Male Wistar rats aged 6 weeks corresponding to the school-childhood period in humans were used. A low calcium diet was given for 3 weeks, resulting in bone loss, and was then changed to a normal diet for another 3 weeks, in the low calcium diet control diet group. The low calcium diet was given for 3 weeks, resulting in bone loss, and was then changed to a normal diet containing Ipriflavone for another 3 weeks in the low calcium dietnormal calcium diet (Ipriflavone mixture) group. The effects on the metaphysis of the tibia were investigated.
The results were reported as follows.
1. Densitometry
The low calcium group showed a significantly lower density than the control group, and the low calcium normal diet groups (p<0.01). The group with the low calcium, normal diet containing Ipriflavone showed a higher dentisty than the low calcium normal diet groups (p<0.01).
2. Histopathologic findings
Compared with the low calcium diet normal diet groups, the low calcium diet normal diet groups (with the ipriflavone mixture) showed a decrease in the width of the chondrocytic layer, an increased calcified matrix and erosion, of this indicating advanced endochondral ossification.
Based on these results, it was found that if the bone mass is fully achieved with a normal diet in the school childhood, period even though bone loss is induced, the recovery of the bone formation can be achieved by the bone formation promoting action of Ipriflavone.

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The purpose of this study was to investigate the relationship between caries activity tests, the status of dental caries and the habits of daily living in thirty one infants (21 boys and 10 girls) as these relate to the primary dentition.
The results were as follows:
1. The three types of streptococcus mutans tests correlated significantly with each other.
2. The streptococcus mutans tests correlated significantly with tooth cleaning habits and habits of eating between meals.
3. As Cariostat® correlated significantly with the status of dental caries and eating habits, it appears to be effective as the first means to check up on caries activity.

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A dental clinic attached to a maternity hospital had been opened in 1993 to provide oral health management for mothers and children. In this paper,1,098 women in childbed who were delivered of a child at the maternity hospital from April 1996 to October 1998 were investigated to understand the actual condition of the women. And 164 of the women in childbed and their children who participated in the two years old dental health screening at the maternity hospital were investigated to assess the relationship between the oral condition of a woman in childbed and her child. The following results were obtained.
(An investigation of the actual condition of women in childbed)
1. The average number of the DMFT index was 12.9 and the caries prevalence was 99.0%.
2. The average number of the DT index was 1.5 and 49.3% of all of the subjects had caries.
3. Sixty-seven percent of all of the subjects were a high risk based on the Cariostat test.
4. Seventy-three percent of all subjects showed to have calculus,79% gingival swelling,65% bleeding from gingiva and 75% accumulation of dental plaque. (The relationship between the oral condition of a woman in childbed and of her child)
5. There was a significant difference between the caries prevalence of children of mothers with caries and without caries during pregnancy.
6. There was a significant difference between Cariostat value of children of mothers with caries and without caries during pregnancy.

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Clinical isolates(1488 strains) of gram-positive streptococci were non selectively isolated from dental plaque of 16 Japanese children(age: 2-yr-olds-5-yr-olds), Streptococcus mutans and Streptococcus sobrinus in these isolates were detected and identified by the Southern hybridization technique using DNA probes specific to S. mutans and S. sobrinus. We also compared the detection ratios of the two species and caries prevalence in 16 children.
1) S. mutans was found in all 16 children (100%)
2) S. sobrinus was found in 13 out of 16 children (81.3%)
3) In 1488 clinical isolates, the detection rate of S. mutans was 10.9% and that of S. sobrinus was 5.2%. The detection rate of S. mutans was twice of that of S. sobrinus.4) Seven children who had both species of S. mutans and S. sobrinus showed a high caries prevalence. Although other children who had both species showed lower caries prevalence, they had several important factors that indicated they might shift to a high caries prevalence in the future.
These results suggest that existence of both S. mutans and S. sobrinus in the oral cavity may influence caries prevalence.

