The acid-resistance of the tooth surface is strengthened by the two-step treatment (F-La treatment) with acidulated-phosphate fluoride and lanthanum chloride solutions as previously reported by this author et al. Recently, a study was made to examine some clinical applications of the treatment. The acid-resistance effects and the actual condition of the F-La treatment were investigated on human deciduous enamel. Analysis was made using the electron probe X-ray microanalyzer before and after the acid-solubility test. The results were as follows:
1) As compared with those conditions before treatment, the acid-resistance of deciduous tooth enamel increased over six times after the F-La treatment and over two times after just the F-treatment.
2) It was necessary to treat deciduous tooth enamel with 1 mol/l of phosphoric acid prior to the F-La treatment.
3) A three minute treatment with both F and 1% La sufficed for the F-La treatment.
4) Fluorine and lanthanurn penetrated up to approximately 15μm from the enamel surface with the F-La treatment. Even after the acid solubility test, a sufficient quantity of the stated chemicals remained, thus protecting the tooth substance.
5) The solubility of the deciduous tooth enamel was 34% higher than that of the permanent tooth enamel. After the F-La treatment, however, the former diminished to the level of the permanent tooth. Based on these experimental results, one can reconfirm the fact that the chemical reactivity of the deciduous enamel is higher than that of the permanent enamel.

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The purpose of this study was to evaluate the relationship between gingivitis and the local etiologic factors in children with Down's syndrome. The subjects consist of 46 children with Down's syndrome aged 13 to 60 months (30 boys and 16 girls) and 16 healthy control children aged 9 to 24 months (9 boys and 7 girls).
Both group of the subjects had deciduous dentition. The plaque index (PHP modified), the prevalence of gingivitis (PM index) and the crowding score (using the Matsumoto method,1980) were calculated based on the data obtained from the subjects. With respect to the three parameters mentioned above, the following were examined.1) The comparison of the children with Down's syndrome to the control children.2) The chronological change of the children with Down's syndrome.3) The correlation among them on the children with Down's syndrome. The following results were obtained.
1) The PM index in the children with Down's syndrome is about 4 times that of the control children.
2) The crowding score in the children with Down's syndrome is double that of the control children.
3) The PM index becomes higher with the increase in age of the subjects. On the other hand, the crowding score becomes less with the increase in age.
4) No relationship between the PM index and the crowding score was found, nor between the crowding score and the plaque index.
5) No significant correlation was found between the PM index and the plaque index.
These results show that the plaque index and the crowding score as local factors have less relevance to gingivitis in the deciduous dentition in the children with Down's syndrome. Therefore, further investigation is necessary concerning other local factors and the systematic factors.

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The occurrence of pigmentation in the anterior portion of the gingiva of Japanese children and young adults (2675 females and 3043 males) in Tokyo and Saitama prefecture was examined from 1982 to 1986. The age of the test subjects ranged from zero to nineteen years. The findings were as follows:
1) The brown pigmentation was seen mainly in the attached gingivae between the left and right canine teeth in the maxilla and/or the mandibula.
2) The pigmentation first appeared at the age of two. The incidence greatly increased at the age of three, reaching the maximum,60%, at the age of six. In females, the percentage began to decrease at the age of eleven and showed about 6% at the age of nineteen. On the other hand, in males, the percentage began to decrease at the age of fourteen and showed about 25%at the age of nineteen.
3) The pigmentation was generally band-shaped and appeared first in the maxillary gingiva and then in the mandibular gingiva. In a few cases it appeared first in the mandibular gingiva after the age of six.
4) The pigmentation disappeared temporarily at the portion of exfoliation from deciduous teeth to permanent teeth. It seems that the pigment begins to fade before the exfoliation of the deciduous teeth and reappears after the eruption of the permanent teeth.
5) After the age of ten, the maculate pigmentation increased with the increase in age at the root region and the interdental region of the gingivae. It is suggested that these are the fading processes of the band-shaped pigmentation.
6) The pigmentation finally remained at the root region of the permanent lateral incisors or canine teeth, and in the interdental region between permanent lateral incisors and canine teeth or between the permanent central and lateral incisors.

