A nation-wide field survey was undertaken to examine clinical causes for hypoplasia of primary teeth in 141 children above 3 years of age with primary dentition having enamel hypoplasia. The survey was carried out by visual examination, photographic evaluation and questionnaire survey. The controls consisted of 120children without enamel hypoplasia.
The following results were obtained.
1. Hypoplastic teeth due to inflammation, trauma or radiation were not found.
2. Based on the configuration of the hypoplastic teeth, the place of birth and type of nursing, the teeth that developed enamel opacity could not necessarily be regarded as to mottled teeth.
3. No correlation was found between the unbalanced diet of the mothers during pregnancy and the occurrence of the hypoplastic teeth.
4. The development of enamel hypoplasia was estimated to have occurred from the neonatal to infantile stage for the primary canines and from the fetal stage to the early stage of birth or 6 months after birth for second primary molars.
5. Hypoplasia seemed to have begun from the stage of the matrix formation in many cases.
6. Among the mothers during embryogenesis, threatened abortion, severe hyperemesis gravidarum, anemia and drugs used in the treatment of these symptoms seemed to be responsible for the development of hypoplasia. Among the children, diseases occurring within one year after birth, exathematous diseases such as exanthema submonia, common cold and pneumonia, Jaundice, intussusception and asthma seemed to be responsible.
7. The number of enamel-hypoplastic teeth per child increased, as the frequency of diseases in both mothers and children increased.
8. The kind of teeth susceptible to damage, the time of damage, the sensitivity of individuals, and the kind and severity of damage seemed to interact in the etiology of hypoplasia.

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A nation-wide field survey was carried out to investigate the etiology of enamel hypoplasia for permanent teeth in 286 subjects below 20 years of age with permanent dentition having enamel hypoplasia. Visual examination, photographic evaluation and questionnaire survey were used. The same questionnaire survey was also carried out in 111 subjects without hypoplastic teeth as controls.
The following results were obtained.
1. The number of hypoplastic teeth ranged from 1 to 28 per subjects.
2. Upper central incisors were frequently involved, especially in subjects with few permanent teeth. Enamel hypoplasia in these teeth appeared symmetrically.
3. Only a few hypoplastic teeth seemed due to local causes. Hypoplastic teeth were not considered to be mottled teeth caused by fluoride.
4. Unbalanced diet (food liked and disliked) during pregnancy was not related to dental hypoplasia.
5. In subjects with many colored teeth, maternal diseases during embryogenesis and drugs administered for treatment were considered tobe etiologically involved in the development of hypoplasia.
6. Viral infection during childhood seemed to be involved in the development of hypoplasia.
7. Many of the subjects with more than 7 hypoplastic teeth or colored teeth had contracted diseases during childhood. Moreover, the development of both viral infection and other disease was frequent.
8. The kind of teeth liable to damage, time of damage, sensitivity of individual subjects, multiple stimulation.

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α-Tocopherol contained in human blood cells was oxidized by a photosensitized reaction in the presence of hematoporphyrin as a photosensitizer. Participation of singlet molecular oxygen, superoxide radical and hydrogen peroxide in the photooxidation was not so significant, although hematoporphyrin can generate singlet molecular oxygen on illumination. Quercetin inhibited the photooxidation of α-tocopherol. Both in the prescnce and in the absence of linoleicacid, photooxidation of α-tocopherol which was suspended in the PBS solution was also inhibited by quercetin. The rate of the photooxidation of α-tocopherol in the presence of linoleic acid was faster than that in the absence of the fatty acid. When quercetininhibited thc photooxidation of α-tocopherol contained in blood cells or suspended in PBS solution, quercetin was oxidized. The photooxidation of quercetin, which was suspended in the PBS solution, was inhibited by α-tocopherol in the absence of linoleic acid, but stimulated in the presence of the fatty acid.

