Pit and fissure sealing with fissure sealants was performed on 221 C₀ and C₁ in 98 young outpatients, aged 2 to 12, visiting the Department of Pedodontics, Kyushu Dental College. The condition of the sealing was investigated for one year clinically through a scanning electron microscope.
The results were as follows:
1. The rate of retention of the sealants averaged 91.8%.
2. Based on scanning electron microscope, the main cause of the detachment of the sealants was attributed to insufficient etching and the resulting lack of adhesiveness.
3. In the cases of good retention, the transitional zone between tooth substance and sealants was very smooth regardless of the number of days elapsed.
4. Morphological remineralization of the etching surface appeared to be completed in 6 to 7 months.
5. On the basis of the foregoing, fissure sealants appear to be sufficiently practical and effective in clinical application.

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“Vitapex” is a root canal filling material which is composed of 33.3% calcium hydroxide,22.4% silicone,40.4% iodoform and others. It is widely used not only for permanent teeth but also for deciduous teeth because of its ease of handling and good clinical prognosis. This material used in the root canal is said to be resorbed in accordance with the root resorption of the deciduous teeth but whether it can be removed by the body is unclear. Silicone, which is a most biocompatible material used in the field of constructive operations does not seem to be resorbed and discharged by the body. The present study was undertaken to decide whether the disappearance of the root canal filling material on the X-ray photo meant the real disappearance of the material or not.
We implanted the root canal filling material in the dorsal subcutaneous tissue of rats and took X-ray photos regularly. The implanted material was collected and its silicone content was checked using infrared spectroscopic analysis and nuclear magnetic resonance analysis.
The following conclusions were demonstrated in this study.
1. Although “Vitapex ” lost its radio opaqueness within 2-3 weeks after implantation, silicone containing residues of “Vitapex” remained in the implanted area. This result means that the disappearance of radio opaqueness in X-ray photos does not necessarily involve the disappearance of the material.
2. The quantitative analysis indicated that almost 100% of the silicone in “Vitapex” remain ed at the implanted area even after 3 months.
3. Calcium carbonate was detected in the residue of “Vitapex” 2 weeks after the implantation but calcium hydroxide, one of the ingredients of the “Vitapex” could not be found. This fact suggested that calcium hydroxide in the “Vitapex” was neutralized to calcium carbonate in the subcutaneous tissue.

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The purpose of this study was to investigate the characteristics of Down's syndrome in relation to development of the teeth and the body. The subjects were 48 children with Down's syndrome (30 boys and 18 girls). Categorised by the karyotype of chromosome,43 were of the trisomic type and 5 were of the mosaic type, the children with the mosaic type all being boys. The age of the subjects ranged from 9 to 42 months. The age at the time of the eruption of the deciduous teeth was determined with semilongitudinal every 3 months data and the mesiodistal diameters of the crown of the deciduous teeth were measured on the plaster model. Above mentioned results were transformed into the standard scores. In the same manner, the data concerning the heights and the weights recorded at the same time were transformed into the standard scores. The following results were obtained;
1) Regarding all types of the teeth, the age of the eruption was delayed about 2 to 10 months longer in cases with Down's syndrome than in normal cases (Okamoto,1934), and delayed eruption especially was more evident in the anterior teeth than in the posterior teeth.
2) Regarding the dimention of the mesio-distal diameter of the crown, except for the lower lateral incisor and the lower second molar, the standard scores of all the other teeth were larger than those for the teeth in cases without the syndrome (Ono,1960). This means that the dimentions of the mesio-distal diameters in cases of Down's syndrome were generally larger than in cases without the syndrome.
3) The effects of the karyotype of Down's syndrome on the eruption were evident (p<.05), but statistically not on the height and weight.
Our results suggest that the investigation of the development of the deciduous teeth throws some light on the resolution of the developmental problems of Down's syndrome.

