.
The data obtained at three year intervals were statistically analysed and the results were as follows.
1. The caries prevalence among the deciduous teeth in all age groups decreased year by year. In all age groups, the prevalence rates of caries and the average number of def teeth per person surveyed in 1981 were significantly lower than those of 1972.
2. The prevalence rates of caries in children of 2 and 3 years of age decreased remarkably until 1975, while the prevalence rates of caries in children of 4and 5 years of age decreased after 1978.
3. The average number of def teeth per person in children of 2 and 3 years of age showed an average decrease of about 1 to 2 def teeth until 1975, and the tendency towards this decrease lessened after that. On the other hand, the average number of def teeth per person in children of 4 and 5 years of age decreased remarkably after 1975.
4. The rates of def teeth among all kinds of deciduous teeth in all age groups decreased year by year. The rates of def teeth among the deciduous upper incisors, molars and lower molars surveyed in 1981 were significantly lower than those of 1972 in all age groups.
5. The rates of tooth surfaces with df in all kinds of tooth surfaces in all age groups decreased year by year. In all age groups, the rates of tooth surfaces with df on the interproximal surfaces of deciduous upper incisors, and occlusal surfaces of upper and lower molars in 1981 were significantly lower than those of 1972.

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Restorations with preformed primary crowns have been widely applied to the carious primary molars. However the effects of placing preformed primary crowns on the neuro-muscular system of masticatory muscles are not clear yet.
The present study was so designed to evaluate the effects of preformed primary crowns placed on the neuro-muscular reflex of masticatory muscles. Investigations were made by measuring the duration of the silent period and its frequency on the electromyograms. Six children (4-5 years old) were examined in this study. Surface electrodes were placed on the temporal and masseteric muscles bilaterally, then the children were instructed to perform tooth tapping at a rate of 76 times per minute with the aid of a metronome, and EMG during ten serial tappings were recorded. EMG recordings before and after placement of the preformed primary crowns were obtained sequentially. The results obtained in the present study were as follows.
1) The number of occlusal contacts increased significantly after placement of the primary crowns (p<0.01).
2) The occurence of the silent period increased after placement of the primary crowns in all of the examined muscles.
3) The duration of the silent period showed no significant differences statistically between before and after placement.
4) The coefficients of the variation for the duration and its latency showed a tendency to decrease after placement of the primary crowns. These may indicate that occlusal improvement of the primary molars favorably affects the neuro-muscular system during tooth tapping, which in turn stabilizes the feed back mechanism from afferent impulses.

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The facial growth in children having facial soft tissue was analyzed by using the Moire Topography.400 subjects,3 to 12 years of age, were used in this investigation. Moire Topography is a new technique used for observing the contour lines of an object. The advantages of this method are threefoldno contact with the patient is required, Moire gives the highest degree of accuracy, and very little time is needed. Optional areas and the Ectocanthion Moire Pattern, a typical Moire pattern, were investigated.
The results were as follows:
1. The growth of the sectional areas correlated with age, but it did not always run in parallel with age. At each age, the growth value for the male was larger than that for the female. The age groups in which the annual increase was large were 3-4,6-7 and 9-10 year old for both sexes. The growth rates for each section were divided into three categories based on their values; the Nasion section was small, the Pronasale, Subnasale, Labrale The growth rates for each section were divided into three categories based on their values; the Nasion section was small, the Pronasale, Subnasale, Labrale superius, and Orbitale sagittal sections, were medium, and Labrale inferius, Mentum and Median sagittal section were large.
2. The pattern Index was defined as the proportion of the facial width, and it was found effective for diagnosis of the facial outline. The shape of the facial outline gradually progressed from round to longer (inverted paraboloid shape)with increasing age. The cause of such a change was mainly dscribed to the remarkable growth of the mandible and zygoma. 'The Ectocanthion Moire Pattern spread along the outline of the face. The lines in this pattern became wider on the cheeks of 3-5 year-olds of both sexes. In 6-12 year-old males, it projected more on the regio zygomatica, regio parotideomasseteria, and regio mentalis. On the other hand, in the female the line became wider with increasing age, but there was no typical change.

