Seventy class II composite resin restorations in primary molars were clinically evaluated at the baseline,6-month recall, and 12-month recall visits, using the modified Ryge criteria and bite-wing radiographs. The clinical procedures included cavity preparation with a round bevel on the occlusal margin, the use of hydrophilic bonding agent of P-50 (3 M) or Palfique Light Posterior (TOKUYAMA)system, and the application of glass ionomer lining cement on the gingival wall.
The results up to one year were as follows;
1) In the 12-month follow-up, there was no difference in clinical performance among the composite materials, and there was found no loss of the restoration, marginal discoloration, color change, postoperative pain, pulp irritation, and secondary caries.
2) The results for proximal adaptation, wear, and surface roughness were satisfactory.
3) Although 17 cases (9 sites) had loose contact at the baseline evaluation, all had recovered by the 6-month recall.
4) Body fracture of the composite resin was found in 3 cases in 6 months, and in a further 3 cases between the 6- and 12-month recalls, of which 4 cases were retreated.
5) Early marginal microfracture should be noted since slightly poor marginal adaptation was found in 15 cases in 6 months, and in a further 9 cases between 6 and 12 months. However, by polishing the marginal step,10 out of 15 cases at the 6-month recall were found to maintain good marginal adaptation at the 12-month recall.

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The aim of this study was to explore the effects of the insulin-like growth factor-I (IGF-I) on cell growth, alkaline phosphatase (ALPase) and protein synthesis in human periodontal ligament fibroblasts derived from deciduous teeth (HPLF-Y) compared with those of human periodontal ligament fibroblasts derived from permanent teeth (HPLF). The cellular responses of IGF-I were examined and the following results were obtained:
1) After a 12-day culture of HPLF-Y the IGF-I caused a dramatically enhanced DNA content cornpared with HPLF.
2) The incorporation of ³H-thymidine (³H-TdR) was demonstrated in the DNA of both HPLF-Y and HPLF exposed to IGF-I. During the growth phase IGF-I stimulated the incorporation of 3H-TdR into HPLF-Y. During the confluent and quiescent phases IGF-I increased the incorporation of 3H-TdR into HPLF.
3) After a 12-day culture of IGF-I took place a markedly decreased alkaline phosphatase (ALPase)activity in the HPLF-Y. However, the ALPase activity of HPLF exposed to IGF-I increased approximately 196% during the confluent phase.
4) Proteins labeled with ³⁵S-methtionine (³⁵S-Met) of HPLF-Y and HPLF incubated with or without IGF-I were separated by an ion exchange chromatography (IEC-DEAE) and eluted with 0 to 0.5M NaCl in 20 mM Tris-HCI, pH 8.0 to obtain 4 fractions. The ³⁵S-Met labeled HPLF protein pattern was not altered by the addition of IGF-I. The II, III, and IV fractions of HPLF-Y exposed to IGF-I showed a decreased radioactivity of "S-Met labeled proteins. Autoradiography demonstrated in each fraction applied to SDS-PAGE bands labeled with ³⁵S-Met. IGF-I decreased the radioactivity of some bands of HPLF-Y, but not HPLF.
Therefore, IGF-I may regulate the growth and the differentiation of HPLF-Y cells and could modulate such aspects of cell differentiation as the ALPase activity and the synthesis of extracellular HPLF proteins.

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This report investigated 669 permanent-tooth restorations in 284 children who attended the Nagasaki University Dental Clinic of Pediatric Dentistry in 1994. Data resulting from the investigation were compared with those obtained in 1984.
Results and Conclusions
1. Of all the restorations performed in 1984,52.4% were composite resin fillings; 22.5% were amalgam fillings; 18.6% were metal inlays; 3.9% were stainless-steel crowns. In contrast to this, of all the restorations performed in 1994,76.7% were composite resin fillings; 11.1% were metal inlays; 6.7% were glass-ionomer cement fillings; 2.8% were stainless-steel crowns.
2. In 1994,96.0% of the anterior teeth and 72.7% of the molars and premolars were restored with composite resin materials. Young permanent teeth which were afflicted with caries extending only to the enamel or extending slightly into the dentin were restored preferentially with glass-ionomer cement fillings or composite resin fillings. Metal inlays were used preferentially for the two-surface or three-surface restorations of molars and premolars in the permanent dentition.
3. In 1984, for the proximal surface of decayed permanent molars and premolars,64.4% were restored with metal inlays,21.1% were restored with composite resin fillings,7.9% were restored with metal onlays and 6.6% were restored with amalgam fillings. In 1994, for the proximal surface of decayed permanent molars and premolars,53.9% were restored with composite resin fillings,40.9% were restored with metal inlays,2.9% were restored with metal onlays and 2.3%were restored with glass-ionomer cement fillings.
4. Compared with the results of 1984, the percentages of the composite resin fillings increased especially for the molars and premolars and no amalgam filling was used and glass-ionomer cement fillings were newly used in 1994.