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This study was conducted in order to estimate the physiological tooth mobility in primary teeth.
The subjects in this study were 129 maxillary primary central incisors and 201 maxillary primary lateral incisors of patients between 2 years and 11 months-old and 9 years and 4 months-old. The teeth were clinically normal.These teeth were classified into 4 groups according to their degree of root resorption. The objective tooth mobilities were measured objectively by “Dental mobility checker®rdquo;.
The results were as follows: Among the primary central incisors, at stage 0, the mobility value was between 1.9 and 3.0 (average: 2.5). At stage I, the mobility value was between 2.1 and 3.8, (average: 2.8), and at stage II, the mobility value was between 2.1 and 6.4, (average: 4.0), and at stage IR, the mobility value was between 3.4 and 12.6, (average: 7.4). There were significant differences in tooth mobility among all of the stages (p<0.01).
Among the primary lateral incisors, at stage 0, the mobility value was between 1.9 and 4.5 (average: 3.1). At stage I, the mobility value was between 2.2 and 5.9, (average: 3.7), and at stage II, the mobility value was between 3.1 and 6.6, (average 4.3), and at stage III, the mobility value was between 3,7 and 14.9, (average: 7.9). There was a significant difference in tooth mobility between stage I and stage II (p<0.05). There were also significant differences in tooth mobility among the rest of the stages (p<0.01).
In conclusion, it is suggested that physiological tooth mobility in primary teeth is estimated objectively by the “Dental mobility checker®”.

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Hydroxyapatite is the principal component of human teeth and its crystallinity is one of the resistant factors against acid agents. A decrease in crystallinity would impair the resistance to acid and dental caries as well. The relationship between Ca/P ratio and crystallinity in human dentin is not yet well understood. In this study, the contents of Ca and P of human dentin were obtained by atomic absorption analysis and colorimetric analysis, and Ca/P ratios were then calculated. The crystallinity of the dentin was also analysis with micro-region X-ray diffraction. The relationship between the Ca/P ratio and crystallinity was discussed. The results were obtained as follows
1. According to the data obtained from 18 teeth the Ca/P ratios were found to be related to the tooth type and the location in the dentin.
2. No differences in the distribution of the Ca/P ratio in dentin with incomplete and complete teeth sets of teeth.
3. X-ray diffraction intensity of the crystalline varied depending on its location in the dentin.
4. It can be concluded that the Ca/P ratio was interrelated to the crystallinity in the dentin.

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The nested PCR-Southern blot method was established as a method of high sensitivity detecting of the Herpes Simplex Virus type 1 (HSV-1). The detection sensitivity which was 1-10pg/μl using the one step PCR method was able to increase even to 1×10-8pg/μl using the nested PCR-Southern blot method. It is expected that HSV-1 positive findings will be revealed to a greater extent than that of past reports.
The author examined whether not detected DNA of HSV-1 by the one step PCR method was found in saliva using the nested PCR-Southern blot method.
Saliva as the sample was collected from 6 children aged 2 to 11 years who suffered from herpetic gingivostomatitis and 7 children aged 5 to 10 years who were healthy without any manifested herpetic disease or other infectious diseases. All of the DNA was extracted from the saliva by NaI method, and the DNA of HSV-1 was amplified using the one step PCR method and the nested PCR-Southern blot method.
Above of all, it was suggested that the nested PCR-Southern blot method was useful for diagnosing the latent infection of HSV-1.