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The occurrence of malocclusion in the primary dentitions has been established. A few studies have revealed the incidence of malocclusion in incompleted primary dentitions. The purpose of this study is to investigate the change of the occlusion form and the duration of the oral habits in the children from the age of 1 year and 6 months to 2 years.
707 children enrolled in the Dental Health Service Program in Kunitachi City were available for examination. As part of oral health screening, the occlusion of the incompleted primary dentitions was observed for frequency of abnormalities. In addition, the appearance of oral habits and the effects on the occlusion were investigated.
The following results were obtained:
1) The malocclusion in the 2 years old children was 47.2 percent of the 707 children examined.
2) The most frequent malocclusion observed was an open bite, which had a frequency of 15.7 percent among the 707 children. The remaining malocclusions were: anterior cross bite,14.3 percent; deep bite,10.2 percent; edge to edge bite,4.4 percent; crowding,2.0 percent; posterior crossbite,0.7 percent.
3) 88 children who had normal occlusion at 1 year and 6 months of age changed to malocclusion at 2 years of age, and especially to open bite and to deep bite.57 children (anterior cross bite 16, open bite 15, edge to edge bite 11, deep bite 10, crowding 5) who had malocclusion changed to normal occlusion.
4) The appearance of oral habits in children 2 years of age was observed in 227children (32.1%). This frequency decreased about 10 percent in comparison with children 1 year and 6 months of age. The finger sucking habit revealed the greatest percentation (79.8%) among all oral habits.
5) 78.4 percent of the open bite children has the habit of finger sucking.27 out of 38 children who changed to open bite from normal occlusion continued finger sucking until 2 years of age. On the other hand,6 out of 15 children who changed to normal occlusion from open bite stopped finger sucking. In view of these facts, the finger sucking habit appear to have serious effect on the open bite and there seems to be a cause effect relationship between the two.

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In 9 areas of Japan, dental epidemiologic data were collected for 2 years at an interval of 6 months from 1979 by means of a questionnaire, oral examination and caries activity test from 3307 infants who had undergone dental health examination at 1_1/2 years of age.
A large amount of information was given in the area of nursing, the growth and development of children, the condition of their health, their breeding, oral habits, changing of their dietary pattern with growing, the eruption of the teeth and the development of the occulusion, the occurrence of diastema in the spaced type of primary dentition, the connection of the dental caries, caries activity and so on.

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In 9 areas in Japan, dental epidemiologic data were collected for 2 years at an interval of 6 months from 1979 by means of a questionnaire, oral examination and caries activity test from 3307 infants, who had undergone dental health examinations from the age of 1_1/2. However the number of infants decreased year by year and 1283 infants remained in the examination at the age of 3_1/2.
As a result, much information was obtained conserning the area of nursing, the condition of the health, breeding, oral fiabits, changing of the dietry pattern while growing, the condition of the dental caries, caries activity and so on.

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The purpose of our study was to establish the methods of conducting dental health surveys on 1Y6M old children, to find systemic oral diseases and to prevent dental caries. The subjects were the children 1Y6M to 3Y6M old children at 9locatities in Japan (Iwamizawa, Morioka, Sendai, Tokyo, Yokosuka, Ibaragi, Tokushima, Hiroshima, Fukuoka), and every 6 months were examined with respcet to their oral condition and habitat factora.
The eruption of deciduous teeth was related to the development of mastication and occlusion, and important for the prevent dental caries. In this report, the eruption of deciduous teeth were examined.
The results were as follows;
Rate of the eruption of deciduous teeth
At 1Y6M old most deciduous incisors were erupted, and the rate of eruption of the deciduous cuspid was 78.46% in the upper jaws and 66.65% in the lower jaws. The rate of eruption of the 1st deciduous molar was 94.50% in the upper jaws and 88.69% in the lower jaws at 1Y6M of age. And the rate of eruption of the upper 2nd deciduous molar was 14.38% at 2Y0M of age and 67.28% at 2Y6M of age, but the rate of eruption of the lower 2nd deciduous molar was 36.43% at 2Y0M of age and 88.93% at 2Y6M of age. At every age period, concerning the rate of eruption of deciduous teeth the left sides showed a somewhat higher rate than the right sides by compariosn, and boys showed a somewhat higher rate than girls. In the rate of eruption of deciduous teeth the upper 1st molar showed a higher rate than the lower jaws, but the lower 2nd molar showed a higher rate than the upper jaws. As for compariosons, between local areas in the rate of eruption of deciduous teeth at Iwamizawa and Yokosuka was higher than other, and the rate of eruption of deciduous teeth at Ibaragi was lower than in the other areas.