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The analysis of the change and stress of the restoration was carried out regarding the depth and different materials employed in class II cavity preparation using the finite element method.
For the two dimensional finite element model for the primary teeth, the disto-lingaul section of the crown of the lower second primary molar was used as a standard. The cavity was conventional class II cavity. The restorative materials used were composite resin, silver amalgam and metal inlay.
The model of the class II cavity of the primary tooth was divided into 106points and 169 triangle elements. Displacement and stress figures were made, and the analysis was done for displacement of each point and the relative stress in the principal area.
The change in position of the tooth and the material at the mesial pit, peak mesial curvature of the tooth, axio-pulpal line angle and cervical marginal enamel were noticeable.
The degree of change in the position of restorative materials was low with resin, followed by amalgam and inlay. Furthermore, the deeper the proximal wall, the lower was the change. The stress in the restorative material in the occlusal portion was not related to the materials or to the depth of the proximal wall. However, in the proximal wall, the highest stress was found with the inlay followed by the amalgam and then resin. The deeper the proximal wall,, the more stress was concentrated in the bottom portion of the proximal wall.
The stress of the tooth was low with the inlay, followed by the amalgam and the resin. The differences in stress levels become incleasingly apparant when the depth of the proximal wall was increased.

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I have developed two new methods for accurate measurement of tooth eruption. One utilizes soft x-ray photography and provides lateral measurement along the curvature of an incisor and fixes standard points. The other, utilizing magnetic induction, allows continuous measurement of tooth eruption, taking into account respiratory and heart movement.
Using these two methods I have examined tooth eruption and the effects of anesthetics in rats and rabbits. In rats, a unilateral mandibular incisor was cut and the other left intact. The ratio of the eruption rates of the cut and un-cut incisors, determined by the soft x-ray phtographic method, served as an index of the response of proliferative basal tissue cells. Eruption was also measured in rabbits using an electromechanical appliance.
Both animals were anesthetized with Pentobarbital sodium, Ketamine hydrochloride and Urethane. Pentobarbital sodium and Ketamine hydrochloride did not influence the eruption rate, but Urethane markedly inhibited eruption. This is considered to be due to inhibition of protein synthesis rather than to anesthetic action.

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I have previously reported that Urethane inhibits tooth eruption. In this paper, Urethane was examined in more detail and compared with the other inhibitors, Mitomycin C, Carboquone,5-Fluorouracil, and Doxorubicin. Urethane inhibited tooth eruption in a dose-dependant manner, although proliferative basal cell growth response was not significantly influenced. There was a tendency towards recovery from the Urethane induced inhibition of the eruption.
Mytomycin C, Carboquone,5-Fluorouracil and Doxorubicin had the similar inhibitory effect to Urethane. The dose-dependant responses of Mitomycin C and Urethane were similar. The action of 5-Fluorouracil differed from that of Mitomycin C and Urethane, suggesting a different mode of action. There was no tendency towards recovery from inhibition with 5-Fluorouracil and Mitomycin C. Proliferative basal tissue cell growth response was also strongly depressed, except in the case of Urethane. These actions are considered to be due to the long acting nature and the stronger action on cell growth of these agents.

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The purpose of this study was to analyze the actual condition of the recall system in the pedodontic clinic of the Niigata University Dental Hospital, and to enable the recall system to be used efficiently. We investigated 3559 child patients (1907 boys and 1652 girls) who visited our clinic from September 1979to February 1984 for a period of 54 months and who had finished caries treatments.
Firstly, the following findings were obtained from each chart of patients;
1. The percentage of the first recall was 82%.
2. As the number of visits for caries treatments increased, the number of recall visits also increased.
3. As the patients adjusted to the dental procedures, the rate of the recall visits became lower.
4. Compared with the positive recall method, the rate of patients not visiting our clinic with the negative recall method decreased by three times.
5. Inside the prefecture of Niigata, the rate of recall had almost no connection with the distance between patients' homes and our clinic.
6. The rate of recall of patients using space retainers was high, compared with the rate of those using no space retainer.
7. The rate of recall of patients with some sort of systemic disease was lower.
Secondly, the following findings were obtained from the investigation of questionnaires. The questionnaires were sent to parents of 1221 patients who had not made the any recall visits at all.
1. More than 75% of parents answered that they did not consider further visits to our clinic as being necessary. Of those, the answer in which the children did not have any more dental caries occupied the highest rate.
2. In the group of patients under six years old, the rate of patients having visited the other clinics was higher than the rate of the group of patients over six years old.

