This study is a part of the report on dental care of handicapped children and adults that was commitioned by the city of Tokyo in 1982.
First, we will examine the oral health program for handicapped children. We investigated as a fundamental study of the rehabilitation of the oral functional disorder as a part of a total study to clarify the degree of the oral functional disorder and the relationship between the degree of the oral functional disorder and development of the general function.
We obtained the following conclusions:
1. The degree of oral functional disorder of children with a severe oral functional disorder was 52.5% and the most severe disorder among oral functions was speech which has no effect on life support, what was slightly effected was the symetry of the lips and face and the formation of the head.
2. The actual degree of the functional disorders tended to be at the same level. Those disorders which showed a particulary severe degree of disorder were maintnance of posture, stationary state of the jaw, lifting of tongue, swallowing, and drooling.
3. Comparing the degree of oral function disorders with the development of the general functions we found that the degree of oral functional disorder was lighter than the developmental retardation of the general functions.
4. We found that the development of the oral functions had a high relevance to the development of the general functions, especially the maintenance of posture had a high correlation with the development of personal relationships, daily life, utilization of utensiles, understanding and walking.
5. If the neuromuscular relationship between them could be physiologically clarified and therapy created to promote the development of oral functions, it was shown that the promoted result of development of the oral functions has the potential to be able to promote development of the general functions.

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The subjects were 95 handicapped children (51 boys and 44 girls), who visited Takamatsu Dental Emergency Center from 1980 to 1982 for dental care. Their ages ranged from 4 to 17 years.
The subjects were classified into 6 groups according to their disorder: the MR Only Group, the CP Group, the Down Group, the Autism Group, the Epilepsy Group and the Other Group.
Items such as the caries attack condition, the means of treatment of the caries, the mean number of times the children visited center, the mean number of recall, the means of treatment at recall time, and the answers to qestionnaires were investigated.
The results obtained were as follows:
1. The caries positive rate was 94.3%, which was not much different from the rate of ordinary children, and the df tooth rate was 28.5%, which was lower than that of ordinary children (36.9%).
2. At the center,25.3% of the caries teeth was treated with application of diammine silver fluoride solution, and 20.3% was treated with composite resin filling. There rates were higher than those of other means of treatment.
3. The mean number of times children visited center was 7.3 in the MR Only Group which was followed by the Autism Group,6.7. The number of times from the first visit to the attainment of acceptable of dental treatment was 2.1 in the MR Only Group which was the highest, and was 1.3in the Epilepsy Group the lowest. The mean number of recalls was 0.7. Most procedures at recall time included brushing instructions and fluoride application, but a few included restoration, endodontic treatment, etc.
4. The results of qestionnaires at the first visit were as follows. About 70% of children had suffered from tooth pain (20.0%), caries (17.9%), and other problems (35.8%). About 50% of the children had visited a dental office and half of them had been able to obtain treatment. The number of children who brushed their teeth was 72 (75.8%), had normal meals was 88 (92.6%), ate snacks between meals regularly was 55 (57.9%).12.6% of children had the oral habit of bruxism.

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Biomechanical instrumentation of the root canal is one of the most important phases of root canal treatment. There are several articles on scanning electron microscopic study of the root canal walls of permanent teeth after endodontic procedures. However, there are no reports on deciduous teeth.
In this study, the effectiveness of the instrumentation and irrigation of the root canal of deciduous teeth was evaluated by means of scanning electron microscopy.
The root canals of nine recently extracted and single rooted deciduous teeth were prepared. Each of the root canals was instrumented in vitro according to accepted clinical procedures through the crown of the tooth with K-type files (Zipperer), H-type files (Zipperer), or Diamond files (Kerr). The mechanical instrumentation was always followed by the combination irrigating procedure using sodium hypochlorite and hydrogen peroxide by means of a syringe. Final irrigation was performed with distilled water. On completion of instrumentation and irrigation, horizontal and longitudinal cuts were made on the cervical line, half length of the root, and the labial and lingual surfaces. Each root was split into four sections (crown side-mesial section, crown side-distal section, apex side-mesial section and apex side-distal section). The hemisections of the crown side and the apex side were not treated with an ultrasonic cleaner. The other sections were rinsed with an ultrasonic cleaner.
Each section was examined by scanning electron microscopy.
The results obtained were as follows
1. The standard instrumentation techniques produced a canal wall that had uninstrumented areas.
2. The canal wall was smeared with dentin mud. Dentin tubules were not observed due to the smeared layer. The canal wall of apex side was smeared with dentin mud and packed with debris.
3. The irrigating procedure commonly used in endodontic practice was not effective in removing the smeared layer. Ultrasonic cleaning also was not effective.
4. Among the use of K-type files, H-type files and Diamond files, no different effects were observed.