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For the development of good occlusion and healthy dentition of children, it is very important to understand the influences of the dental caries experience and malocclusion on the development of the occlusal function during infancy. In order to investigate the occlusal function, a longitudinal study was carried on 64 infants, the occlusal contact area, the occlusal force the mean occlusal pressure were measured using Dental Prescal®, and the condition of the occlusion were evaluated for a period of over 3 years in this study/ Each of the measurements was classified according to condition of dental caries and occlusion, and then compared annually. The results were follows:
1. Growth changes of the occlusal contact area and, the occlusal force in the malocclusion df, the df⋅df⋅df, the anterior cross bite and the open-bite groups showed a lower increasing value than the normal occlusion CF, the CF⋅CF⋅CF and the normal occlusion groups. Themean occlusal pressure in the CF⋅CF⋅df group at the third year showed a higher value than previous years.
2. There are higher values at the occlusal contact area and the occlusal force in the normal occlusion CF, the CF⋅CF⋅CF, the normal occlusion and the deep overbite groups for each year. In contrast, the lower values were observed in the malocclusion df, the df⋅df⋅df, the anterior cross bite and the open-bite groups. The mean occlusal pressure indicated a higher value in the malocclusion df proup and the CF⋅CF⋅df, the anterior cross bite, the open-bite groups at the third year and a lower value was observed in the deep over-bite group at the third year observations.
These results suggested that the dental caries experience and the malocclusion influenced the development of the occlusal function while growing up. It was also confirmed that dental health care for children needed to be aimed at prevention of dental caries and elimination of factors causing malocclusion.

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Tongue movements while sucking were studied using ultrasonography and a sucking pressure device. The subjects were seven cleft lip and palate patients (four with the Hotz appliance, three without it) and one normal infant. For sonographic observation, the probe was placed submentally, and tongue movements were recorded in both the frontal and saggital plane. In saggital plane M cursor line ran through the top of the article nipple, about 1 cm forward from the top, or about 2 cm backward, and tongue blade motion was observed respectively. Analyzing of the tongue wave consisted of measurement of the depth and time lag of three sites of the tongue blade motion. The depth, difference of the highest and lowest position of the tongue blade per sucking cycle, was measured in the M mode. According to differences in peaks of the tongue motion curves recoded in the M mode and peaks in the sucking pressure curve, the time lag of the three sites of the tongue blade motion was calculated. Moreover, hyoid bone movements were observed by placing the probe submentally. Swallowing reflexes were therefore identified clearly. The sucking movement of seven cleft lip and palate infants varied. The sucking cycle was prolonged in five subjects. The movements of all of the sites were noticeable in six subjects. Just for one person, the tongue pitched simply with little time lag. Three of the subjects using the Hotz appliance were not able to elicit the sucking reflex when it was removed. Only one person was able to suck both with and without the plate, and he made better movement with it. Using the ultrasonography M cursor and the sucking pressure device, we succeeded in assessing tongue movements while sucking.

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Zinc is a very important trace element, and it plays a manifest role in growth and development. In this study, the effects of zinc on the enchondral ossification at the metaphysis of the tibia in rats were observed.
Forty male Wistar rats, aged five weeks, were used. They were divided into four group as follows, the control group, the zinc deficient diet group, the low zinc diet (50%) group and the high zinc (150%) diet group. We obtained the results as follows.
1. Bone density
A significant difference was found between the zinc deficient diet group and the other groups, with the zinc deficient group showing a lower value. Between the low zinc diet group and the high zinc diet group, a significant difference was noted as well, with the high zinc diet group showing a higher value.
2. Histopathological findings
Compared with the control group, it was noted that in the zinc deficient diet group that there was an increase in the number of proliferate chondrocytes, irregular arrangement of the hypertrophic chrondrocytes, a decrease in the number of chondroclasts, a decrease in calcification, and a delayed ossification in the trabeculae and the thinner osteoid. Along with the increase in the volume of the intake of zinc, it was noted that there was a dense arrangement of chondrocytes and an increase in chondroclast. It was also found that there was active replacement from calfilage to bone and an increase in osteoblast and dense trabeculae. In the high zinc diet group those changes were very evident, which suggested more active enchondral ossification in this group than in the control group.
3. Hematological findings
Significant differences were noted in the serum level of calcium, the ratio of calcium to phosphorus and chloride between the control group and the high zinc diet group, between the zinc deficient diet group and the high zinc diet group, and between the low zinc diet group and the high zinc diet group. (p<0.01). In the high zinc diet group, CI showed significantly lower value among four groups. Significant differences were also found in the serum level of sodium between the zinc deficient diet group and the low zinc diet group, between the zinc deficient diet group and the high zinc diet group, and between the low zinc diet group and the high zinc diet group. The level of LDH in the low zinc diet group was lower than in the control group, while ALP noted a significant difference between the control group and the zinc deficient group, and between the zinc deficient group and the low zinc diet group (p<0.01).
Based on the foregoing results, it has been shown that the zinc deficit would result in an inhibition of enchondral ossification in the tibia of rats and the increase in the volume of the intake of zinc had a beneficial effect on bone formation.