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The purpose of the present study was to investigate the image on the dental environment of the mothers of handicapped and normal children. To investigate the image on dental environment, the Semantic Differential Methcd was applied to mothers of 42 handicapped and 35 normal children. They rated 4 items -‘dentist’, ‘my child’, ‘dental treatment’ and ‘dental operating room’ -on the adjective-scales 12 pairs.
The results of this study ware summerized as follows:
1. In comparing the mean of the rating score, it observed that the mothers of handicapped children have a more positive image than the mothers of normal children. This tendency was appeared more clearly at ‘dental treatment’ and ‘dental opeating room’.
2. By principal factor analysis and varimax rotation,2 factors were extracted from every 4 items.
3. Factor scores at factor 1 and factor 2 of the mothers of handicapped children were different from those of the mothers of normal children. The mothers of handicapped children had views that a dental treatment is ease and acceptable, and that a dental operating room is comfortable and safe.

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This study was undertaken to examine the effect of a hot water extract from Japanese tea on the cellular growth of mutans streptococci in vitro.
The extract contained polyphenol compounds, mainly catechin derivatives. Few fluoride components were contained in the extract. Streptococcus mutans MT8148R (serotype c) and S. sobrinus MT6715 (serotype g) strains were used in the present study. The organisms (10-10⁷ CFU/ml) were cultured in brain heart infusion (BHI) and tryptose phosphate (TP) broths containing the tea extract (0-8mg/ml). After incubation for 24-48 hs, the cell numbers in the cultures were determined. Furthermore, cell growth of these strains on BHI agar plates containing the extract (0-2 mg/ml) were examined.
The results obtained were as follows:
1. The tea extract (2-8 mg/ml) in BHI broth inhibited remarkably the growth of S. mutans and S. sobrinus (incoulum size; 10⁶ CFU/ml). No difference in susceptibility to the tea extract between S. mutans and S. sobrinus was noted.
2. The cell growth of both strains in TP broth was inhibited by the tea extract. However S. sobrinus was found to be more sensitive to the extract than S. mutans.
3. Growth of S. sobrinus cells on the BHI agar plate was suppressed by the tea extract more effectively than that of S. mutans.
These results suggest that the tea extract would be useful as an anti-cariogenic agent.

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The purpose of this study was to investigate a treatment system indtened to promote improvement in the cooperation of patients. Thesubjects of the investigation were 45 uncooperative patients who had difficultyin accepting regular dental treatment.
This treatment system consists of A) caries inhibition stage by Ag(NH₃)₂F, B) first temporary restoration stage with low viscosity glass ionomer cement, C)second temporary restoration stage with restorative glass ionomer cement and D)final restoration with regular restorative material.
One treatment stage in the system was carried out according to the grade of the cooperation of the patients, then the advanced treatment stage superseded the former when the cooperation was improved.
The period of time required for the improvement of cooperation, and the durability of the glass ionomer cements were examined.
The following results were obtained.
1. The durability of the low viscosity glass ionomer cement was 11 months for the anterior teeth, and 12 months for the posterior teeth.
2. The durability of the regular glass ionomer cement was revealed to be 18 months for the anterior teeth and 17 months for the posterior teeth.
3.7 months were required for the improvement in the cooperation of the patients from stage B to stage C and 14 months for improvement from stage C to stage D.
4. Improvement in cooperation appeared in a shorter time when this treatment system is begun to be applied to the patients at lower age. The staged restoration system is an effective method for the behavior management of uncooperative patients. The glass ionomer cements are useful for the temporary restorative material, since the period of durability is longer than the time required for the improvement of cooperation.