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[in Japanese]

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Clinically, occlusal equilibrations are conducted for children with functional occlusal interferences to improve the occlusal relationship. However very few studies regarding to the neuromuscular effects after occlusal equilibration have been ever made.
The purpose of this study was to examine the influences of occlusal interferences on masticatory muscles and to evaluate the effects after occlusal equilibration electromyographically. Eight children, including six with deciduous dentition and two with mixed dentition were the subjects, all of whom had shown unbalanced EMG activities of the temporal muscles on the tonic neck reflex elicited by dorsal flexion of the head. All of them manifested occlusal interferences clinically during the movements of mandible. On the other hand, nine children found to have functionally normal occlusions with the deciduous dentition were selected as a control.
The results obtained were as follows:
1. The analysis made on the model disclosed that six children out of 8 exhibited an asymmetrical relationship of the occlusion at the canine compared bilaterally and the rest of the children showed a symmetrical relationship.
2. The grade of overbite and overjet found in the occlusal equilibration group was greater compared with that of the control group.
3. As far as the ratio between mandibular arch vs. maxillary arch in terms of intercanine distance and arch length is concerned, it was smaller in the occlusal equilibration group compared with the control group.
4. The occlusal interferences were most commonly observed at the region of the deciduous canine.
5. After the occlusal equilibrations were conducted, six children were found electromyographically to have improved, but in the rest of children, hypertonicity in masticatory muscles still remained.

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A clinical statistical study on 180 traumatized teeth of children between 1974-1983 was conducted in the Pedodontic Department, Gifu College of Dentistry.
The subjects comprised 100 children (0-15 yrs of age). The reports served as a basis for analyzing the age, sex and monthly distribution, location, the number and type of injuries and its treatment, causes for the trauma and the time elapse from the time of injury to the initial treatment.
The results were as follows;
1. The most frequent incidence of injuries was found in the children between 1-2 years of age, and the rate of incidence was 39.0% of all affected teeth. Boys suffered almost 1.7 times as many injuries as girls did. The injuries occured more frequently during April to May and October to November.
2. Dental injuries usually affected 1 to 3 teeth, and maxillary central incisors were most frequently affected both primary and permanent dentition.
3. Crown fracture and luxation, including subluxation exarticulation, were the most common type of dental trauma. The choise of the treatment for the injured primary teeth in order was immediate extraction, observation, pulp treatment and placement of splinting. For the permanent dentition, pulp treatment, placement of splinting, replantation and extraction were preferred.
4. The main causes for trauma were by collision and by falling.
5. Most children with the dental injuries visited the dental clinic for emergency care within serveral hours after injury or else on the day after.

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In recent years, there has been an increased trend towards starting pedodontic and orthodontic treatment during the early mixed-dentition period. Before a clinical diagnosis and plan of treatment can be made, it is essential that the pedodontist and orthodontist have an accurate method of predicting the sizes of the unerupted lower canines and premolars. As Nance has indicated, this arch is used as a reference point in most prediction analyses for successful mixed-dentition predictions focus on analysis of the lower arch.
It is the intent of this article to compare the accuracy of some of the more popular prediction methods. The methods in question include those of Ono, Moyers, Hamano, and Hirata.
Study casts were taken from a sample of 45 children (23 males and 22 females), born and reared in Yamagata city, Yamagata prefecture in the Tohoku area (northeast area) in Japan.
The result were obtained as follows:
1. When the absolute values of errors between predicted values and actual values, as a standard to compare the accuracy of prediction methods, were used in this article, it was found that the method proposed by Hirata was more accurate.
2. The histograms of the absolute values of errors between predicted values and actual values of each method indicated tendencies towards a minus quantity.
3. The regression equations between predicted values and actual values of females of each method indicated high tendencies of agreement of those.