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Dental Hospital since the opening on September 1979.
The style of treatment at our clinic is characterized by the following; the guardian sits beside their children during treatment, the restrainer is used for uncooperative children, and the mouth gag and rubber-dam are used as a general rule. We make every effort to relieve their anxiety and fear, e. g. encouraging and admiring the child, permitting the child to cry.
In the Pedodontic Clinic, it is important to gain the confidence of the guardians. Therefore, a questionnaire was made to find out how the guardians evaluate the style of treatment and whether they understand what we are trying to accomplish.
250 guardians were selected at random from the outpatients during the period from November 1985 to June 1986.85 children (66%) were in the recall group.
The questionnaires were summarized into three categories,1. background of visiting our clinic 2. evaluation by the guardians 3. influence of treatment on children and their guardians.
The following findings were obtained.
1.45.2% of all the patients was introduced our clinic by acquaintances.44%of all the guardians was motivated by the irfinding dental caries and gingival anomaly.134 patients had experienced dental treatment before visiting our clinic, and 30% of them could not be treated.
2. Sitting beside children and using the restrainer were evaluated highly, and our intentions were well understood. Though the use of mouth gag was supported by 83.2% of the guardians, the purpose of using this gag could not be precisely appreciated. The treatment with the rubber-dam was not well known. Though 74% of the guardians approved the use of the rubber-dam, this percentage was the lowest of the three (restrainer, mouth gag and rubber-dam).
3. As the treatments were repeated, the anxiety and fear of children tended to decrease. Even if children were crying, about 90% guardians desired the treatment to be completed fully. After treatment, changes in attitude was recognized in 30% of the patients (24.8% for the better,3.6% for the worse).

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The purpose of this study was to compare 3 methods of pit and fissure cleaning technique, and 2 types of sealant materials. Twelve extracted human premolars which were devided into 3 groups, and each group, consisting of 4 teeth, was treated with different cleaning techniques. Of each group,2 teeth were treated with chemically cured White Sealant, and the other 2 teeth were treated with light cured White Sealant.
After the thermal cycling test, these specimens were dyed with 0.5% basic fuchsine, sectioned, and then dyed again with 0.5 % methylene blue. The marginal sealing effect and penetration into pit and fissure of sealant material were observed and evaluated.
The results obtained were as follows;
1. In the teeth sealed with the chemically cured type of sealant, specimens cleaned with the air scaler had a greater frequency of marginal leakage than the others. The teeth sealed with the chemically cured type had a greater frequency of marginal leakage than those treated with the light cured type, and this was statistically significant.
2. The angle at the sealant margin, which was composed of the sealant and enamel surface line, tended to be wider in the teeth sealed with the chemically cured type than in those sealed with the light cured type.
3. No sealant material penetrated perfectly into deep narrow fissures. No significant differences existed among all groups with respect to penetration into pit and fissure of sealant materials.