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Dentin-bonding composite resins heve been widely used as a dental restorative material. However, due to the toxicity or pulpal irritation caused by the materials, there has been discussed as to whether it should be used with or without a liner in the cavity. An agar overlay cell culture method which recommended by FDI, was applied in this study to investigate the magnitude of the cytotoxicity of commercially available dentin-bonding agents and composite resins. The materials used in this study were as follows; 3 M: Multi-purpose, Z 100, Kuraray: Liner bond II, AP-X, GC: Bondwell-LC, Graft LC. The bonding agents were soaked in 4 mm diameter filter paper and the composite resins were filled in glass tubes (4 mm dia × 1 mm thick). Light was then applied with a light-activating unit (Visilux 2,3 M) through transparent celluloid strips (GC) with direct contact on the specimens at various light illuminaion times, just before testing. Fibroblasts 2 ml of 1 x 105 cells per ml in Eagle's MEM with 10% FCS, penicillin and streptomycin were evenly seeded on a cover glass (24 × 24 mm)in a tissue culture dish (35 × 10 mm) and incubated for 24 hours at 37°C in a humidified atmosphere of 5% CO, in air. After 24 hours of cultivation, the medium was replaced with 2 ml of agar overlay medium consisiting of Eagle's MEM with 10% FCS, and 1.5% agar. The test materials were placed at the center of the agar and incubated for 24 hours. After 24 hours of incubation, the cover glass was removed and the cells were fixed in 10% neutral folmalin and then stained with toluidine blue to differentiate the areas of affected and unaffected cells beneath the test specimens.
The affected areas was quantitatively determined using an image analysis system. The results demonstrated that the cytotoxicity of bonding agents and composite resins depend to great extent on light illumination time and the curring process. The cytotoxicity decreased remarkably with the longer light illumination time. The three kinds of bonding agents and composite resins used in this study showed no cytotoxic effect for test cells at 40 seconds of light illumination. At the adequate light illumination, the dentin-bonding agents and composite resins were converted into good biocompatible materials, which would not induce unfavourable pulpal reactions such as irritation and inflammation.

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The purpose of this survey was to investigate the parental attitudes and behavior concerning the dental health care of children who were under regular dental health care at the Pediatric Dental Clinic Tohoku University School of Dentistry. A questionnaire was filled out by the parents or the guardians accompanying their children aged from two years to eight years and eleven months of age at the recall visit. Concomitantly, oral hygiene and any other findings in the mouth were recorded by their dentists. Two hundred and forty-six surveys were obtained.
Eightynt-eight percent of the parents answered that the recall was necessary. The recall schedule at intervals of six months was approved by eighty-seven percent. For the question asking what the parents expected of the recall,97% chose caries inspection, this being the most frequent. Preventive procedures such as fluoride application or fissure sealant was expected by 70%. Fewer chose tooth brush instruction (38%) or dietary advice (6%). Ninety-five percent of the parents felt a sense of security by visiting the clinic periodically. While 42% of the children had some difficulties such as failure of filling, pain, soft tissue problems, or tooth injury after the previous recall, only 20% of their parents contacted the clinic to arrange for a visit immediately.
Seventy percent of the parents regarded brushing as most effective for preventing dental caries. Eighty-two percent of the preschool children were assisted in brushing by their parents, but this decreased to 54% among the school children, Fiftye-two percent of the parents answered that they had not modified the children's diet or dietary practices since they first visited the clinic.
Failure of the filling, newly developed caries, secondary caries, and gingivitis were detected in 15%,26%,9% and 13% of the children, respectively at the recall. Only 62% of the parents whose children had failure of the filling recognized it. A smaller percentage of parents recognized other difficulties.