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For the purpose of the investigation of the fine structure of the dendritic cells of the gingival epithelium of children, a total of 40 subjects ranged from 4 to 12years of age were observed by using the ultrathin section method.
The following results were obtaind.
1) Melanocytes were found in the basal and the lower spinous layer of child gingival epithelium, and Langerhans cells were observed in the spinous layer.
2) Many melanosomes and premelanosomes with varying developmental stages were observed in the cytoplasm of the melanocytes. The fully melanized ovoid melanosomes were measured to be about 0.3 by 0.1μm.
3) Most of the melanosomes which moved into the keratinocytes were observed as a single glanule, but a few small melanosome complex were also seen. The number of melanosomes in a keratinocyte showed a tendency to increase with aging.
4) The ratio of Langerhans cells to gingival keratinocytes was considered to be smaller than those to epidermal keratinocytes.
5) Some of the dendritic cells lacking the charactristics of melanocytes or Langerhans cells were observed in the basal layer of the child gingival epithelium. It was suggested that these cells were molphological inactive melanocytes.

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It has been reported (Moyers) and generally recognized that the sucking reflex in a new born baby would develop into chewing in accordance with the eruption of the incisors. The perception acquired at the periodontal membrane of the deciduous teeth may be assumed to play a role in the transition from the sucking reflex into chewing. The purpose of the present study was to clarify the possible role of the perception of the periodontal membrane on the development of chewing in new born puppies with the aid of electromyograms.
Fifty puppies were used and divided into four experimental groups as follows;
1) Control
2) Enucleation of all tooth-germ before eruption of the deciduous teeth (Enucleation group)
3) Nerve block before eruption of the deciduous teeth (Block group)
4) Extraction of all teeth after eruption of the deciduous teeth (Extraction group)
The electromyograms of temporalis and masseter muscles were recorded with needle electrodes (RBL-85, Nihon-Koden Co., Tokyo, japan). The transitional time from the sucking reflex into chewing was assessed either by the sensation of the index finger inserted into the mouth of a new born puppy, or by electromyogram activities of the masticatory muscles.
The results obtained in the present study were as follows:
1) Normally, as observed in the control group, the time of the transition from the sucking reflex into chewing and the formation of chewing cycle occured simultaneously when the puppies were 20.1 days old. The time was precisely related to the eruption of the deciduous incisors (22.3 days of age).
2) In the enucleation group, the time of the transition was evidently delayed about 7 days, and chewing cycle did not developed till 60 days of age.
3) In the block group, chewing was delayed 4 days, although the chewing cycle was not noticed just after the beginning of chewing, it emerged afterward at the 49.0th day of age.
4) In regard to the chewing cycle as was examined in the extraction group, about 6 days were required after the extraction to catch up to a similar chewing cycle observed before the extraction.
From the results obtained in the present study, it was concluded that the eruption and presence of deciduous teeth has an important role in the development from the sucking reflex into chewing, and on establishing the chewing cycle. Also it may be assumed that the impulses given to the periodontal nerves of deciduous teeth may play the possible role of a trigger to a neural switch mechanism from sucking reflex into chewing, and also give stimulation to develop the central chewing rhythm generator.

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The biocompatibility of pure nickel, two types of deciduous crowns, and the distal-shoe, which have been applied in pediatric dentistry, were evaluated histopathologically and biochemically, and the subcutaneous tissue of experimental rats were used in this study.
The macroscopical observation revealed that the tissue around the nickel had shown severe inflammatory changes accompanied by swelling and redness. On the seventh day of the experiment, histopathological examination revealed that these masses showed the following findings; a necrotized tissue in contact with the nickel, a severe inflammatory tissue layer with inflammatory cell infiltration, a narrow bleeding layer, and a network-structure of fibrous tissue with numerous capillaries. The tissue had been gradually affected by the nickel. After ninety days, eosinophilic amorphous masses were seen around the nickel, which was surrounded by granulation tissue and connective tissue layers with numerous inflammatory cell infiltration and capillaries. A large amount of Ni²⁺+ was detected in the subcutaneous tissue around the nickel metal in all of the experimental animals. The tissue around the two deciduous crowns and the distal-shoe showed that the almost all of the experiments did not reveal any gross changes nor did the histopathological findings.
The tissues around the metal were composed of fine fibrous tissue layers without inflammatory cell infiltration and granular foci, which revealed good biocompatibility. A small amount of Ni²⁺+ was, however, detected in the tissue around these metals.
These findings have indicated that the alloys were corroded, and the nickel had been released from the alloys as Ni²⁺+ or Ni compounds and Ni²⁺+ remained in the tissue without any changes.
These experimental studies have shown that nickel as a metal would cause of serious inflammatory reactions in the tissue. Although the tissue is not affected by the alloys, a small amount of Ni²⁺+ could be detected with the atomic absorption method.