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Object of investigation
The retention of composite resin to etched stainless steel crowns was tested as a possible method for restoring primary anterior teeth. Method employed
1) SEM observation Stainless steel crowns (Sankin Manufacture Co. ) were etched with an aqua resia to create surface roughness and undercut to retain the composite resin to the crowns. Etching times were 1,2,3,5,8,10 and 20 minutes, then washed in a 70% alcohol solution using an ultrasonic washer and dried. A total of 96etched samples and non etched control samples were observed through the scanning electron microscope (Hitachi 520).
2) Shear bond strength test Stainless steel crowns were etched in an aqua resia from 1 to 20 minutes, then washed and dried. Composite resin (Photo Clearfil A, Kuraray Co. ) with the bonding agent was placed on the crowns and the shear bond strength was tested in 56 samples using an Autograph (DCS-500, Shimazu).
Results
1) SEM observation showed that the etching surface of stainless steel crowns created surface roughness and undercut. The most desirable surface was obtained in the 3 to 5 minute etching time specimens.
2) The highest bond strength was obtained in a 3 minute etching specimen. It was 42.12 MPa, although 29.26 MPa in mean value.
Conclusion
Etching with an aqua resia increased the adherence of composite resin to the surface of stainless steel crowns.

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The purpose of this study was to investigate the color changes of light-cured composite resins over specified periods of time.
Composite resin disks which were 10 mm in diameter and 1 mm in thickness, and made by the 3M Co. light-cured composite resin Silux Plus (shades: U, Y, DY, L, G, UO, YO) were made with 2 minutes of light exposure through a 1 mm thick glass plate. The spccimens were stored in 37°Cartical saliva.
Chromatical values of the specimens immediately after curing,1 day,1 month,3 months,6 months and 1 year after curing were measured without background color, backed by a white plate.
Color measuring was performed with the Murakami Color Research Laboratory Fast Spectrophotometer CMS-500 and the Flexible Sensor FS-3.
1) In the cases without background color, the ΔE*ab values of all shades increased for 1 year proportionately to the time elapsed. In the cases backed by a white plate, the ΔE*ab values of all shades increased for 6 months after curing, however, compared to the 6 month ΔE*ab values, the 1 year ΔE*ab values increased in some shades and decreased in other shades.
2) Both in the cases of with and without background color, compared to the ΔE*ab values of immediately after curing, the 3 month ΔE*ab valucs of all shades were over 1.2, and the 1 year ΔE*ab values of many shades were near or over 2.5and detectable to the naked eye.
3) Both in the cases of with and without background ccicr, the L* values of all shades decreased for 6 months after curing. However, compared to the 6 month L* values, the 1 year L* values decreased in some shades and increased in other shades.
4) In the cases without background color, the a* values of all shades increased for 1 year after curing. In the cases backed by a white plate, the a* values of all shades increased for 6 months, however, compared to the 6 month a* values, the 1 year a* values of all shades decreased.
5) Both in the cases of with and without background color, compared to the b*values immediately after curing, the 1 day b* values of all shades increased, then the b* values of all shades decreased between 1 day and 1 month after curing, and the b* values of many shades increased between 1 month and 6month, however, compared to the 6 month b* values, the 1 year b* values increased in some shades and decreased in other shades.

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Previously we investigated the frequency of malocclusion in children who visited the Pedodontic Clinic of Kyushu University and the types of appliances to treat the reversed occlusion in deciduous dentition. The purpose of this study was to evaluate the effects of the maxillary protracting bow applicane to the reversed occlusion in deciduous dentition.
Patients at the Hellman's dental age IIA and without molar cross-bite were selected. Eleven patients (6 males and 5 females) were treated with the maxillary protracting bow appliance, and 9 patients (5 males and 4 females) were treated with the chin cap. The controls were 15 patients (5 males and 10 females) without, distal step type of terminal plane, caries and malocclusion.
For the sake of evaluation, the study models and lateral cephlograms were analyzed, which were taken before and after the correction of reversed occlusion.
The results were as follows:
1. The effects of maxillary protracting bow appliance were the maxillary forward movement associated with counter-clockwise rotation of the nasal floor and the mandibular backward movement associated with clockwise rotation.
2. The maxillary prtracting caused the labial inclination of the primary incisors in the maxilla, but the dental arch length was reduced by the mesial movement of the primary second molars in the maxilla.
3. From the results of multiple regression analysis in the maxillary protracting group, it was indicated that the increase of the overjet was attributable to the change of angles of SN-GN, SNB, SNA and GZN.