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The follow-up study on the tooth morphology was conducted with the children possessing fused or congenitally missing anterior teeth in their mandibular primary dentition. The purpose of this study was to investigate the occurrence of tooth shape anomalies except fusion in the mandibular anterior teeth and their successors, and to compare the size and the development of the successors between the involved side and the uninvolved side among the cases in which fused or missing teeth existed unilaterally. Significant numbers of teeth showed some types of shape anomalies such as extremely rounded or disappeared angles of the incisal edge, indistinct cusp of the canines, flat contour of the labial surface, and diminished lingual ridges. The incidence of such anomalies was 87.5% in the primary dentition and 95.0% in the permanent dentition in this study group, which was significantly higher (p<0.01)when compared with a random sample of children having a complete tooth number (6.7% and 3.8%, respectively). Tooth shape anomalies were found not only in the involved side but also in the uninvolved side of the unilateral cases.
There was a wide range of variation in the mesiodistal crown diameter of the mandibular incisors and canines between the left side and right side among the children of this group, while the difference in tooth size between left and right ranging from 0 to 0.5 mm in the control group. In ten cases, for instance, that a primary lateral incisor and a canine were fused and a permanent lateral incisor was missing, five cases had a larger central incisor, four had a larger canine, one had a smaller central incisor, and three had a smaller canine in the involved side than the corresponding the tooth in the contralateral side, when the difference more than 1.0 mm was counted as larger or smaller.
The larger canines in the involved side demonstrated a crown shape more like a maxillary lateral incisor, suggesting the possibility of an undivided form of fused canine with a lateral incisor. On the other hand the smaller canines featured a peg-shaped tooth.
The development of the anterior teeth was evaluated based on the time of eruption and by the crown and root formation using panoramic radiography. Some canines in the involved side developed earlier than those in the uninvolved side. In 13 of 37 cases the canine in the involved side erupted more than a year earlier prior to the eruption of the other canine.
In conclusion, there was a wide range of variability in the shape and size of the primary anterior teeth and their successors among the cases in which fused or missing teeth existed in the primary dentition while the development of canines in the involved side tended to be accelerated.

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The biocompatibilities of new root canal fillings, CPO and CPE, composed of tetracalcium phosphate (4 CP) powder with either oleic acid or eugenol, respectively, were examined histopathologically and radiographically in 12 dogs. The root canals of 14 teeth per dog were filled with CPO, CPE or zinc oxide-eugenol (ZOE) and the periapical tissue reactions were evaluated 1,4,8,12 weeks after filling. Hard tissue formation was observed around CPO and CPE. Furthermore, the periapical tissue exposed to CPO revealed slight or moderate inflammation throughout the experimental periods, while severe inflammation was found in the periapical tissue around CPE. These findings suggest the usefulness of CPO as a root canal filling.

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The aims of this study was to clarify the problems of ready-made mouth guards that have been generally used and the necessary factors in the design of custom-mouth guards for the players of contact sports.
The subjects were 67 american foot-ball players attending university,21 rugby players and 4 boxing players attending senior high school.
We set up the questionnaire concerning the actual conditions of mouth guards, and examined the difference of occlusal pressure between placing the mouth guard and not placing it. Moreover, we performed spectrum-analysis of the voice under when mouth guard was in place and when it was not in place. The following results were obtained.
1. The typical replies submitted to the questionnaire were “incompatibility”, “speak with difficulty”, “feel like vomiting”, and “Breathe with difficulty”.
2. The occlusal pressure integral and the contact area at the maximum clenching decreased with statistical significant under use of the mouth guard compared with when not using it. However, the occlusal pressure per contact area at maximum clenching increased with use or the mouth-guard.
3. A part of the formant of the [i], [e] and [o] sounds which are a front and back vowels in [a], [s]and [t] series became unclear with both subjects who complained of “speaking with difficulty” and without difficulty after placing the mouth guard,. Moreover, the consonants of [s] and [t] disappeared in both subjects. These trends were remark able on the subjects with inarticulate pronunciation after placing the mouth guard.
These findings suggested that the ready-made mouth guard becomes rather a barrier to generalize than spread of the mouth guard. Furthermore, the improving on design at the palatal and labial side of the custom-made mouth guard recognized the need for generalizing the custom-made mouth guard.