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The purpose of our study was to establish the methods of dental health survey on 1Y6M old children, to find systemic oral diseases and to prevent dental caries.
The subjects were children 1Y6M to 3Y6M of age at the 9 locatities in Japan (Iwanizawa, Morioka, Sendai, Tokyo, Yokosuka, Ibaragi, Tokushima, Hiroshima, Fukuoka), and at every 6 months were examined with respect to their oral condition and habitat factors.
The eruption of deciduous teeth was related to the develpoment of mastication and occlusion, and important for the prevention of dental carise. In this report, the eruption types were examined.
The results were as follows;
The eruption type of deciduous teeth were classified into 12 types. Most of the eruption types at 1Y6M and 2Y0M of age were as follows. _??__??__??_At 2Y6M,3Y0M and 3Y6M of age, many deciduous teeth were completely erupted.
The types which had fewer numbers of erupted deciduous teeth at 1Y6M of ages howed a tendency to transfer to the types with fewer number at 3Y0M of age.

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The dental health examination of children at the age of one year and six months was conducted in nine areas (Iwamizawa, Morioka, Sendai, Suginami (Tokyo), Kanagawa, Ibarage (Osaka), Hiroshima, Tokushima, Fukuoka) of Japan. In this study, the superior labial frenum occupied one part of the examination. The following subjects were examined with each person, namely the frequency of the abnormal frenum, longitudinal change of the abnormal frenum and the relationship between the abnormal frenum and the upper mid-line space.
The subjects were 902 children who were examined every six months from one year and six months of age to three years and six months of age. The results were as follows.
1)The abnormal frenum was classified into the five types at one year and six months of age.
2)The maxillary abnormal frenum decreased in the higher age brackets. The abnormal frenum was observed in 27.3% of the subjects at the age of one year and six months,14.3% at the age of 2,9.3% at the age of 2 years and six months,6.4% at the age of 3 and 5.9% at the age of 3 years and six months.
3)Observating the longitudinal change of the abnormal frenum with the same persons, half of the children with an abnormal frenum returned to a normal frenum from the age 2.
4)The appearance of the upper mid-line space in the children with the abnormal frenum was most frequent among all the subjects, in each age bracket.
5)In the children with the abnormal frenum, over than half of the children with the upper mid-line space were observed, in each bracket, except at one year and six months of age.
6)In particular most of the children with the no changed abnormal frenum from one year and six months to three years and six months of age had the upper midline space.
7)It was considerated that the abnormal frenum was not the cause of origin the upper mid-line space, but was the result.

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The purpose of this study was to complete the dental health examination of one and a half year old infants. As part of the intraoral examination, we surveyed the age-related changes of interdental spaces in lower age infants based on visual examination.
Oral health examinations were carried out on 902 children at the age of 1 year and 6 months to 3 years and 6 months at intervals of 6 months in 9 areas in Japan. We observed the incidence of interdental spaces. The following results were obtained.
1. There were great regional differences at the age of 1 year and 6 months and 2years, but the regional differences decreased with the increase of age.
2. The incidence of interdental spaces was noticed to be more frequent in the upper jaw than the lower jaw, and at the mesial and distal to the deciduous canine. The incidence of interdental spaces was the highest in the so-called “primate spaces” in the upper and lower jaw.
3. As to the age-related changes, the incidence of interdental spaces gradually increased with the passing years at the incisal segment, but on the other hand the incidence of interdental spaces decreased with the increase of age at the lateral segment.
4. As to the individual changes at the interdental spaces between the right and left central incisors, about two thirds of the subjects showed no change in the upper and lower jaw. In most of the remaining changing types, spacing occured gradually. Especially in the lower jaw, in the one fifth of the subjects, spacing occurred.
5. At the interdental space between the right and left maxillary deciduous central incisors, the proximal caries incidence of the closed type was grater than that of the spaced type, the difference being significant, eapecially at the age of 1 year and 6 months.