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A new salivary buffer capacity test (CAT 21 But) was developed. This study was conducted to investigate the relationship between the salivary buffer capacity test with the caries status in preschool children.
The following results were obtained;
1. The rations of preschool children who were able to take stimulated saliva more than 1.0 ml amounted to 20.7% at the age of 4,57.1% at the age of 5,67.7% at the age of 6 years, respectively.
2. The caries prevalence and the mean df-teeth of the preschool children aged 6-years was 61.2% and 3.39, respectively.
3. When the salivary buffer capacity test (CAT 2 IBuf test) was divided into three groups (low risk/middle risk/high risk), it showed a highly significant correlation with the df-teeth (p<0.01).
4. The high risk group had a higher caries prevalence than the low risk group but the caries prevalence among each group did not show any significant difference.
5. The high risk group had a higher mean df-teeth than the low risk group and the mean df-teeth among the each groups showed a significant difference (ANOVA p<0.05). Based on these results, it is suggested that the salivary buffer test was useful for clinical application.

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The aim of this study was to provide information related to the average pattern of occlusal force distribution in the deciduous dentition using pressure sensitive sheets, DENTAL PRESCALE ®( Fuji Photo Film, Co., Japan).
Occlusal force was measured in 42 healthy children who had normal occlusions. The distribution of occlusal force was expressed as a percentage of the total occlusal force for each tooth. The symmetry of the occlusal force distribution was shown by an asymmetry index, defined as the percentage of the difference between the right and left occlusal force in relation to the sum ([R-L]/(R+L)×100[%]). The results obtained were as follows;
1) No differences in either occlusal forces or occlusal force distribution were found between boys and girls.
2) The average of the total occlusal force was 430.6 N, and the average of the total occlusal force of each tooth by the primary 2 nd molars was 129.5 N, by the primary 1 st molars 46.4 N, by the primary canines 23.8 N, by the primary lateral incisors 9.5 N and by the primary central incisors 6.1 N.
3) The distribution of occlusal force by the primary 2 nd molars was 60.9%, by the 1 st molars 21.5%, by the primary canines 11.0%, by the primary lateral incisors 4.0% and by the primary central incisors 2.6%.
4) The average asymmetry index of occlusal force distribution was 8.9%±6.5(%), Based on these results, it was suggested that in deciduous dentition the distribution of occlusal force is concentrated on the primary molars, in particular on the primary 2 nd molars that exert most of the occlusal force in the deciduous dentition.

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Since application of pit and fissure resin sealant has been proven to be effective as a caries preventive measure, particulary in pediatric dental practice, it has been widely used for more than a quarter of a century.
In this study, we used a light cured fluoride slow releasing sealant (Teethmate-F1®), which contains about 1 wt% fluoride and gradually releases the fluoride through hydrolysis. This sealant thereby provides not only mechanical protection of the caries susceptible pits and fissures, but also enhances the acid-resistance of the adjacent as well as the area underneath the acid-etched surface enamel, by supplying fluoride ions.
Four hundred and eighteen permanent molars and premolars of 151 children who visited our Pediatric Dental Clinic, were the subjects of the study. We clinically evaluated the retention rates of the sealant as well as the caries prevention in these teeth after 1-year-1-month on average. The retention rate of this sealant was 83.5%, and partial retention rate was 12.9%, whereas none of the carious lesions were detected.