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The purpose of this study was to investigate the influence of inhalation sedation using 30% nitrous oxide/70% oxygen on the change of the urinary catecholamine level in children during dental treatment. The subjects were 50 healthy children aged from 4 to 9, who received dental treatment with cooperative behavior during all procedures under inhalation sedation (sedation group) or non-sedation (non-sedation group). The sedation group consisted of 17 children, and the non-sedation group of 33children. For the purpose of analysis, each group was divided into two age groups; the younger group was composed of children aged from 4 to 6, and elder group was composed of children aged from 7 to 9. They received dental treatment, including infiltration anesthesia using 3% Citanest-Octapressin (without epinephrine), rubber-dams, cavity preparation and restoration.
The urine samples analyzed were collected before and after the dental treatment. Dopamine, noradrenaline and adrenaline were isolated from the urine and quantitative analyses were performed. The ratios of the post-treatment catecholamine levels for the pre-treatment catecholamine levels were calculated as the conversion ratio. The results were summarized as follows; In the younger children of the non-sedation group, the adrenaline, noradrenaline, and dopamine concentrations taken post-treatment were significantly higher than those taken pre-treatment. In the younger children of the sedation group, the adrenaline concentration taken post-treatment was significantly higher than that taken pre-treatment.
In the elder children of the non-sedation group, the adrenaline concentration taken post-treatment was significantly higher than that of pre-treatment. In the elder children of the sedation group, however, there were no significant differences between the concentrations of all indications taken pretreatment and taken post-treatment.
The conversion ratios of the dopamine, noradrenaline and adrenaline of the non-sedation group were significantly higher than those of the sedation group in both age groups. There were, in particular, statistical significant differences among the all of the indications of the younger children.
These results showed that catecholamine synthesis during dental treatment in children is depressed with inhalation sedation of nitrous oxide/oxygen. This tendency is more significant in younger than elder children.

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The cariostatic effect of low molecular dextran was examined in vitro and in vivo experiments. The dextran preparation promoted insoluble glucan synthesis by glucosyltransferases of Streptococcus sobrinus 6715 from sucrose. However, sucrose-dependent adherence of the microorganism to glass surfaces was inhibited significantly in the presence of the dextran preparation. In SPF SD rats infected with S. sobrinus 6715, the dextran preparation significantly inhibited the caries induction and plaque accumulation. These results indicate that the dextran preparation could serve as an anti-cariogenic food additive.

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Tetracalcium phosphate cement (4 CP cement) was modified for fissure sealant for erupting permanent teeth. The adhesion strength of 4 CP cement to bovine enamel, which was 31.5±7.7 kgf/cm², was a little higher than that of the Fuji Ionomer Type III® (Fuji III) used as a control. Furthermore,4 CP cements released more Ca and P to the outer solution and significantly promoted the remineralization of artifical demineralization lesions in enamel than did Fuji III. In addition,4 CP cement adhered to human teeth for as long as Fuji III. These results suggest that 4 CP cement is useful as a caries preventive sealant.