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From 1980 to 1982, primary occlusion changes, in each type of eruption and longitudinally, were investigated every 6 months in 736 children aged from 1.5years to 3.5 years in Iwamizawa, Morioka, Sendai, Tokyo, Yokosuka, Ibaragi, Tokushima, Hiroshima, and Fukuoka. The results are as follows.
1) Primary occlusion in 1.5-year-olds was connected with the number of eruptive teeth. The results showed that the fewer the teeth empted, the more the cases of deep bite increased. The more the teeth erupted, the more the cases of 1/2occlusion increased.
2) In the sectional investigations at every six months,1/2 occlusions were observed most frequently, and followed by deep bite, the mesioclusion and open bite.
3) Occlusal changes examined every year for all of the 736 individuals, showed 126patterns. The most frequent pattern was observed in the cases, in which 1/2occlusion existed at every stage (20.8%), and followed by the cases, in which 1/2occlusion existed untill 3.5 years of age (10.6%) and in which deep bite at 1.5years of age changed to 1/2 occlusion at 2.5 years)of age (9.4%). In the deep bite, the occlusion is inclined to be shallow in each age bracket.
4) In the cases of mesioclusion at 1.5 years of age, the longitudinal investigations showed that the cases of deep mesioclusion existed until 3.5 years of age, were the most frequent in the deep mesiocclusion, but the cases showing the changes to the 1/2 occlusion were the most numerous in the shallow mesioclusion.

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To clarify the effect of oral habits on the prevalences of dental caries and malocclusion in deciduous dentition, oral examinations and questionaire surveys of oral habits were conducted on infants beginning at the age of one and a half years. The prodedures were repeated with the same individuals at 6 month intervals until the age of three and a half years. The studies were carried out in the nine areas of Iwamizawa, Morioka, Sendai, Suginami, Yokosuka, Ibaragi, Tokushima, Hiroshima and Fukuoka.
The data obtained were statistically analysed and the findings were as follows.
1. The prevalence of caries in the deciduous teeth of children with habit of fingersucking was significantly lower than that of children without this habit at every age level.
2. The prevalence of caries in the deciduous teeth of children who habitually bite things other than fingers during sleep was lower than that of children without such habits at the age of 2.5,3.0 and 3.5 years.
3. The prevalence of caries in the deciduous teeth of children having the habit of sleeping during breast feeding was higher than that of children without this habits at every age level.
4. The occurence of a lip-sucking habit in children with anterior crossbite was significantly higher than in children with normal occulusion at the ages of 2.0,2.5 and 3.5 years.
5. The occurence of habit of finger-sucking and habitually biting things during sleep in children with open bite or maxillary protrusion was significantly higher than in children with normal occlusion at every age level.