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For effective prevention of dental caries in infants in some localities, it is necessary that we are aware of the nursing environment including nursing methods, dietary habits, tooth brushing habits, and so on, in those localities.
On the basis of the questionnaires to the mothers of 267 infants at the age of one and a half years in the same area, the nursing environment was investigated.
The results obtained were as follows:
1. Of the mothers,36.7% were employed, and about 70% of them were full-time employees.
2. Of the children, about 24% till 6 months after birth, about 27% from 6 months till one year, and about 30% from one year till one and a half years were reared by their grandmothers through the daylight hours.
3. Of the means of feeding, bottle feeding was 41.6%, mixed feeding was 28.1%, and breast feeding was 22.5%. The rates of irregular suckling, suckling a baby lying on the bed, and delayed start and completion of weaning were higher than in other localities.
4. A great number of mothers of infants who had breast or bottle feeding habits while sleeping answered that they did not think it was wrong.
5. More than 50% of the infants ate between-meal snacks, irregularly.
6. The rate of regular tooth brushing was very low,16.9%.

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In recent years, tooth-to-benture-base discrepancy has been attracting the attention of dentists as a factor that influences malocclusion and other oral deseases. However, there are still doubts concerning the reliability of the relationship, because, although many reports in regard to the relation between the discrepancy and the oral disease were investigated with the measured value in accordance with the methods of Tweed, whether this measurement is proper to epidemiological evaluation of the discrepancy is questionable.
The present study was aimed at solving this question.
The data were taken from the dental casts and Roentogen ographic cephalograms of 132 school children at the stage of permanent dentition.
The results obtained were as follows:
1. The interrelationship between the measured values in according to the method of Tweed and the severe scale of crowding showed a higher correlation coefficient than the other interrelationships.
2. The numerical value that was measured with Tweed's method, except that of the Head Plate Correction (A. L. R. A. L. ) also accurately evaluated the clinical the irregglarity of permanent dental Arch.
3. The Spee Cqrve, over bite and over jet expressed the minor clinical malocclusion in relation to the tooth-to-denture-base discrepancy.

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A premature loss of deciduous molars is one of the problems in the dental health program for the deciduous and mixed dentition period.
In recent years, there have been reports that the effect ofprematqre loss of deciduous molars on the developmental malocclusion in permanent dentition was determined by the tooth-to-denture base discrepancy. The reports are very important for the dental health management at Pedodontic clinics.
The present study was aimed at confirming the reports in regard to hte relationship between tooth-to denture-base discrepancy and malocclqsion.
The data were taken from the longitudinal dental casts of 300 school children who were surveyed over a period of seven years, and Roentogenographic cephalograms at the stage of permanent dentition.
The results obtained were as follows:
1. A significant relationship between the premature loss of secondary deciduous molar and the sever scale of the irregurality of permanent dental arch was not found.
2. The migration patterns of the first permanent molars were not significantly related to premature loss of secondary deciduous molars and the measured value in accordance with the method of Tweed. Also it could not be considered that the mesial migration of the first permanent molar principally caqsed the irregurality of the permanent dental arch.
3. The significant relationship between the sever scale of irregurality of the dental arch and the measured value according to the measurement with the exception of the Head Plate Correction from the method of Tweed, (A. L. -R. A. L. ) was found.
4. A significant relationship between a status of craniofacial (ANS-ptm, A'-ptm', S'-ptm' and pog-GO) and the severe scale of the irregurality of the permanent dental rch was found. It was suggested that the effects of premature loss of deciduous molars on the development of malocclsuion in the permanent dentitin were small, and were determined by tooth-to-denture-base discrepancy, based on a mass evaluation.

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Composite resin full crowns which use composite resin and crown forms, had been used for restoration or 87 primary anterior teeth of 2 to 9 years old children, were observed clinically and microscopically and evaluated. Postoperative observation periods were from 30 to 1480 days, and averaged 496 days. Clinical observation was conducted by means of an explorer, X-ray and colour photography.
The following clinical findings were obtained.
1. Dislodgement of crowns 5 cases (5.7%)
2. Breakage of crowns 8 cases (9.2%)
3. Aburration of crowns 15 cases (17.2%)
4. Discolouration of crowns 5 cases (6.9%)
5. Gingivitis 2 cases (2.3%)Marginal adaptation of the composite resin full crowns was observed clinically in 6 cases of exfoliated teeth, and 3 cases were evaluated as good,1 case as fair and 2 cases as poor.
Marginal adaptation of the crowns was also observed through the scanning electron microscope and revealed that the adaptation was not always good. As a result of this experiment the following conclusions were obtained.
A composite resin full crown has maximal esthetics, easy to fablicate in minimal chair time, and also has better clinical results than that of the conventional resin jacket crown.
It is considered that a composite resin full crown results in suitable restoration for primary anterior teeth.