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A lateral cephalogram analysis system has been developed allowing an extended application of the Ricketts analysis to primary dentition. Using this system, we first examined the growth of facial patterns from the BA-NA ratio profilograms. As samples, we used records of children with normal occlusions stored at Nihon University School of Dentistry Department of Pedodontics. We then used the Fuzzy theory to change Vert's formula and obtained facial types. Lastly, we obtained compositional ratios of facial types within each age group. The results were as follows:
1) Facial patterns tended to show three divisions according to three age groups; from 3 to 5-year olds, from 6 to 7-year olds and from 8 to 10-year olds.
2) The Vert's values of the BA-NA ratio profilograms in each age group based on the data of 9-year olds tended to decrease as age increased. The change was mostly restricted to the range of Mesiofacial type.
3) As for the compositional ratio of facial types in each age group, a nearly normal distribution was observed mainly with the Mesiofacial type.
4) From the lateral cephalogram analysis system which has been developed and the profilograms of the average values for each age group which have been obtained by this system, we obtained the standard values for future evaluation of facial patterns of children with malocclusions.

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Drooling is a significant problem demonstrated by individuals of all ages with a variety of etilogies such as neurological disorders, cerebral palsy, mental retardation and others.
Persistent drooling not only creates troublesome hygienic problems for patients, teachers, nurses, and playmates because of the constant soiling of clothes, toys, and work materials, but also causes an odor from their clothing and bibs.
The older patient with normal cognition is disturbed by the drooling and may become depressed and reclusive.
Successful management of drooling alleviates these problem, improves appearance and self-esteem and significantly reduces the time involved in the care of the sufferers.
The author, who had studied at the University of Toronto for 2 years, acquired the technique of submandibular duct relocation under the guidance of Dr. Crysdale.
We carried out the surgical procedure of submandibular duct relocation for drooling on six patients who had cerebral palsy.
The surgical procedure resulted in a drmatic decrease in drooling and odor levels.
All of them improved in appearance, and the time involved in the care of the suffers was significantly reduced.
The complication of ranula, however, appeared in two cases, which suggested a much higher frequency than that in the report of Crysdale.
It seems that a detailed explanation to parents and teachers about the advantages and disadvantages of submandibular duct relocation is important.

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The purpose of this study was to investigate the methods involved in observing the muscle fiber conduction velocity (MFCV) both in the masseter muscle and the m. biceps brachii in healthy persons.
Three adults were the subjects in this study, none of whom had any gnathofacial dysfunction. The EMG activities were recorded from the m. biceps brachii with the arm bent at right angles and the masseter muscle in the intercuspal position, in both muscles during 50% of maximum voluntary isometric contraction on the habitual side. Three types of surface electrodes were used; Type 1. the disc type electrodes array arranged straight, Type 2. the disc type electrodes array arranged independently, Type 3. the strip type surface electrodes array arranged straight. The EMG activities preamplified at three conditions of time constant, e. g.,0.003,0.01,0.03 sec on m. biceps brachii were analyzed through a personal computer system and a FFT analyser. The conduction velocity was calculated by the cross-correlation method.
The results obtained in this study were as follows:
1) No differences in the MFCV between the time constant were noticed.
2) The electrode array arranged straight was effective in the measurement of the MFCV in adults and in particular the strip type series electrodes array arranged straight was the most effective to measure the MFCV in the masseter muscle.
3) The average MFCV of the m. biceps brachii and the masseter muscle were 4.13±0.29m/sec and 14.28±1.21 m/sec respectively.