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For the purpose of becoming familiar with the characteristic nursing environment of one and a half year old infants in various localities, questionnaires given to the mothers of 210 infants in Ibaragi (Osaka),340 in Tokushima and 288 in Yokosuka were investigated. Also to discover the relation ship between the nursing habits at the age of one and a half and the dental caries prevalence at the ages of two and a half, three, and three and a half, the questionnaires to the mothers and the results of the oral health examination of the infants were analysed. The subjects were 33 infants in Ibaragi,130 in Tokushima and 193 in Yokosuka who were examined every six months from the ages of one and a half to three and a half years.
The results obtained were as follows:
1. The rates of families which consist of more than five members and of the one and a half year old infants who were reared by their grandmothers through the daylight hours were higher in Tokushima than in Yokosuka and Ibaragi.
2. The rates of mothers who were employed were higher in Tokushima and Yokosuka than in Ibaragi. In Tokushima, many mothers were full-time employees such as officeholders and clerks. In Yokosuka, many mothers were self-employed engaged in agriculture, and in other occupations.
3. At the age of one and a half years, the rates of children having nursing bottle while sleeping and of the not yet being weaned were higher in Tokushima than in Yokosuka and Ibaragi.
4. At the age of one and a half years, the rates of regular tooth brushing and of those who were receiving the mother's help while brushing were very low in Tokushima.5. At the age of one and a half years, concerning between-meal snacks, the rates of irregular eating, eating more than three times, and eating while playing were higher in Tokushima than in Yokosuka and Ibaragi.
6. At the age of one and a half, the rate of eating of sweets as between-meal snack 320was higher in Yokosuka than in Tokushima and Ibaragi.
7. Of the nursing environment of children from the age of one and a half years, the age of the child in relation to the ages of the other children in the family was related to the caries prevalence at the age of two and a half years, while the number of family members, rearing a child through the daylight hours, completing of weaning, the help of the mother while brushing, the regularity of eating between-meal snacks, the number of between-meal snacks were related to the caries prevalence at the ages of three and three and a half.
8. Concerning all six items except the number of children listed above, the rates of cariogenic answers in the questionnaires were higher in Tokushima than in Yokosuka and Ibaragi.

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Dental surveys were made of infants of one year and a half of age from nine areas throughout Japan. Pedodontic Departments of nine dental schools participated in these surveys, and the methods of the investigation were to standardize as much as possible. Out of these, three areas, Sendai, Yokosuka, and Tokushima, were selected here, and the correlation between dietary habits and dental caries incidence was investigated.
Results:
1) As to the incidence of dental caries, bottle-fed infants tended to show the lowest, and irregularly fed children showed higher in ratios each area. The dft index was significantly higher in one area.
2) Fooding styles of the infants were different among the areas, and, in general, the incidence of dental caries tended to be higher in the group of breast-fed infants, and lower in the group of milk-fed infants.
3) Bottle feeding lasted up to 12 months after birth in a few cases, and it was suggested that bottle-fed infants showed a tendency toward a higher incidence of multiple dental caries.
4) Infants who ate much food when they were one year and a half of age showed a lower tendency concerning the incidence of caries.
5) As for between mealsnack, the caries incidence was higher in groups where snacks were eaten at unfixed times frequency, and place. The authors, therefore, were able to propose an instruction as guide for the prevention of dental caries.

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Oral examination and the caries activity test by Cariostat was performed on 1 _1/2 year old infants in 9 different areas during a period of 2 years, to study how the prophylactic treatment of the dental caries of 1 _1/2 year old infants should be carried out.
In this paper, the change of the percentage of subjects who have dental caries and the possibillity of the prediction of the prediction of caries initiation according to caries activity was investigated.
The results were as follows:
(1) The rate of the subjects who had dental caries increased according to age and the difference of the maximum and minimum of that rate among the 9 areas was smallest at 1 _1/2 years of age but it was largest at 3 years of age.
(2) The mean deft and defs values increased according to age but the change of the mean value of the caries activity by the results of Cariostat almost stopped after 2 _1/2 years of age followed by a rise from 1 _1/2 to 2 _1/2 years of age.
(3) A significant correlation was obtained between the caries activity by the results of Cariostat and the deft and defs values respectively.
(4) The use of Cariostat as a caries activity test to predict the caries initiation or progression in the near future may be valuable.
(5) Although the caries activity was low at 1 _1/2 years of age, the mean deft values more increased according to the higher level of the caries activity after 1 year.