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The purpose of the study was to investigate the influence of the forced crossbites on the masticatory muscles in children. Children with mixed dentition having forced crossbites (n=19, FCB) were subjected and classified into two groups; i. e. the anterior crossbites (n=8, ACB) and the unilateral crossbites (n=11, UCB). Electromyographic examinations for the temporalis and masseter muscles bilaterally in the children with the forced crossbites and, as the control, with the normal occlusion (n =10) were performed during gum chewing on the habitual chewing side and non-habitual side, and/or crossbite and non-crossbite side. Muscle activity was integrated and evaluated by the activity ratio (%) in each muscle to the sum of the four muscles activities (the total muscle activity).
The results obtained were as follows:
1. When the ratio of each muscle to the total muscle activity was evaluated and compared among the groups, there were significant differences in the muscle activity pattern between the FCB children and the control, and between the ACB and UCB groups as well.
2. In contrast with the control which showed a higher activity on the working side in both the temporalis and masseter muscles, there were no differences in the activities of the ACB group between the working and balancing sides.
3. In the UCB group, there were significant differences between the chewing sides regardless whether there were crossbites or not. The working side of the temporal muscle during chewing on the crossbites side showed higher activity, but lower activity at chewing on the opposite side when compared to the balancing side.
4. As far as the muscle activity pattern was evaluated, the pattern for the chewing on the crossbite side in the UCB tends likely toward the control, while the pattern for the chewing on the crossbite side in the UCB and that of the ACB appeared quite different from the control.
The present study suggests that the muscle activity pattern of the FCB children is varied and depends on the location of the crossbites, ACB vs. UCB, and the physiological normal development of the masticatory muscles is presumably affected by the forced crossbites in children.

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The test video recording with images of a dentist, a hygienist, and the child subject's mother throughout it, which is an imitation of the field of vision of a child lying on his back in the dental chair during treatment, was showed to a child subject, and the child subject's ocular movements were recorded with Visicon Eyecamera.
Concerning voice, at the beginning of the recording, a moment of quiet was let to pass, “Open your mouth” was asked by the dentist, and a moment later “You are a good child” was said as praise by the mother and then “Try your best” was said as encouragement by the hygienist, and once more there was silence again before end. During this whole process, the quiet times were thought to be due to visual stimuli to the child subject, and the speech times were thought to be due to audio-visual stimuli.
According to the data observed from the Visicon Eyecamera, the point riveted on just before the speech time was termed as the final fixation point. Owing to the speech, the subjects who had fixed on the speaker were classified as the scanning group, or else the non-sanning group. Such items as the dentist's audio-visual stimuli caused subjects who had fixed on the dentist ever to be termed as, the dentist-scanning group, and so were the mother-scanning group and the hygienist-scanning group. The ratios of these 3 groups were caluculated respectively and were compared with each other. The findings were as follows:
1. As regards the final fixation point,23 subjects (48.9%) riveted their eye on the dentist and 24 subjects (51.1%) did not; 10 subjects (21.3%) riveted on the mother and 37 subjects (78.7%) did not; 13 subjects (27.7%) riveted on the dentist and 34 subjects (72.3%) did not.
2. Regarding the scanning group,36 subjects (76.6%) belonged to the dentist-scanning group and 11subjects (23.4%) did not; 30 subjects (63.8%) belonged to the mother-scanning group and 17 subjects (36.2%) did not; 24 subjects (51.1%) belonged to the hygienist-scanning group and 23 subjects (48.9%) did not.
3. There was a high significance (P<0.01) between subjects whose final fixation point was on the dentist and the dentist-scanning group, as well as between the mother and mother-scanning group. There was a significance (P<0.05) between subjects whose final fixation point on the hygienist and hygienist-scanning group.
In conclusion, with a dentist, mother and a hygienist within the field of vision of a child subject, who was lying on his back in the dental chair, and was talked to by either of mentioned 3 persons during treatment, speaker-scanning was the most noticed.

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Abstract: The purpose of this study was to investigate the relationship between eating behavior and the dental caries of the deciduous dentition among young children. The subjects were 667 3-year -old children, and their parents who attended on the days of dental checkups at 8 Public health centers in Tokyo. The relationship between eating behavior (The desire to eat, playing with food, chewing conditions, swallowing food whole, keeping food in one's mouth, taking food with suckling-like swallowing, ) and dental caries (caries pattern of attack, df-teeth) were analyzed by the χ² test and Mann-Whitney U test.
The main results were as follows;
1. The dental caries prevalence rate was 52.5 percent.
2. There were a few children who swallowed food whole and ate food with suckling-like swallowing.
3. A significant correlation was found between the caries pattern of attack and cases of eating behavior where food was kept in the mouth for longer periods of time.
4. Dental caries was more rampant in the above cases than among the other children.
5. A significant correlation was found between df-teeth and eating behavior that kept foods sometimes in their mouth.
6. No significant relationship was found between the df-teeth and the other kinds of eating behavior mentioned above.