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The purpose of this study was to evaluate the Fast Fourie Transform (FFT)analysis of the occlusal sounds generated by tooth tapping which may apply in assisting in the functional diagnosis of occlusion in children. The fifteen subjects examined were devided into three groups: the first group with deciduous dentition, the second with mixed dentition and the third with permanent dentition. Occlusal sounds generated by tooth tapping at the rate of 76 times per minute were obtained with a micro-electronic condencer microphone placed on the infra-orbital region. For the time wave, the wave pattern of the occlusal sound was classified into two groups:1) Impact sound,2) Slide sound, and the ratio of appearance was examined. For the spectrum, three parameters were chosen for the measuring points such as 1) frequency range,2) peak frequency,3) strength of the peak frequency. The results obtained in the present study were summarized as follows:
1) Occlusal sounds in the deciduous dentition, the appearance of sliding sound was noticed in over 50% of the cases while on the permanent dentition, the sliding sound was dominant.
2) The power spectrum of the occlusal sound showed generally two or three peaks.
3) The range of frequency was recognized to be extended on the sliding sound when compared with the impact sound.

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A stastical study was carried out to evaluate the circumstances of the oral habits of the children aged 3-15 yr. (423 boys and 379 girls,802 children in total) in a mountain village through psychological tests and investigation of the living environments of children and their parents. The following results were obtained:
1. The peak age of finger sucking was 3 years with girls (35.7%) and 4 years with boys (22.2%). After these ages a tendency to decrease in frequency was observed.
2. The peak age of the nail biting was 11 years in girls (26.5 %) and 10 years in boys (18.8%). However, the nail biting was observed in girls from infancy.
3. The peak age of bruxism was 7 years in boys (22.7%) and 4 years in girls (15.4%).
4. Based on sex, nail biting was found more with girls than with boys, on the other hand, bruxism was found more in boys than in girls. There was no difference in finger sucking.
5. Based on the analysis of the relationship between oral habits and personality characteristics, nail biting and bruxism showed a tendency twoards a low percentile in almost all of the items of personality characteristics, however, scarely any relationship was found in finger sucking.
6. Based on the analysis of quantification type III, the development of each oral habit showed a relationship to different personality characteristics.
7. In relation to the living environments, the nail biting occurred more in children whose mothers did not work than with those whose mothers worked, and bruxism occurred in the children who often play outdoors.

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The purpose of this study was to investigate the changes of vibration frequency of a deciduous tooth due to physiological root resorption. The author developed an analysis system for tooth vibration by applying an impact-hammer to the tooth. Peak frequency (Hz) of the tooth stimulated by the impact-hammer was observed by the analysis system.
The following results were obtained;
1) Peak frequency of the tooth vibration shifted to a lower range according to the root resorption both in vitro (simulation model) and in vivo (15 children) and a high positive correlation was found between the peak frequency and the crownroot length ratio (r =0.840).
2) A cause of the frequency shift to the lower range was not related to the tooth weight but to the change of tooth gravity due to the root resorption.
3) It was considered that the vibration analysis system could be useful on measuring tooth movility in vivo and in clinic as well.

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Osteogenesis imperfecta (OGI) is a rare genetic disease which, as a result of a disorder in the formation of the organic stroma of the bone due to a defect in osteogenic function, induces brittle bones, whereby only weak forces bring about multiple, repeated pathological fractures.
This disease is thought to entail various problems with regards to carrying out pediatric dentistry due to the ease with which bones may be fractured.
We report here the findings obtained as a result of the careful examination of a 1-year-3-month-old girl encountered in our practice and who was diagnosed as having osteogenesis imperfecta.
1) Out of the three major symptoms for osteogenesis imperfecta, this case showed signs of fragile bones and blue scleras, but did not reveal signs of deafness.
2) There was retardation in system growth and development.
3) Aside from a high level of alkaline phosphatase, there were no notable abnormalities revealed in the biochemical blood tests.
4) Dentinogenesis imperfecta was observed throughout the erupted teeth.
5) There was a definite improvement in cooperation with each visit to the clinic.