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Recently prophylactic treatment for the increased dental caries of the infants has been proposed and systematic control to surpress the initiation of dental caries is desired.
In this paper, to collect the data related to the method of preventing dental caries, the questionnaires concerning 2,2_1/2,3 and 3_1/2 year old subjects at 9different areas were longitudinary analysed by the screening methor (presence or absence of dental caries or high or low of dental caries activity measured by Cariostat).
The results were as follows:
More items of the questionnaires were selected by the screening method with the presence of dental caries.
The selected items were almost entirely closely related to the dietary habit and especially related to the between-meal snacks (contents, regurality of taking, frequency. place to eat and etc. ).
Based on these results, the relationship of the dietary habit and dental caries of infants is proved more efficiently by the results of Cariostat than by the results of oral examination.

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Consciousness of the esthetic appearance of deciduous anterior teeth was investigated. Questionnaires were used, and 105 child dental patients age of two to seven whose anterior teeth were repaired esthetically, and their mothers were selected as subjects of the survey. The following results were obtained.
1. Approximately two-thirds of the subjects answered that the motivation to visit the hospital was treatment of dental caries despite freedom from toothache. Improved maternal consciousness of dental health was inferred.
2. Approximately one-half identified the upper anterior teeth as their primary concern. "Being unsightly" as a reason was the third among the mothers, and the first responce among the children themselves. Apparently, the demand for esthetic repair of maxillary anterior teeth was extremely strong.
3. More than half of the children experienced application of tooth-darkening medications. Although the younger children were not conscious of darkened teeth,21 % of the older children clearly expressed the feeling that darkened teeth were unsightly. As many as 17% of the mothers answered that they felt darkened teeth were not something the children should have to bear. Certainly, their intentions should not be neglected.
4. Concerning psychological and behavioral effects, some mothers reported that negative behavior accompanied darkened teeth, and that complete repair of these teeth resulted in more positive behavior. These effects were most apparent in children three-and-a-half years and older, being somewhat less noticeable in younger children, with report of many episodes occuring both at home and at nurseries. Condition of the anterior teeth had a great impact of the children's personal relationships.
5. An overwhelming majority of mothers acknowledged that the state of the anterior teeth of children affected their psychology and behavior, and wanted every child to recieve complete, esthetic treatment. Only 2% answered that mere suppression of the progress of dental caries was sufficient for deciduous teeth.
6. Unsatisfactory prognosis of the application of diammine silver fluoride was reported in many cases. Thus, misuse of this agent caused by the neglect of primary indications was suggested. In conclusion, the recovery of clean, white anterior teeth, a primary concern among children, should be the best opportunity for having them realize the significance of dentistry and dental health.

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The purpose of this report is to analyse the actual condition of the outpatients who visited the clinic of Pedodontics at the Niigata University Dental Hospital and to evaluate the role of the clinic in the local city of Niigata and what is expected of it. From September 1979 to August 1982 for a period of three years,3199 child patients (1667 boys and 1532 girls) visited our clinic.
The following findinge were obtained;
1. The mean number of the first monthly visit was a little under 100 patients.3-year-old children occupied the largest percentage of outpatients.
2. About 80% of all patients had dental caries as their chief complaint.44% of all outpatients came from Niigata City, but almost 40% of the outpatients took more than 4 hours to travel to and from the clinic.
3.11.8% of outpatients were affected by some sort of systemic disease, and half of them had neuro-cerebral systemic disease. All of handicapped children were treated under local anesthesia in our clinic in the same way as we treated normal children.
4. As to the type of caries incidence in the deciduous dentition, type III plus IV which were severe dental caries amounted to almost 83%.
5. At dental age IC, the number of treated deciduous teeth per patient was 6.5 teeth. At HA, it was 13.5 teeth. The number of restored permanent teeth showed a gradual increase as the dental age increased.
6. Concerning the types of restorative treatment, about 40% of the carious teeth was treated with composite resin at every dental age. The use of the preformed metal crown gradually increased a dental age increased.
7. The vital amputation using he calcium hydroxide technique wae commenly used as the endodontic treatment.
8. Occlusal guidance was performed for 28% of all outpatients.118 outpatients were treated with active appliances such as removable active appliances, lingual arch active appliances and the direct bonding system.
9. Pediatric oral surger- such as the removal of a supernumerary tooth and the frectomy, was performed for 114 outpatients.