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The aim of this study is to examine the reliability of the modified method by sampling without paraffin wax chewing in 84 infants and young children aged 2-5 years old. The Dentocult-SM® Strip mutans score made by the modified method using the sample without paraffin-wax chewing (DSMs-M)coincided with 55.8% with the score made by the original method (DSMs-O). In case of containing a score of ±1. DSMs-M coincided with 85.3% with DSMs-O in the group under 4 years old. The coincident rates in the group over 4 years old between DSMs-M and DSMs-O were 44.0% and 78.0% respectively. The Dentobuff® Strip score made with the modified method (DBs-M) coincided with 28.6% in the group under 4 years old and 28.3% in the group over 4 years old with the score made by the original method (DBs-O). Over 95% of the DBs-O was score 3 (high). DSMs-M correlated significantly (p<.0001) with DSMs-O by means of Peason's correlation coefficient and the Speaman correlation coefficient in both age groups. Meanwhile, DBs-M did not correlate significantly with DBs-O. DSMs-M and DSMs-O correlated significantly (p<.01, p<.05) with the caries index (CSI and dmf) in the group under 4 years old. In the group over 4 years old, only DSMs-O correlated significantly (p<.05, p<.01) with the caries index (CSI and dmf). In conclusion, it was suggested that Dentocult-SM® Strip mutans made by the modified method in this study is very useful and reliable in the group under 4 years old. However, we doubt the effectiveness of Dentobuff® Strip made by the original method without specificity as a Caries activity test based on comprehensive analysis of our results.

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We conducted a follow-up study of proximal caries in 232 permanent teeth of 82 patients who visited the Department of Pediatric Dentistry, School of Dentistry, Iwate Medical University for 6 years (during the period of 1995-2000). Based on the direct examination the patients were found to have no decayed hard tissues but caries were found using the bite wing x-ray. Moreover, thirty-four teeth of 23 patients who visited the hospital in 2000 were studied to examine the background for the progression of caries, using the caries activity test, salivary test, contents of teatime snacks, the condition of oral hygiene and number of teeth experiencing caries. The results obtained were as follows:
1) As for the type of teeth, the mandibular second premolar was the most frequently decayed, followed by the maxillary second premolars, and the maxillary and mandibular first molars.
2) As for the number of cases at the different ages, the incidence of caries was increased from 9- to 18-year-olds. The most frequent age to develop caries was at the ages of 14 and 15.
3) The age when discoloration of teeth was found was the adolescent period, and bite wing x-rays were frequently taken.
4) For carious teeth with more or less than 1/2 of the enamel indicated by x-ray, most teeth were under periodical observation. Thirty-eight point eight percent of the teeth which developed caries with less than 1/2 of the dentin were under periodical observation. All of the teeth with caries more than 1/2 of the dentin finally underwent caries treatment.
5) The reason proximal caries were found frequently for the premolars, may be due to patients having some problems in school life, club activities or had been mentally unstable in their adolescent period; as well as poor self-cleaning in the proximal area of premolars due to the pressure from posterior molars. We emphasize that it is important to reexamine the enamel caries in the proximal area and the prevention of proximal caries of the children in the adolescent period.

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The objective of this study was to explain importance of early treatment for functional lateral crossbite in primary dentition, and to explain results with treatment using Quad Helix.
We examined the teeth, dental arch forms and occlusion using upper and lower plaster models, The results were as follows;
1. Compared with the lower arch forms, the upper arch forms were narrower and the lower arch forms shifted with premature contact of the primary canine.
2. Because the midline of the upper arch expanded laterally matched those of the lower arch and occlusion was correct on both sides, the shift of the lower arch forms was improved.
3. Occlusal management from primary dentition is important for the normal growth of the dentition and jaw.