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Although composite resin has been used as an aesthetic restorative material, wear and fracture of the resin of fracture of the tooth structure are likely to occur when the size of the dental cavities are large. In addition to the lack of the aesthetic value, clinical results of prefabricated metal crown revealed several problems which were caused by the wear of the metal and the ill-adaptation of the cervical margin.
In the present study,50 devitalized deciduous molars were treated with composite resin onlays which were designed to cover the entire occlusal surface of the deciduous molar, and the clinical results were evaluated for a 6 month period.
Additionally, for the purpose of simplification of the laboratory process for making resin onlays, ready-made occlusal shells were fabricated. The varaiety of the prepared shell size consisted of 7 sizes for the first deciduous molar,9 sizes for the upper second deciduous molar and 10 sizes for the lower deciduous molar.
The following results were obtained.
1) A partial resin fracture at the peripheral area of the mesio-buccal cuspid was found in five cases out of 50.
2) A glossy appearance on the surface of the onlay which was created by coated unfilled resin disappeared after 6 months of observation.
3) In relation to the resin onlay, when the antagonistic tooth was restored with prefabricated metal crowns, holes were made by attrition on all the crowns within a 3-4 month period.
4) Resin onlays which were designed to cover the entire occulusal surface of a tooth are preferable for the restoration of devitalized deciduous molars because this type of restoration requires a large removal amount of the tooth structure.
5) When prefabricated occulusal shells were used in the laboratory procedure for resin onlay, there was a considerable reduction in working time. As the results show, the resin onlay is an effective restorative method in an alternative to the metal crown or the resin filling for the restoration of devitalized deciduous molars.

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In March 1987, we investigated the quality of oral hygiene, and the incidence of dental caries and periodontal diseases in 140 severely handicapped patients who had been hospitalized in two national sanatorium. All of the patients had participated under the Matsumoto Dental College Hospital Periodic Dental Check-up System for five years.
The results were as follows;
1. The teeth of all the subjects had been brushed by the sanatorium nursing staff twice per day. The prevailing brushing technique was the horizontal method.
2.37.5% of the subjects showed complete adaptability to the tooth brushing by the nursing staff. However,2.1% showed no adaptability whatsoever.
3. The mean value of the OHI-S was 1.53. The labial surfaces of the maxillary anterior teeth showed the lowest OHI-S value, while the mandibular left posterior teeth showed the highest.
4. The DMF-T was estimated to be 12.51 (DMFT ratio=48.2%). The average D-T was 2.07±4.03, and the average F-T was 8.43±7.22.
5.19.3% of the patients were diagnosed with gingival hyperplasia, and 10.7%had local gingival recessions.
1) Of the patients who had taken Phenytoin daily,35.5 % were diagnosed with hyperplasia.
2) Most local gingival recessions were found on the labial gingiva of the mandibular anterior teeth. A relationship was determined to exist the local recession and the horizontal brushing method.
6.89.2% of the patients suffered from periodontal diseases. On examination using the Community Periodontal Index of Treatment Needs (CPITN), we found that 30.0% of the subjects showed bleeding by probing only (code 1),32.3% had supra or sub-gingival calculus (code 2),23.1% had shallow pockets of 4 to 5 mm (code 3), and 3.9% had deep pockets of more than 6 mm (code 4).

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Sialolithiasis occurs due to the calculous concretion in salivary ducts or glands, but it is rare in childhood.
In this paper, a case of sialolithiasis with a submandibular duct calculus observed in a 2-year-old girl is reported. This case is one of the youngest, based on a review of the literature regarding sialolithiasis found in Japan.
The retrospective survey was made in 30 cases of sialolithiasis in children under 10 years of age which were reported in the Japanese literature with clear descriptions of age, sex and location.
The summaries are as follows:
1) Sex difference: The difference between males and females was in the ratio 16/14. There was no significant difference according to sex.
2) Location of the salivary calcul: In 27 cases they were found in the duct of the submandibular glands, and 3 cases in the parotid glands, and no cases in the sublingual glands.
3) Term before treatment: Most cases were treated within a month after the patients has noticed the symptom.
4) Removal method of salivary calculi: Salivary calculi were removed by means of intraoral incision in most cases.
5) Number of the removed calculi: In each of all cases, one calculus was removed.
6) Size of the removal calculi: The diameter of the calculi was less than 5.0milimeters long in most cases.