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To observe the longitudinal changes in Life Style with the same individuals after they had undergone dental health examination at one year and six months of age, we examined the state of weaning, between-meal snacks, drinks, and tooth brushing.
The subjects were 266 children who visited the Health Center in Ohta Ward in Yokyo at six months intervals from one year and six months of age to three years of age.
The results were as follows.
1) Although weaning should be finished at one year and six months of age,44.7%of the children continued breast feeding or using the nursing bottle. However later, by age two most of them had finished breast feeding or using the nursing bottle.
2) Concerning between-meal snacks,44.4% of children consumed snacks regularly at one year six month of age. Later the number of those who consumed snacks regularly showed a tendency to increase according to age. We surmised that those who consumed snacks regularly continued doing so. The number of those who consumed sweets increased according to age, especially from one year and six months of age two years of age.
3) Concerning the intake of drinks,32.7% of children took drinks regularly in addition to water and tea at one year and six months of age. Later, there was no noticeable change. The number of those who drank milk chiefly increased according to age, those who often drank a great deal of sweet drinks decreased according to age.
4) Over 70% of the children had started tooth brushing, but few practiced tooth brushing everyday at one year and six months of age (37.3%). After the dental health examination, most of the children started tooth brushing everyday.

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This report is a study, the purpose of which is to aim at systematizing a clinicalphysiological diagnotic standard for the TMJ dysfunction syndrom in adolescents. The subjects were 5 patients with the occlusal TMJ dysfunction syndrom aged.13-19 (3 boys and 2 girls) who were relieved of the symptoms by means of an occlusal splint and occlusal adjustment. The electoromyographic activities in the anterior temporal (T) and masseter muscles (M) during tooth tapping were recorded bilaterally and the duration of the silent period (SP) before and after treatment was evaluated.
The results obtained were as follows:
1. Occurance of SP was 100% in the control group, in the TMJ group; 98%(session I),99% in during relief of pain on the region of TMJ and limitation of mandibular movement (session II), and 100% when radical care was finished (session III) and no significant differences were found between the control group and each of the sessions.
2. In regard to SP duration in the control group, no significant differences were found between the left and right in the T and M, and between T and M in the same side muscle.
3. In regard to SP duration in the TMJ group, in session I it was significantly shorter than in the control group and equal to session II. In session III significantly more prolonged than session I and equl to control group.
4. In regard to SP duration in the TMJ group, no significant differences were found between left and right in the T and M, and between T and M in the same side muscle in session I and II. However in session III, significant differences were found between T and M in the same side muscle.
5. Comparing the SP duration in the TMJ group before and after treatment, before treatment it was shorter than allowable within the limits of good health and after treatment recovered, and was within the limits of good health.