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At the dental clinic of the Department of Pedodontics, School of Dentistry, Tokushima University, the emotional and behavioral reactions of children and the relationship between the behavior of the children and the personality factors of the children and their mothers were evaluated in 20 three-to-eight-year old children. The frequency of unfavorable reaction during the various kinds of dental treatment was evaluated in 26 three-to-eight-year old children.
The results are summarized as follows:
1. The younger the child was, the more the dependence on the parent. The dependence was evaluated with the “Taro-Hanako Personality Test”.
2. The personality of the child which was tested with “Taro-Hanako Test” did not correlate with the adaptability of the child to dental treatment. The age, sex of the child, being with or without their grandfather and/or grandmother, with or without brothers and/or sisters, and the personality of the mother which was tested with the “YG Test”, also did not correlate to the adaptability of the child to dental treatment.
3. It became clear that “Taro-Hanako Test” was unsuitable.
4. Ability to tolerate dental treatment did highly correlate to a talk with the dentist on the dental chair immediately before treatment.
5. Infiltration anesthesia, treatment of pulp, and dental electrical appliances had a high frequency of unfavorable reaction, and brushing of teeth, surface anesthesia, and oral examination had a low frequency.

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The relationship between the anxiety-trait of the mother and the personality of the child was investigated.70 one-to-thirteen-year old children and their mothers who visited at the Department of Pedodontics, School of Dentistry, Tokushima University were evaluated. The anxiety of the mother was measured with the State-Trait Anxiety Inventory (STAI) and the personality of the child was evaluated with the Takagi-Sakamoto Personality Diagnostic Test.
The results are summarized as follows:
1. The younger group of 3-6-year-old children was more “nervous”, experienced more “emotional instability”, and “maladaptation to the school” than the older group of 7-12-year-old children. The older group was more “selfassertive” than the younger group.
2. Correlations between “dependence” in the child and living with the grandfather and/or grandmother, and between “self-control”, “personal stability” in the child and the age of the father were recognized.
3. Correlations between “nervous”, “dependence”, “retrogress tendency” in the child and the anxiety-trait of the mother were recognized.

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The purpose of this study was to elucidate the morphological characteristics of the upper and lower dental arch of children with cleft lip and palate in deciduous dentition (Hellman's dental stage IIA), especially the influence to be seen in the lower arch and changes in the occlusional pattern.
The materials consisted of plaster models obtained from 10 bilateral and 30 children with unilateral complete cleft lip and palate (mean age, 3Y11M), who were operated on and treated by the Cleft Palate Team of Showa University.
For the control, plaster models obtained from 40 normal children (mean age, 3Y10M) were used.
The following results were obtained by three-dimensional analysis.
1) The influence of morphological and functional disorders caused by the upper dental arch with cleft palate was seen in the lower dental arch, mainly inclination or displacement of the lower deciduous teeth, and as a result changes of dimensions and asymetry of arch form were shown in lower arch.
2) All of the children with cleft lip and palate showed cross-bite, and in cases of unilateral cleft lip and palate cross-bite was shown more frequently on the cleft side than on the non-cleft side. As for the conditions of the terminal plane, a large number of children in the cleft group showed a mesial step type, but a great difference between the cleft side and the non-cleft side was observed. In many cases in the cleft group, the axis of the tooth crown of the upper and lower teeth showed lingual inclination in not only the anterior but also the posterior teeth.
3) on the vertical position of the upper and lower dental arch of children with cleft lip and palate, the vertical distance between the labial (buccal) marginal points of the upper teeth and those of the lower teeth varied remarkably in the anterior teeth, and children with cleft lip and palate showed more variable vertical distance in the posterior teeth than in the case of children..

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The purpose of this study was evaluate the clinical and microbiological effects candy containing palatinose on human dental plaque formation.
The teeth of fifteen subjects were cleaned by scaling and tooth-brushing preceding the experiment. They were then instructed to take food containing palatinose or sucrose for 3 days without tooth brushing. Thereafter, unstimulated saliva and plaque index scores were collected from all subjects.
The degree of dental plaque accumulation in those subjects who had taken food containing palatinose was significantly less than those on sucrose diet. On the other hand, the number of S. mutans in saliva was not influenced by the contents of palatinose and sucrose in the diet.
These findings thus suggest that palatinose is a low cariogenic sugar substitute for humans.