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Epulis is a clinical term for benign and limited tumors on the gingiva. It arises from the gingiva, periostium of the alveolar bone and the periodontal ligament. Though epulis is histopathologically classified into several types, epulis consisting of areas of ossification is rarely noted. Epulis occurs more frequently in adults and rarely in elderly people and children.
This report concerns a case of epulis which was observed in an 11-month-old female infant. Her deciduous teeth had not erupted. Epulis was observed on the area of the upper right deciduous central incisor.
Histopathologically, it consisted of fibrogranulomatous tissues, and areas of ossification were observed. The histopathological diagnosis was epulis fibrosa osteoplastica.
A case report concerning epulis before the eruption of deciduous teeth was considered rare except for cases of congenital epulis.

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1. A case of congenital teeth erupting at the lower deciduous central incisor was investigated. The teeth proved to be feeding disturbance and were extracted.
2. A histopathological investigation showed that the congenital teeth were about normal with regard to the pulp, Hertwig's epithelial sheath, and the dentin.
3. A scanning electron microscopic observation of the labial enamel clearly showed hypoplasia of the enamal.

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TMJ dysfunction syndrome has been defined as the presence of one of or more of these symptoms.
These symptoms include: (a) pain and tenderness in the region of the muscles of mastication and temporomandibular joint (TMJ); (b) sounds during condylar movements; (c) limitation of mandibular movement, etc. In addition, the abscence of organic changes in the TMJ must be noted:
This report is a case presentation which is aimed at discuss in the etiological factors and clinical correspondence in according to our clinical system for the TMJ dysfunction syndrome in adolescence.
Case 1: The symptoms were disappeared themselve, but occlusal adjustment and occlusal reconstruction occured because of the removal of the cuspal interferance which was probably the primary factor.
Case 2: The etiology was not clear, and after the occlusal splint was worn for the diagnose, occlusal adjustment and occlusal reconstruction was performed, and 8 8 was extracted which was considered another factor.
Case 3: First, an anterior bite plane splint was worn for emergency therapy of the acute symptoms. Later, after orthodontic procedures had been performed, because of the removal of the premature contact in 2/2, occlusal adjustment and occlusal reconstruction were taken place.
Case 4: The symptoms were slight, and orthodontic procedures were performed, because the premature contact in 2/2 was considered to be a primary factor. In the future we shall hope to make further investigations to clarify the etiology and to establish the diagnose and treatment of adolescent the TMJ sysfunction syndrome along the lines of our clinical system in this study.

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It may be occasionally happened that the patients swallow the restorative object or broken denture. Such cases may actually cndanger the lift of the patient.
We encountered the case of a bronchial foreign body swallowed by seven-yearold boy.
1) The foreign body was a broken fragmant of space maintainer in the right bronchus.
2) His mother took him to the surgeon for consultation, because she suspected the swallowing of a broken foragment of the partial denture, but the surgeon could not find the fregment.
3) The next day he visited the clinic of Fukuoka Dental College, and we suspected that the patient had swallowed the bronchial foreign body and he was referred to the otorhinolaryngologist who removed the fragment.

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The incidence of approximal caries in the deciduous molars in which no approximal caries were detected by inspection and probing, was investigated using the bitewing dental X-ray. The comparison was made between the two groups which were classified according to the severity of the occlusal caries. The low incidence group consisted of no caries and the degree of C₁ on the occlusal surface and the high incidence group consisted of the degrees of C₂-C₃ on the occlusal surface.₂The difference of the incidence in proximal caries was statistically examined between the right and left sides, upper and lower jaws, and examined as to whether or not the approximal caries will be more frequently and deeply affected in the high incidence group of occlusal caries than in the low incidence group. The results were as follows:₂1) There was no significant difference between the right and left side in the incidence of approximal dental caries.₂2) When we compared the incidence of approximal caries between the upper and lower jaw, the higher incidence was found on the distal surface of the 1st deciduous molar and the mesial surface of the 2nd deciduous molar in the lower jaw.₂3) The higher incidence group in regard to occlusal caries showed the higher incidence of approximal caries on the distal surface of the 1st deciduous molar and the mesial surface of the 2nd deciduous molar in both jaws in comparison with the low incidence group.₂4) There was no significant trend towards deeper caries in the approximal surface in relation to the severity of occlusal caries.