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Dentures for children (removable space maintatiners) have been defined as one method of denture guidance and used clinically as a functional space maintainer. However there are many problems which have not been solved conserning dentures for children, especially with respect to the recovery of the masticatory ability when wearing one, the authors examined the recovery of the masticatory ability. The subjects consisted of 17 children with and without dentures. They were devided into groups from IIA to IIC according to Hellman's dental age (IIA: 6 children and IIC: 11 children).
An intergrator was used to handle the EMG data and as a result of the study the following conclusions were reached.
1. In IIA the value when wearing dentures decreased than when not wearing them, but in IIC was equal, by the total action potential of the anterior temporal muscle (TA), the posterior temporal muscle (TP), and the masseter muscle (M).
2. The TA%, TP% and M% which are the percentages of the total action potential of TA, TP and M were caliculated to determine the quantity of the action between each average. Then muscular action pattern with dentures was similar to that without the dentures.
3. The percentages of the total action potential with dentures and of the total action potential without dentures were caliculated to determine relatively the quantity of individual action. Then in IIA, decreased more than in cases without dentures, but in IIC, increased.
4. The authors believe that the recovery of the masticatory ability when wearing dentures was influenced by the stability of the denture. However the masticatory ability was recovered noticeably by the occlusal condition of the first molar.

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The purpose of our study was to establish methods of conducting dental health surveys on 1Y6M old children, to find systemic oral diseases and to prevent dental caries. The subjects were children,1Y6M to 3Y6M old at 9 localities in Japan (Iwamizawa, Morioka, Sendai, Tokyo, Yokosuka, Ibaragi, Tokushima, Hiroshima, Fukuoka), and who were examined every 6 months. Also questionnaires given to their mothers were investigated.
In this report, the relationship between the environmental factors of children in the prenatal and postnatal periods (mother's age, order of birth of the children, the course of the pregnancy, trouble at birth, season at birth, the period of pregnancy, body weight at birth and the form of feeding) and the rate of eruption of the de- ciduous cuspids and the 2nd deciduous molars and the types of eruption were examined.
The results were as follows.
1. Mother's age The rate of the eruption of the deciduous teeth of children showed a higher rate the older the mothers were.
2. Order of the birth of the children (1 st born,2 nd born etc. ) The rate of the eruption of the deciduous teeth of children showed a higher rate as the order of birth increased.
3. Course of pregnancy This factor showed no significant relationship to the eruption of the deciduous teeth.
4. Trouble at birth The rate of the eruption of the deciduous teeth of children whose mothers had no trouble at birth showed a somewhat higher rate than of those whose mothers had trouble.
5. Season at birth The rate of the eruption of the deciduous cuspids of children who were born in winter showed a lower rate than of the others at 1Y6M of age, and the rate of the eruption of the 2 nd deciduous molars of children who were born in autumn showed a higher rate than of the others at 2YOM and 2Y6M of age.
6. Period of pregnancy At 1Y6M,2YOM and 2Y6M of age, the rate of the eruption of the deciduous teeth of children showed a higher rate as their mothers had longer periods of pregnancy.
7. Body weight at birth At 1Y6M,2Y0M and 2Y6M of age, the rate of the eruption of the deciduous teeth of children showed a higher rate the heavier they weighed at birth, but the rate of the eruption of the deciduous teeth, except of the upper 2 nd deciduous molars, of children who weighed more than 4501 g at birth showed a lower rate than that of the others.
8. Feeding form The rate of the eruption of the deciduous cuspids of children who were breastfed showed a somewhat lower rate than that of the others at 1Y6M of age, and the rate of the eruption of 2 nd deciduous molar of children who were bottlefed showed a higher rate than that of the others at 2YOM and 2Y6M of age.