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There are various factors related to first molar caries. In this study, we looked into the casuse-andeffect relationships between caries experience in each primary tooth during primary dentition and the initial caries occurrence in first molars, through a quantitative analysis by analyzing the data obtained from a 9-year follow-up survey of 432 children undergoing oral examination once a year in a rural community of Niigata Prefecture. The subjects were divided into 5 caries-free groups by the period in years of the initial detection of first molar caries from eruption, and each caries-free group was retrospectively looked into with 4 years of examination data of the respective primary teeth before first molar eruption was detected. Futhermore, a multivariate analysis (by means of the quantification method II) was performed between the caries-free groups and data of the respective primary tooth to determine the factors that might contribute toward first molar caries. The findings are as follows:
1. For the groups of 0- and 1-year with caries-free first molars, the average number of df teeth per child was above the total average number throughout the 4 groups. For the groups of 3- and 4-years with caries-free first molars, the average number of df teeth per child was below the total average number.
2. The higher the ratio of the number of caries-free teeth to that of carious teeth (including treated, untreated and missing teeth) during primary dentition, the longer the period of caries-free survival of the first molars.
3. In view of the correlation ratio, the highest value of each caries-free group (except for the 4-year caries-free group) was found in the 4 years before first molar eruption. Especially high correlations were found in the 0- and 1-year caries-free group in the 4 years before first molar eruption and in the 4-year caries-free group in the 1 year before first molar eruption.
4. Concerning the 0- and 1-year caries-free group in the 4 years before first molar eruption, there were strong correlations between first molar and primary lateral incisors, primary first molars, and the upper primary central incisor.
5. The longer the period of caries-free survival of the first molar, the stronger the correlations with the upper primary second molar during primary dentition.
6. Concerning the 4-year caries-free group in the 1 year before first molar eruption, caries-free survival of the primary lateral incisors and upper primary canine show strong correlations with the long period of caries-free survival of the first molar.

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Previous authors have reported eruptive gingivitis whenever the permanent teeth erupt. However, the actual conditions of the periodontium were not known at that time. The purpose of this study was to investigate the alteration of the periodontium, especially the eruptive gingivitis and alteration of the sulcus depth, whenever the permanent tooth eruption takes place. The subjects were the out-patients and the staff of Showa University Dental Hospital, Child Group,40 patients (Hellman dental age II C`III C)Adult Group I,14 patients (probing pocket depth 2`5 mm)Adult Group II,12 patients (probing pocket depth within 2 mm). The test location site was the upper central incisors, mesial buccal. The clinical conditions were evaluated using the Silness & Loe Plaque Index (P1-I), Löe & Silness Gingival Index (G. I. ), Probing Pocket Depth (P. P. D. ), and radiographs, after obtaining the parents consent. Perio-check® as a microbiological diagnostic technique, and phase-contrast microscopy were examined biologically. The results were as fbllows. The average pocket depth for the Child Group was 3.2±0.8 mm, the average Gingival Index-for the Child Group was 1.9±0.5, and at all of the test location sites there was found some inflammation. Statistically there was no significant difference in probing pocket depth between the Child Group and the Adult Group I. Statistically there was however a significant difference in the motile rods and spirochetes ratio, and in the positive ratio of the Perio-check® between the Child Group and the Adult GroupI. The motile rods and spirochetes ratio, and the positive ratio of the Perio-check® of the Child Group was close to the Adult Group II, so that, the gingival inflammation of the Child Group that suggested it was affected by the mechanism of the tooth eruption rather than with the plaque and subgingival microflora. Also, in the children whose teeth were in the variable eruptive stage, statistically there was no significant difference in P1-I and G. I., but the sulcus depth changed probably due to the Hellman's dental age, and to the root formation. The children's gingival inflammation was thought to be a phenomenon of the tooth eruption process.