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The changes in the behavior of children in relation to dental procedures were investigated from the clinical records of the behavior of children during dental treatment rated by Frankl's Behavior Rating Scale with respect to 166 subjects, who were 2 to 5 years of age and had had no previous dental experience.
The results obtained were as follows:
1. The number of children who were uncooperative at the first visit for an examination decreased among the upper age groups. The number of those who were cooperative at the first visit, but became uncooperative during the following dental treatments, was greater in the age group of 2 to 4. Furthermore, the period when these cooperative children turned into uncooperative ones was mostly at the time when the first dental treatment was performed. Child patients of the emergency group, who received actual dental treatment at the first visit tended to be cooperative, in comparison with regular child patients who were given only the examination procedures at the first visit and were treated from the second visit. Also the emergency group needed longer time to become cooperative, especially between the ages of 2 to 3.
2. The number of children who appeared to become uncooperative due to an injection for local anesthesia increased in the upper age groups. These children also needed longer time to become cooperative for all age groups.
The results obtained in this study generally agree with the previous articles, in spite of the lack of objectiveness in rating the behavior of children. It may be concluded, therefore, that the clinical and subjective evaluation of the behavior of children in the way performed in this study could be useful in managing the child patient during pedodontic treatment.

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The authors administered persistant cephalexin (L-CEX) to forty-eight child patients who exhibited acute suppurative inflammation in their oral cavities, examined the clinical effects, and moreover, performed " questionnairing on drugs used ", using their mothers as subjects. The following conclusions were derived.
1. The rate of efficacy of L-CEX was 70.8% and 91.7% with continuous dosages for three days and five days, respectively, in an objective rating method, and 93.7% according to subjective estimation of the doctors in charge. Thus, the satisfactory efficacy of L-CEX was apparent.
2. Concomitant use of enzymic antiphogistics tended to increase the number of cases with remarkable effectiveness.
3. Concerning side effects, four cases of slight diarrhea and one case each of nasal hemorrhage, vomiting or gastric dysphobia were observed. No particularly serious side effects were reported. Discontinuation was not necessary.
4. High effectiveness was obtained in such a short period of time as three to five days in cases of various suppurative symptoms of the oral cavity. Because the safety factor was relatively high, too, L-CEX could be considered to be the first choice in this medical region.
5. Because conventional antibiotics were not satisfactory in respect to their taste, odor, color and appearance, not a few children rejected taking them with reluctance. However, the majority of child patients took L-CEX without much reluctance, in some cases, voluntarily. No patient refused completely. Therefore, L-CEX may be considered to be easy for children to take.
6. Conventional antibiotics required administration at every six-hour interval. Therefore, such regular administration frequently failed to be performed, because of sleeping at night and staying at nursery or school in the daytime. L-CEX can maintain satisfactory blood concentration by aministration at twelve-hour interval, and be given directly by parents in the morning and evening. These features of L-CEX could be considered to be important merits in preventing failure to administer it.

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Five people from three families missing numerous teeth were investigated. Because it was not certain whether the third molar in a young child was missing, the third molar was not numbered.
The results obtained were as follows:
1. The persons with missing teeth had no general disorders such as ectodermal dysplasia.
2. The rate of the persons missing teeth in three generations was 26.5%. It was higher than the general rate,4.0%.
3. The ratio of male to female was about 1: 2.
4. The lower second premolar, upper canine, upper first and second premolar were missing frequently, and the upper and lower first molar, upper central incisor, lower first premolar were never missing.
5. It was strongly suggested from the above mentioned findings that the missing of numerous teeth was due to phylogenetic retrogression.
6. The missing of numerous teeth did not affect the craniofacial growth and development.

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