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This study was attempted in order to investigate the tooth-adhesive resin penetration into the etched normal and carious primary dentin through a scanning electron microscope. Extracted or exfoliated teeth (noncarious: 84 cases, caries extended into the dentin: 26 cases) were used. Cavities were prepared dry with the diamond bars, softened dentin was removed with the steel bars and a hand instrument. The commercially available resins used in this study were Adaptic, Silar and Clearfil F. The dentin was etched for l minute, then rinsed with water for 30 seconds and desiccated with compressed air for 30 seconds. The following observations were obtained.
1. Using the bonding agents, the length of the resin tags into the carious decayed dentin is shorter than that into the noncarious dentin. Also the length of the resin tags into the carious decayed dentin with bonding agents is almost the same as the resin tags into the noncarious dentin without bonding.
2. The shape differences of the resin tags were variable between noncarious teeth and carious decayed teeth, and also according to various commercially available resins.
3. Clearfil F showed the best penetration into the dentinal tubles.
4. The resin penetration into the carious decayed primary dentin was lower than that into the normal primary dentin

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The basic principles of infected root canal treatment in deciduous teeth are considered to be the same as those for permanent teeth removal of root canal contents and enlargement of the root canal for filling. However, it is true that the treatment of the deciduous root canal is more difficult than that of the permanent root canal because of various restrictions arising from the anatomical and physiological characteristics of deciduous teeth. Therefore, in this study, the propriety of the iontophoresis as a more successful method for root canal treatment was investigated. In particular, deciduous root resorption, harmfqlness to permanent successors, and effects on the eruption process were roentgenographically as well as microradiographically observed. Iontophoresis was performed in young dogs with deciduous molars using ammoniacal silver solution, iodine and zinc iodine solution. From the regular periodical investigations, the following conclusions were drawn.
The resorption of deciduous roots whose canals were filled after pulp extraction showed a tendency to retardation irrespective of whether iontophoreisi was performed or not. However, there were no significant findings which suggested the effects of iontophoresis on the resorption retardation. Concomitant with the retardation of root resorption, a tendency to retarded eruption of permanent successors was observed, while the uuantity of the formed dental germ remained unaffected. After natqral shedding of deciduous teeth, it was found that the permanent successors on the treated side showed a tendency to overtake those on the control side. Iontophoresis, which has, as mentioned above, no effect on formation and eruption of permanent successors when applied to the deciduous root canal treatment, is thought to be free from danger when applied to the cndodontic treatment of deciduous teeth.

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The purpose of this paper was to discover the relationship between the caries prevalence of the pre-school children and the salivary concentration of Streptococcus mutans using the semi-quantitative determination method (MSBB). In this method, the salivary concentration of S. mutans was showen as the degree of the adherent bacterial colony classfied score -, +, _??_ and _??_, and the resqlts of MSBB was compared with those of another test, CARIOSTAT.

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As a resolt of a commission by the Tokyo municipal Goverment, dental examinations of mentally and physically retarded children at home and interviews with their mothers were made to investigate the relationship between dental diseases and the severity of the disturbed oral function in the hope of establishing methods for restoration of the disturbed masticatory function and prevention of dental diseases in such children. A total of 48 children with the average age of 3 years and 8 months were studied, as with Part 1, and those included 30 who went to a branch of the Tokyo Mqnicipal Kita-Ryoikuen at Johoku and 18 who consqlted the outpatient clinic.
(1) Child patients showed a state of caries similar to that of normal children, sqggesting a smoller relationship between the severity of the disturbed oral function and the occurrence of caries.
(2) The severity of the disturbed oral function is generally considered to be a major factor in affecting the development of caries. It is assumed, however, that the occurrence of dental diseases in younger children is mostly dependent upon the extent of the knowledge of prevention of dental diseases whitch guardians such as mothers have and the level of oral hydgiene.