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A hereditary ectodermal dysplasia of the anhidrotic type is also called the Christ-Siemens-Touraine Syndrome. It is transmitted as an X-linked recessive trait. The typical case of the congenital anomaly is characterized with the triad of the absence of the sweat glands, anodontia, and sparseness of hair. The four-year-old boy affected with the Christ-Siemens-Touraine Syndrome wore a removable appliance. Nine months later, the findings of the dental survey of his masticatory function, were as follows.
1. Poor cooling of the body temperature due to the absence of the sweat glands.
2. Sparseness of the hair of the head and eyebrows.
3. Deformity of the external ear.
4. Congenital missing of _??__??__??_and conical shaped crowns of _??__??__??.
5. Difficulty in chewing.
6. Enhancement of mandibular jaw movement, masticatory muscle activity and masticatory force.

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The dentigerous cyst is one of the most prevalent types of odontogenic cysts and causes an impaction of the tooth concerned and a dislocation of the adjacent teeth.
A-9-year old Japanese boy, whose maxillary central incisors had not yet erupted, was referred to Osaka University Dental Hospital. Radiographic examination showed a circular, well-defined and unilocular radiolucent area surrounding the crown of the maxillary left central incisor. The right central incisor was found to be displaced horizontally.
After marsupialization, both central incisors erupted naturally at the palatal side of the maxilla. These teeth were aligned with the normal dental arch by the direct-bonding system. However, the maxillary left canine which had erupted between the left central incisor and lateral incisor, was aligned transpositionally between them.3 years and 4 months after marsupialization, the dentigerous cyst had healed completely and good occlusion was established.

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Submandibular sialolithias is is a common case, but in chiidren it is rare. We reported a case of mandibular sialolithiasis, and examined the salivary calculus.
The results indicated maturity of the salivary calculus.
The posterior portion of the duct was the most mature, and anterior portion of the duct was semi mature. The middle portion of the duct was the most inmature.
The posterior portion of the duct formed rapidly. The secondary portion was anterior portion of the duct. The last portion was the middle portion of the duct.

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Recently we experienced luxation of A caused by a hit-wound in a boy 4 years and 1 month old. Clinical findings showed slight extrusion and tooth mobility, occlusion pain, and bleeding from the gingival sulcus. In the X-ray fingings, expansion of the periodontal membrane space was seen slightly but not distinctly. Bone fracture lines or fracture lines of the dental roots were not seen. Reduction and fixation between C were performed by the direct bonding method with the use of flexible quickpreparation adhesive resin and wire. Canal filling with paste was done by using calcium preparations and the prognosis was observed after removing the fixation.
About three years after treatment, root resorption of A was slightly delayed as compared with A. However, clinical discomfort or inflammatory findings in the X-ray examination were not found. Exchange with the succedaneous permanent tooth was completed smoothly. In the X-ray photos about four years after treatment, no abnormalities were found in the formation of the dental roots for both _??__??_a_n?d? _t he prognosis to date has been favorable.

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We often encounter trauma to the maxillofacial or oral region, and soft-tissue wounds occurring alone in children are frequent. Also children can suffer unusual injuries from objects held in the mouth, such as tooth brushes and toys. A case is described here in which trauma to the cheek resulted in herniation of the buccal pad of fat into the oral cavity. Although this tipe of case can be sometimes seen, has not been reported frequently in the current literature. On January 13,1993, a boy,4 years 4months of age, was brought to the Pediatric Dentistry Department of Kyushu Dental College Hospital. Earlier in the day he had fallen while brushing his teeth by himself. When his mother examined him, she observed a large reddish yellow mass protruding through the right buccal mucosa in his oral cavity. Closer examination of this mass revealed it to be the buccal fat pad exposed through its capsule. Our clinical examination revealed no abnormality other than the soft tissue injury. With the patient under local anesthesia, the fat pad was pushed through the laceration and into its capsule, which was approximated and repaired with four sutures. Follow-up examination 1 week,2 weeks, and 1 year later revealed no physical sequelae.