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Splinting was administered in a case of a traumatic upper right permanent incisor with root fracture. The patient was a boy,11 years and 10 months old. The radiographical examination indicated that the injuried tooth, that had already completed the apical growth, fractured horizontally at the middle 1/3 part of root. Clinical findings showed severe mobility of the coronal fragment of the injuried tooth and a small amount of bleeding from the gingival sulcus, but there was almost no disposition of the coronal fragment and it was found to be vital in the electric pulp test. Immobilizing the coronal fragment of the injuried tooth with the resin splint bonded directly to the tooth surfaces was prescribed.
After 31 months, the pulp of the injuried tooth remained vital, and after the elimination of the line of fracture and no symptoms of ankylosis were radiographically confirmed, the splint was then removed.
From the case reported above the following implications were obtained:
Although the previous investigators reported that the term of splinting teeth with root fractures was for 2-3 months, and prognosis of the injuried teeth with root fractures having severe mobility of the coronal segments might be unfavorable, it was also indicated that the healing process by calcification might be possible with the use of long term splinting, as the pulp remained vital.
In this case, it was found that the repair by calcification appeared initially on the proximate portion of the pulp at the fractured line, and slowly proceeded into the direction of the site of the outer surface of the root along the fractured line.

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The Hallermann-Streiff Syndrome has been characterized and established according to 7 positive and 5 negative signs, which were described by Francois. We encountered an 11 year,5 months old boy who had 7 positive symptoms of this syndrome in our clinic. In this study, we reported on this typical patient focusing on his dental view.
1) Prolonged retention of the primary teeth which involved microdontia were noted. Congenitally missing teeth were also seen.
2) The occlusal relationship indicated open bite, and also the mandibular function was impaired.
3) The measurements of the length and width of the dental arch were smaller than that of a normal subject, and the dental arch of the maxilla was V-sharped.
4) According to X-ray cephalometric analysis, (a) the dental calculus and the alveolar bone absorption were very evident. (b) abnormal morphologic of the glenoid fossa, mandibulars condyle and the neck of mandibula were seen. These condition were very evident on left side.
5) The growth obstade of the maxilla and mandibla and the left shift of the mandible were found.
6) According to histological study, enamel hypoplasia was noted.

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The purpose of this study was to evaluate the influence of minor surgery conducted in the oral cavities of children. Changes in blood pressure and pulse during minor surgery were measured using a Pulse-Wave Korotokoff Sound Record Meter GP-303S (PARAMA). The subjects consisted of 28 children (15 boys and 13 girls) who underwent minor surgery at the pediatric dental clinic of Iwate Medical University. An examination of 16 of the 28 children to determine the relationship between their physique, personality, and blood pressure was made.
The following results were obtained:
1) The maximum blood pressure formed a peak at the time of the impacted supernumerary teeth extraction. This was more conspicuous in boys than in girls. The pulse rose to the highest values with the infiltration of the anesthesia, the incision, and stripping. However, no significant values based on sex difference were demonstrated.
2) The maximum blood pressure changed more intensely during surgery in boys than in girls. This was distinctly observed during extraction of the impacted supernumerary tooth.
3) Both the maximum blood pressure and pulse increased with the progress of the surgery. After the surgery, it returned nearly to the presurgical level. With extraction of a supernumerary tooth and marsupialization, the return of the blood pressure to the preoperative level was more delayed in boys than in girls.
4) The changes in blood pressure and pulse seemed to be mostly induced by mental disquietude and stress such as anxiety and fear of surgery.
5) The physique and personality were related to the changes in blood pressure and pulse during minor surgery in the oral cavity.