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Tumor doubling time, that is, the time reuuired for tumor volume to become twice as large, was calculated using Gerstenberg's formula.
While histouathological referrals are ideal for diagnosis, observation on growth rates of the lesion by radiographs is interpreted as painless to the subject and useful for differentiation of benign and malignant tumors.
We recently studied patterns of calcification of the mandible in four pediatric outpatients and obtained measurment of these calcified lesions as seen on orthopantomographs by means of a computerized suuare-measurement system for indeterminate forms.
The mean value of the doubling time in this study was 9.9 months, which differed considerably from that of malignant tumors.
In addition, we found that size of the lesion is related to the growth of the individual.

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In cases of traumatized young permanent incisors, the frequency of luxation is high, and the development of splinting methods in recent years has preserved more of these teeth. The present study is a clinical and radiographic investigation of 66 luxated young permanent incisors.
The mean observation period was 2.5years. The results are summarized as follows.
1) Obliteration of the pulp cavity was found in 25 teeth, and pulp necrosis was found in 8 teeth. Obliteration was found mostly in periods of observation under 1 year. Pulp necrosis was found mostly in periods of observation about 1 month.
2) Obliteration of the pulp cavity occured more frequently in teeth with partially developed roots, and pulp necrosis more in teeth with fully developed roots.
3) Dividing the prognoses of these teeth by the type of luxation, good cases were found more frequently among concussion and subluxation, pulp obliteration cases were among extrusion and lateral luxation, pulp necrosis cases were among intrusion.
4) Anomalies of the root development were found in 33 cases, and 2 of them seemed to be ankylosis teeth.

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The purpose of this study was to observe the change of the position of the maxillary and mandibular permanent central incisors after emergence into the oral cavity as seen from the occlusal position.
Six-hundred and thirty seven dental casts were obtained from forty children, twenty one boys and nineteen girls, with normal occlusion. Casts were taken at six months before shedding of deciduous central incisors and were taken every 2 months during the first year after emergence of the central incisor.
The outlines of the central incisors from occlusal views of the casts were traced using five-fold magnification by means of a Nikon V-16A profile projector. Lines of reference were made among the distal contact points of both, right and left deciduous canines. Distances from the incisal edge to the line of reference and the 767angle formed of incisal edge with relation to the midline were measured and analyzed by computor.

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The purpose of this study was to investigate the effect of pit and fissure irrigation. using the GK-101 solution and the originally designed scratch point prior to application of sealant for removing the contents from the incipient carious pit and fissure of young permanent teeth.
Forty-four human premolars stored in the freezer immediately after extraction were divided into the experimental group (22 teeth) and the control group (22 teeth). The teeth of the former group were irrigated using the GK-101 solution and the scratch point, and those of the latter group were irrigated with the conventional method.
At first, the longitudinal ground sections were prepared buccolingually from the fissure area of nine teeth each of the both groups, and stained with acid red for examination by light microscopy to evaluate the effect of the GK-101 irrigation.
Topography of the fissures was classified to the shallow, wide, V-shaped or U-shaped fissures considered to be easy to clean, and the deep narrow club shaped fissures considered to be difficult to clean with the conventional method. The V- or U-shaped fissure, having stained remnants of the fissure contents, was designated as irrigation negative, and that having no remnants was designated as positive. The club shaped fissure from which the contents were removed down to their undercut area was also designated as positive, that having the contents up to the narrowest constriction was designated as questionable, and that having contents remaining over the constriction area was designated as negative.
Subsequently, five teeth each of both groups to which the sealant was applied, were sliced into ground sections to evaluate the degree of impregnation of the sealant into the pit and fissure. They were also classified by the shape of the fissure, and the same criteria were used for the evaluation.
For the third experiment, eight paired first premolars obtained form the same individuals were used for examination of the tag formation of the sealant by means of scanning electron microscopy. One of each pair of the experimental group was irrigated using the GK-101 solution and scratch point. The remaining teeth were divided into two groups, which were control group I and control group II. The teeth of control group I (4 teeth) were conventionally irrigated using brush corn, and those of control group II (4 teeth) were irrigated using distilled water and scratch point. They were, then all treated with sealant, and exposed to 10%nitric acid solution to prepare resin replicas showing the inner surface of the applied sealant for the SEM exanination.

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1. The authors experienced Epulis granulomatosa in the labial gingiva at A in a 9-month-old boy, the occurrence of which is regarded as comparatively rare by age and by incidence rate.
2. Pathohistological investigation revealed proliferation of granuloma accompanied by significant inflammatory cellular infiltration. In the lamina propria, several nervous bundles were creeping in portion and degeneration of nerve fibers with swelling and laceration of axon was concurrent.

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