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In clinical pediatric dentistry, there are numerous cases encountered of abnormality in the number of teeth. The effect of abnormality in the number of teeth on the deciduous dentition and permanent dentition, and also on the state of the occlusion is great. We encountered a rare case where _??__??__??_were congenitally missing and a supernumerary maxillary median tooth was found in the same oral cavity of a 9-year-old boy. These congenitally missing teeth and the supernumerary tooth caused malalignment and occlusal disharmony. Treatment by occlusal guidance was completed during the three years and six months since the first examination.
(1) The patient is a boy,9 years and 10 months old, and came to our hospital with the chief complaint of esthetic impairment of the region of the anterior teeth. (2) The case was stage IIIB of Hellman's dental age. (3) _??__??__w?e?r_e congenitally missing and an inversed supernumerary tooth was found in the maxillary median region. (4)_??__??__??_ showed a slight crowding, and median diastema was found at _??__??. _(5_)? ?_T he anterior showed crossbite. (6) The treatment was completed with an occlusal guidance device using quad helix, chin cap, class III elastic, and the serial extraction method during the 3 years and 6 months since the first examination.

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Sialolithasis occurs due to the calculous concretion in salivary ducts or glands, but it is rare in childhood.
In this paper, a case of sialolithisis with a parotid gland calculous observed in 3-year and 10month old girl is reported. Subject is one of the youngest, based on a review of the literature regarding sialolthiasis found in Japan.
The retrospective survey was made in 23 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 12/11. There was no significant difference according to sex.
2) Location of the salivary calculi: In 20 cases they were found in the duct of the submandibular glands, and in 3 cases in the parotid glands, and in no cases in the sublingual glands.
3) Term before treatment: Most cases were treated within a month after the patients had 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 calculous was removed.
6) Size of the removed calculi: The diameter of the calculi was less than 5.0 milimeters long in most cases, but in two cases of the parotid duct they were more than 5.0 milimeters long.

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This is a case report concerning the replacement of the right maxillary central incisor involving total displacement due to a trauma and followed for four years and six months.
The patient was a five year, eight month old girl who was injured and visited the Pediatric Dental Clinic in Tohoku University Dental Hospital two hours after the injury.
When the avulsed tooth was brought in by patient, it was wrapped in dry paper and Only the coronal third of its root was formed and its apex opened.
The tooth was replaced without root canal treatment because of expectation of pulp vitality, and fixed with a clear resin splint.
There was no remarkable change by visual inspection compared with the adjacent central incisor. The pulp did not respond to an electric pulp tester at the first visit, but the pulp response was recovered 2 years and 3 months as well as 3 years and 3 months after the replacement.
Finaly, at 4 years 6 months, the electrical pulpal response disappeared, but, no discoloration was observed.

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Pulpal blood flow (PBF) in immatured permanent incisors after luxation injuries was measured with a laser Doppler flowmetry (LDF). Applications of the LDF for studying revascularization of the injured pulp and for the early diagnosis of the pulpal vitality are discussed in this paper.
Periodic fluctuations synchronous with heartbeat were present in all of the PBF signals of the vital permanent incisors in healthy children (n=11). For detecting the heartbeat synchronous fluctuations, PBF in the luxated upper central incisors was recorded simultaneously with an electrocardiogram (ECG) in two patients aged 6 y 5 m and 8 y 11 m. The PBF and ECG waveforms were analyzed using a power spectrum analysis and spectral peaks in the PBF signals corresponding to the heartbeat frequency were examined. This method presents advantages for assessing blood flow recovery in a luxated tooth because the PBF value is easily affected by the crown color, probe position, thickness of the enamel and dentin, etc. and these factors reduce the reliability of the net PBF values. One of the luxated teeth which regained sensitivity to electric pulp testing five months after the injury showed heartbeat synchronous fluctuations in the PBF signal in the early stage of the healing (one month after the injury). In contrast, the other luxated tooth which did not show heartbeat synchronous fluctuations in the PBF signals was diagnosed as pulpal necrosis nine months after the injury. Evidence for such a conclusion was found in increasing apical radiolucency. The tooth never responded to the electric pulp testings which were carried out during the follow-up period.
It is proposed that a reliable method for the early diagnosis of the pulpal vitality in luxated teeth would be to measure the blood flow with the LDF and to assess the heartbeat synchronous fluctuations in the signals through power spectrum analysis.

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