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Clinico-statistical observation was performed on the dental surgery in the Pedodontic Clinc of Niigata University Dental Hospital during the period from August 1979 to September 1989.
1. The number of surgical operations amounted to 656 cases (males 384 and female 272) and the highest age incidence was in the 6-8 year old range.
2. The incidence of the impacted teeth (62.8%) and the abnormality of the frenum (22.8%) occupied over 85% of all the cases.
3. Based on sex, the impacted supernumerary teeth and the abnormality of the buccal frenum, odotoma were more frequent in males, while the abnormality of the upper frenum and the mucous cysts weie more frequent in females.
4. About 40% of the operative patients accepted were introduced from other medical institutions.
5. Regarding the methods of surgery, the impacted permanent teeth were frequent revealed by surgical exposure, while the diseases of salivary glands were revealed by extirpation. The benign tumors were removed by extirpation, the diseases of soft tissues by excision, cysts in the jaws were all surgically removed by marsupialization.
6. In regard to the age at the time of the operation, the abnormal frenum were often seen under 4 years of age but a large increases were found in the impacted teeth from 4 to 8 years of age. The diseases of salivary glands and of soft tissues were seen more frequently under 10 years of age, and cysts in the jaws were noted after 7 years of age.
7. Children undergoing surgery who suffered from general diseases amounded to 31 cases and were found the most commonly in cases of nervous menta diseases.
8. Surgery for frenectomy occupied 14 cases among the 16 cases which were given under general anesthesia and the ages of operation were in the range of 1 to 6 years of age.
9. Postoperated complications which had hemorrages 3 cases, fever 2 cases and allergy 2 cases due to the reaction of antibiotics were found.

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The problem and treatment of the ectopically erupting permanent first molars have been addressed by many authors since they were first mentioned in the literature by Chapman in 1923. Many treatments involve techniques using the primary second molar. It is better for correcting the eruption of the permanent first molar into normal occlusion to maintain the primary second molar in its normal position. However severe mobility and root resorption are often present when an ectopic eruption is found.
An 8-year-old male with ectopic eruption of the maxillary right permanent first molar was examined and treated. The right primary second molar demonstrated severe mobility and root resorption, and therefore a new appliance using the primary first molar was designed. After 4 monthsfrom the begining of the treatment the mobility of the primary second molar decreased, and after 6 months the permanent first molar almost erupted in its normal position.

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The purpose of this study was to learn about the appearances and continuous changes of epithelial pearls.
The study group comprised 517 normal newborn babies (261 males and 256females) aged from 24 hours of birth to 22 days. Furthermore, we made the followup survey on the continuous changes in 21 newborn babies at the Niigata University Medical Hospital.
The following results were obtained by analyses of the examination of the oral cavity in newborn babies during the period from December 1987 to December 1988.
1) Yellow-white in colour, pinhead shaped,1-3 mm diameter in size, elevated firm nodules were seen in the alveolar ridge mucosa of the maxilla, mandible and / or palate. The average number of epithelial pearls was 1-3.
2) The number of newborn babies who had epithelial pearls was 226 (109 males and 117 females) out of 517 (43.7%). There was no predominant sex perference.
3) The most common location was the maxillary alveolar mucosa (309,72.5%)followed by the median palatine raphe (97,22.8%) and mandibular alveolar mucosa (20,4.7%).
4) In this study, the relationship between the environmental factors of newborn babies in the prenatal and postnatal periods (mother's age, the course of the pregnancy, trouble at birth, the period of pregnancy, baby weight at birth etc. )and the rate of appearances of the epithelial pearls was examined. These factor showed no significant relationships.
5) Based on the findings of the clinical investigation of epithelial pearls during neonatal period, some cases were found and involved thickening and / or thinning in changes in the quantity and number.

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