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The subjects were a total of 40 subjects (students of Hiroshima university school of dentistry), of which 20 were males and 20 were females.
Changes in internal behavior were observed when the subjects were stimulated by dental pain which consisted of slow and sudden electric stimulus to the pulp and physical stimulus to the skin or oral mucous membrane.
The change ratios between the rest and the stimulated situations were analyzed with respect to the electrocardiogram (ECG), the respiration curve (RC), the plethysmogram (PL) and the electrooculogram (EOG).
The change ratios of resistance in stimulus were analyzed with respect to the galvanic skin refrex (GSR).
The internal changes to the dentaly painful stimuli were compared with the stimulus difference, index difference and sex difference.
1) There was no significant difference between each stimulus on the ECG, PL and EOG. However, the electric stimuli showed larger change ratios than the physical stimuli on the RC and GSR. The sudden electric stimuli showed larger change ratios than the slow electric stimuli on the GSR.
2) The total ratios of change in the index for the 7 types of stimulus decreased in the order, index-wise, EOG (152.65%) >PL (41.68%) >RC (33.64%)>GSR (12.85%) >ECG (6.53%). However, after the total ratios were standardized, there was no significant difference on each index. The variable coefficient increased in the following order, PL (0.50) <GSR (0.80) <ECG (0.84)<RC (0.88) <EOG (1.19).
3) Comparing sex groups, there was some significant difference on the RC and GSR, but there was no significant difference on the ECG, PL and EOG.

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The crestal pit is a small pit on a cuspal portion of the human tooth enamel first reported by Tokoro in 1937.
Thereafter there have been few reports on crestal pits published. Forty nine cases of crestal pits on young human permanent teeth were observed through a scanning electron microscope in this study.
Ten cases of human permanent molars were observed through a dissecting microscope, then washed in a supersonic washer, dried, gold plated using an ionspatter. The crestal pits of the cuspal portion of the teeth were observed through a scanning electron microscope and measured.
Some of the specimens were cut sagittally at the middle portion of the crestal pit, then a side wall of the crestal pit was observed using a scanning electron microscope. A maximum of 9 crestal pits per tooth, a minimum of 2 and average of 4.9 were observed. The opening form of the crestal pit was classified into four types; round 46.9%, oval 36.1%, triangle 10.2% and others 6.1%. The diameter of the crestal pit was 0.68mm maximum,0.014mm minium and average 0.173 mm.
The crestal pit is a round tube opening in a trumpet bell form in an enamel surface of cuspal portion, ended in a test tube form near the dentino-enamel junktion. In the side wall of the crestal pit, small branches were also seen in some specimens.

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This study was attempted to investigate the effect of acid-etching on primary ground enamel.
Twenty-six extracted or exfoliated caries-free primary anterior teeth were used.
The morphology of the etched enamel surfaces cleaned by water spray alone and polished dry with a dental polishing brush for 1 minute (control groups), and ground in the various depths (ground groups) were observed through a scanning electron microscope.
The outer, middle and inner enamel layers were prepared dry with the diamond bars and the carborundum points in the ground groups. The enamel layers and surfaces were then etched for 1 minute with 40% phospholic acid etchant and rinsed with water for 30 seconds.
The following observations were obtained.
I. Control groups
1. Any prism structure were not observed in some of etched enamel surfaces polished dry with a dental polishing brush.
2. Peripheral etch patterns and poorly or less structured etch patterns were observed in all cases which showed the prism structure after etching.
II. Ground groups
1. Prism structures were observed in all etched enamel surfaces.
2. No relationship between the etch patterns and the ground instruments was noticed.
3. Peripheral etch patterns (94.1 %) and poorly structured etch patterns (82.4%)were the most common.
4. Stronger dissolution occurred in the middle and inner enamel layers than the outer enamel layer. This might depend on the difference of the enamel calcification and the prism structures between the layers.