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Division of Pediatrics, Ogaki Municipal Hospital The Rubinstein-Taybi syndrome, originally described by Rubinstein and Taybi in 1963, is characterized by broad thumbs and toes, CHARACTERISTIC FACIAL FEATURES, mental retardation, short stature and various malformations. The syndrome has included some abnomalities in the dental area.
The case of a four year old boy, who was diagnosed as the Rubinstein-Taybi syndrome at the Pediatric Clinic, Ogaki Municipal Hospital, was refered to the Department of Pedodontics, Asahi Univ. Hospital for a dental examination. This patient was found to have typical symptoms associated with the Rubinstein-Taybi syndrome.
The dental findings, pertinent to this patient, were delayed eruption, retarded change in dentition, micrognathia, disfiguring of the dental arch and bifid uvula. A V-shaped dental arch in both jaws, cross-bite, as well as crowding of the anterior teeth were also noticed, but neither caries nor gingivitis were observed. The palate was generally shallow, but there was an inverted V-shaped hollow along the median palatine suture. Radiographic examinations showed enlarged dorsum sella, retarded bone calcification, and an enlarged distal phalanx of the thumb bone.

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The subjects were 1258 children who appeared at the Pediatric Dentistry Clinic of Nagasaki University Dental Hospital during the period from June 1983to December 1985.
The purpose of this study is to understand the actual condition and the state of the recall visit of the patients who appeared at our clinic, and to compare the results for each year.
Concerning the making of appointments for the recall visit, we did not send cards or make telephone calls to the patients so the patients themselves had to make a telephone call to arrange an appointment.
The results were as follows.
1) The rate of the patie nts who were making their first time recall visit was 41.6% on the average for each year. The rate of the patients who continued making recall visits for more than 2 years was 21.6%.
2) The average age of the patients was 5 years 7 months and the percentage of the patients aged from 3 years to 6 years was 50.8%. The lower the age of the patient, the high was the rate of the recall visits, while the rate of pre-school children was higher than that of school children.
3) The rate of the patients who spent under 1 hour for the visit was 65.8%. There was no difference between the rate of the patients who were making their recall visit and the time spent visiting the clinic.
4) When the patients were divided according to the motivation of the first visit to our clinic, the rate of the patients who made recall visits (51.4%) was highest when the motivation was that they were recommended to come by another patient of our clinic.
5) The rate of the patients who made recall visit was higher in cases in which the chief complaints of the first visit were tooth shape anomalies (62.5%), caries prevention (61.1 %) and swelling (52.6%) than the cases of tooth extraction (14.3%), trauma (22.6%) and tooth pain (28.1%).
6) The number of caries decayed teeth at the first oral examination was higher in the group for patients making their first recall visit (9.81 teeth) than in the group of patients rejecting a recall visit (8.76 teeth).
7) In the case of the patients to whom space retainers and orthodontic appliances were applied, the rate of making recall visits increased over the years and the rate in 1985 was 74.5%.
8) The number and the rate of generally diseased children were 229 (18.2%). There was no difference in the rate of those making their first time recall visit between generally diseased children and non-diseased children. However the rate of patients who were operated under general anesthesia or sedation and made recall visits increased over the years and the rate in 1985 was 75%.

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Reflecting the complexities of modern society, the number of various diseases, syndromes, and new diseases is on the increase. There is an increasing number of times when a dentist will encounter cases which are not specifically covered in the textbooks so that he has to refer to special reference books for help. In order to cope with this situation, at present, the data base computer system is being used in the field of dentistry for collecting, scanning, changing, and supplementing the data. It is generally felt that this is the best and most valuable way to accumulate data.
This present study was conducted to assess the value of using the computer system for aide in diagnosis and for searching out congenital diseases, especially in the field of pedodontic dentistry. This particular data base system does not require complex programs and it is possible to input data, edit, search for, and print out the data, with the required information being available immediately. For these reasons the computer was found to be very effective as an aide in diagnosis.