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The purpose of this study was to investigate the possible psychic trauma caused by applying the restrainer to children during dental treatment, and to elucidate the relationship between the psychic trauma and the adaptability to the clinical circumstances of the children and their mothers. Whether application of the restrainer should be encouraged or not is discussed according to the results obtained.
The complete failure of the attempt at persuasion, the tell-show-do, and the hand-over-mouth exercises to the children who resisted the treatment, finally led to the introduction of the restrainer.
Before and after treatment,43 child patients aged 3 to 5 years and their mothers were assessed with the color pyramid personality test (CPT), which is an objective test using a projective technique. According to the checklist and rating method of Kurosu, K. et al. (1979), moment-by-moment responses of the children to treatment were checked according to the list of disruptive behaviors and were rated according to four point scales; 4, cooperative like an adult; 3, tensive, but no movement; 2, little movement of the limbs; 1, violent movement of the trunk, head and limbs.
Mothers were requested to sit and watch their children during the treatment. Significant positive correlation effecients between the first and second scores of the CPT seem to indicate that the psychological tests were so properly practiced that the results are very reliable.
Results obtained were as follows.
(1) The relevant dimension of the personality to the adaptation of the children to dental treatment was related to the width of the psychological life span expressed by the items of the sequence formula in the CPT. Other items in the CPT, such as the creative and synthesis ability, and the extratensiveintroversive type of personality were irrelevant.
(2) The children who achieved a good score with the constant sum in the sequence formula of the CPT, showed a high mental ability to accept external matters through less selective judgements and the cooperative and tranquil behavior during treatment. There was, however, no significant correlation between mothers' personality attitude and their children's behavior.
(3) The application of the restrainer increased the non-selective acceptability of the children, and the ability of the mothers to accept external stimuli with proper selectivity, which is a feature of the maturation of personality in adults. From these results, the application of the restrainer effected no psychic trauma on the children nor on their mothers, and the application should be more or less encouraged. However, it must be taken into account that the application of the restrainer in the present investigation was only resorted to as a last mean after the failure of all other exercises, such as the tell-show-do, the persuasion and the hand-over-mouth.

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Hemihypertrophy is characterized by overgrowth of one half side of the body with or without unilateral hypertrophy of the face. In hemihypertrophy of the face, both skeletal and soft tissues are usually involved. The causes is unknown. The dental findings are premature eruption and development of the teeth, macrodontia, and malocclusion. There is a tendency to have some congenital missing teeth.
This report is a serial observation of a case of hemihypertrophy which was observed for 6 years from the age of 3 to 9.
The results were as follows;
1. The tongue was enlarged and thickend on the left side of the face, and the fungiform papillae were grossly hypertrophic.
2. The facial appearance was asymmetrical. The soft and hard tissues, such as the lips, palate, maxilla and mandible, were also enlarged on the affected side.
3. Because of decayed deciduous teeth, it was very difficult to decide whether side were larger than those on the normal side, or not.
4. There were no differences in the mesiodistal and buccolingual diameter of the permanent dentition.
5. There was a fusion of the erupted primary teeth in the lower jaw.
6. The shape and size of both the deciduous and permanent teeth as well as the number were normal which revealed no differences between the right and left sides.
7. This case had not shown any familial history.
8. The carpal bone, which was underdeveloped at the age of 3, was almost normal at the age of 9.
9. Over the 6 year period, the left side of the tooth germ grew rapidly compared with the right side.
10. There was shown severe malocculusion of the permanent dentition.

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An 11-year-old female came to the pedodontic clinic of Tsurumi University Dental Hospital with a chief complaint of carious lesions. She did not have any systemic disorders. Full-mouth radiographic examinations including orthopantomography and occlusal film survey, revealed an abnormal eruption process of the bilateral upper canines causing root resorption of the bilateral central and lateral incisors. In addition to these findings, X-ray cephalometric analysis showed a skeletal Class III malocclusion pattern, indicating that these incisor root resorptions were also associated with a discrepancy between the tooth material and the basal arch length.
Dental treatment commenced with treatment of the carious lesions, because of the psychological considerations given to this particular case. Extraction of the upper central incisors was then performed when the upper canines were expected to erupt soon. After the eruption of both canines into the position of the central incisors extracted, the multibrackets appliance was utilized for correction of teeth alignment.
Finally, the jacket crowns having the shape of the central incisor were cemented on the canines correctly repositioned.
The patient is 17 year 10 months of age at present time.
The comprehensive treatment rendered has brought about a satisfactory result either functionally or esthetically.

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Grass fiber and orthomite super-bond were employed for the stabilization of traumatized deciduous teeth as a treatment. The procedure was described and two classical cases with this treatment were presented. This procedure is a very useful and convenient approach for the treatment of traumatized primary teeth among young children.
The advantages of this method are as follows;
1) The method, using a fiber-glass splint, requires no laboratory work.
2) This method will minimize the time assumed for treatment.
3) Very few equipment is necessary for this splinting technique, which is easily applied even in the case of younger children.
4) The stability of the fiber-glass splint is much more secure than that of the resin splint.
5) An application of this splint causes little disturbance in the oral function.
6) The splint can be swiftly removed and has negligible effect on the enamel surfaces.
7) This method was revealed to keep the normal occlusion and articulation, which will also be aesthetically accepted.

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A tooth is described as submerged if it has erupted normally and reached the occlussal plane, but due to some cause or other, fails to maintain its position and at last locates below the normal occlusal plane.
An 11 years 9 month old girl was refered to the Pedodontics Clinic of Hirosima University School of Dentistory with the chief complaint being esthetic dissatisfaction with the maxillary anterior portion.
Oral examination revealed that the bilateral maxillary first deciduous molars were submerged teeth. The principal observations are as follows.
1) Most of the crown was located below the gingival margin, so that inspected from the buccal side only the buccal cusp was recognized.
2) Except for the cusps and part of the occlusal surface, the crown was covered with the gingiva.
3) The occlusal surfaces were restored with amalgam filling material. But because of insufficient plaque control, secondary caries were found at the marginal region.
4) Roentogenographical examination revealed the absence of many succeeding permanent teeth involving the bilateral maxillaly first premolars.
The roots of the submerged teeth were exceedingly resorbed, so only part of the palatal root was observed. Periodontal membrane space and lamina dura were found on only the mesial side of the roots.
The right one showed radiolucency resembling a proximal carious lesion on the distal surface of the crown.
We decided to extract both of them because of the lack of any occlusal function, the susceptibility to dental caries and periodontal disease, and the inducement of malocculusion.

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A 7 year and 4 month old boy was referred to the Pedodontic Clinic of Hiroshima University School of Dentistry with a chief complaint of abnormally shaped teeth (21).
He was born of a normal pregnancy and delivery.
Consultation with a pediatrician revealed that his development was normal and very healthy at the time.
The principal observations are as follows:
1) A fused mandibular right central incisor and lateral incisor was found and as well as crowding of that region.
2) Based on the radiographic findings, the apices of the mandibular right central and lateral incisor fused teeth were discovered to be not completely formed.
3) The crowns of the fused teeth were divided with a diamond bar because the roots were separate.

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We experienced a rare case of inverted impaction of the maxillary left deciduous central incisor.
This patient had visited our clinic because his parents were anxious about the delayed eruption of his maxillary left deciduous central incisor. He was five years old at that time. In this case, no difinite history could be obtained as to whether this tooth had failed to erupt.
In the oral examination, there is no anomaly except for the absence of the maxillary left deciduous central incisor and the non unified median line of upper and lower teeth was found.
In the X-ray examination, we recognized an inverted maxillary left deciduous central incisor. There were no supernumerary teeth, odontoma or tumors. During the observation, we found exposure of the root surface at the labial cervical region.
After 1 year and 2 months, we extracted the impacted tooth and we observed it histopathologicaly by microscope.
1) The impacted deciduous tooth had a strong resemblance to his erupted maxillary right deciduous central incisor.
2) Resorption occurred at the root of impacted tooth and a small amount of cementlike hard tissue was found there.
3) We found much secondary dentin on the wall of pulp cavity in the labial cervical region. This part was exposed on the gingiva during the observation.

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