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We experienced a very rare case of constitutional erythroid hypoplasia (Josephs-Blackfan-Diamond type) with immunodeficiency. The patient was a girl,8 years old at the time of the first visit. She had been given adrenocortical hormones since she was 3 months of age. Her physical and mental growth was very noticeably retarded for her age.
A blood analysis revealed that she had already recovered from the anemia (hemoglobin 13.6g/dl, hematocrit 41%), but measurable amount of the immunoglobulins could not be found in every class. In an analysis of the surface antigens of the lymphocytes using the monoclonal antibody, the ratios were as follows.: OKT3 90%, OKT4 35.4%, and OKT8 52.2%.
The chief complaint was a spontaneous pain of the right lower first molar. An oral examination revealed seven deep cavities. Oral hygiene was poor, but her gingiva and oral mucosa were not so unhealthy.
Because of lack of cooperation concerning the dental treatment procedures on the part of the patient, due to her mental retardation, we performed intensive dental treatment under general anesthesia.
Since then, her dental health has been satisfactorily maintained under the periodical dental check-up system of our hospital.
At 9 years 8 months of age (1 year and 10 months after the first visit), a lateral roentgenographic cephalogram analysis was performed. The denture pattern was almost within normal limits, but hypoplasia of the maxilla and the mandible was recognized. A radiograph of the wrist revealed a remarkable retardation of the bone maturational stage. A model analysis showed significantly small values on the upper and lower dental arch width.
These growth retardations seemed due to the side effect of the long term use of the adrenocortical hormones.

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1. Four cases of submandibular sialolithiasis in child patients with ages ranging from 6 to 8 were reported on.
2. The findings of the cut surface of the salivary caluculi with SEM revealed a similar structures among the four cases.
3. The findings of the salivary calculi in children showed many structures similar to those in adolescents and adults found in the literature.
4. It was indicated that bacteria participated in the formation of salivary calculus in children.

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Möbius syndrome is an extremely rare neurological disorder and its salient features are facial and abducens palsy, usually bilateral. Other cranial neuropathies, hearing loss, ossicular adnormalities, malformed pinnea, micrognathia, and limb defects, have been associated features in 1% to 15% of the cases in the previous reports.
A case of a two-year-old boy with Mobius syndrome, mild-moderate mental retardation is described in this report.
The patient was born after 40 weeks. The birth weight was 2774 g. The family history was negative with respect to any congenital deformity. During the first 8 months of life the boy suffered from severe sucking difficulties. He had facial and abducens palsy and also had a left-sided malformed pinnea. The feeding difficulties remained, but gradually became somewhat less severe. He did not show any contact smile and his gaze was very “stiff”. He had speech, language and hearing problems. He could not walk without support.
All his erupted deciduous teeth were attacked by severe dental caries. The upper and lower deciduous second molars were unerupted. From the panoramic roentgenogram, congenital missing of lower left and right lateral incisors was doubtfull (not seen). Furrowed tongue was observed.

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We conducted a survey to investigate the actual state of the dental treatment needs of the handicapped subjects by distributing questionnaires to nurseries for pre-schooling age children, special schools for the handicapped, welfare associations and vocational training institutions for post-schooling age persons.
The results of the survey were as follows:
1) Regular dental examinations were performed in 78% of the nursery schools,93% of the special schools and 45% of the post-schooling educational institutions. Parents were informed of the results of the examination and given advice for treatment by all institutions except those for the post-schooling age persons.
2) School dentists or contract dentists were present in 65% of the nursery schools,96% of the special schools and 23% of the post-schooling educational institutions. About 60 to 70% of all the dentists carried out preventive work and about 50% of them were positive in treatment.
2) As for institutions receiving dental treatment, the nursery schools relied mostly on dental specialists for the management of the handicapped patients while other institutions preferred general practitioners.74% of the nursery schools,71% of the special schools and 73% of the post-schooling education al institutions received dental treatment from voluntary medical and/or general dental practitioners.
4) The number of decayed teeth was low in nursery schools while the number ranged from 5 to 10 in about half of the special schools and the post-schooling educational institutions. The frequency of dental visits was high among children from nursery schools but generally low for those coming from other institutions.
5) Tooth brushing after lunch and tooth brushing instruction were done in about 70-80% of all the institutions. The state of oral hygiene was rather good for the nursery school children but poor for more than half of the handicapped subjects from other institutions, especially those who had mental retardation.

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