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This study was undertaken to investigate the effect of the Xenon-lamp curing unit (Flipo) on the elemental properties of light curing resin composite by comparison with a halogen-lamp curing unit (XL).
1) The shear bond strengths of resin composite to bovine dentin using each curing unit were measured. The adhesive system and resin composite used in this study were Clearfil Liner Bond II® and Clearfil AP-X® (shades: A 2 and A 4). The irradiation time of XL was 40 seconds as the control, and that of Flipo was 5 seconds (stepped output of 2 seconds at 50% maximal output followed by full output for 3 seconds). The result of the test showed that the shear bond strength produced by Flipo was about equal to that by XL for shade A 2, but for shade A 4 that produced by Flipo was significantly lower than that by XL (p<0.01). Using XL showed high bond strengths independent of shade.
2) The knoop hardness of the resin composite was measured for XL for 40 seconds, Flipo for 5 seconds and Flipo for 10 seconds (2 seconds at 50% maximal output followed by full output for 8 seconds)using Clearfil AP-X® (shades: A 2 and A 4). The result showed that when the shade was A 2, the knoop hardness produced by Flipo for 5 seconds was about equal to that by XL for 40 seconds, and that of Flipo for 10 seconds was significantly higher than those two groups (p<0.01). For shade of A 4, the knoop hardness produced by Flipo for 10 seconds was about equal to that of XL for 40seconds, and that of Flipo for 5 seconds was significantly lower than those two(p<0.01).
3) The dye penetration test was performed for cavities prepared on extracted human premolar and filled with resin under the light curing condition of XL for 40 seconds, Flipo for 5 seconds (two stepped output) and Flipo for 5 seconds of exposure at 100% intensity to evaluate marginal sealing and wall adaptation. The class V cavity with the base at depth of 1 mm in the dentin was prepared on the buccal surface. The group of XL for 40 seconds showed the best marginal sealing and wall adaptation, but when using Flipo at 100% intensity for 5 seconds, the dye penetration score was higher and both the incidence and width of contraction gap were significantly increased. The results of the present experiment proved that using the Xenon-lamp curing unit (Flipo) is effective for hardening a resin composite of shade A 2 less than 2.0 mm-deep with 1/6 of irradiation time needed for the halogen-lamp curing unit (XL). However, if the cavity is deeper than 2.0 mm, sufficient polymerization may not be obtained by using Flipo for 5 seconds, especially for shade A 4, and moreover, using Flipo for 5 seconds at 100% intensity may degrade the marginal seal effectiveness and wall adaptation.

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Replantation was performed on the maxillary second incisors bilaterally. The pulp was removed from the experimental teeth on the right 5 weeks after replantation, and they were filled with calucium hydroxide. The teeth on the left teeth, from which the pulp had not been removed were used as controls. The teeth were clinically monitored by measuring the mobility and the gingival index, and intraoral photography and standardized X-ray were also performed. A non-decalcificated polished specimen was fluorescence-labeled for histological observation, and the changes in the replanted teeth and the periodontal tissues were evaluated with microradiography, fluorescent microscopy, and polarizing microscopy.
1) No significant difference was observed in terms of tooth mobility or the gingival index between the experimental and control teeth until 5 weeks after replantation. After root canal treatment was performed 5 weeks after replantation, however, the control teeth showed high mobility and a high gingival index, with significant differences between the two groups.
2) The periodontal space of the experimental teeth was hourglass-shaped, wide in the cervical portion and the root apex, and narrow at the central root, For the control teeth, on the other hand, the periodontal space was uneven and functional tissue morphology was lost.
3) Periodontal fiber regeneration was observed in the experimental teeth, there was however, little regeneration among the control teeth.
4) Hard tissue was observed at the root apex and the surrounding alveolar bone in the experimental teeth. Inflammatory absorption was observed in the control teeth.
From a clinical and histopathological standpoint, the results suggested that root canal treatment performed 5 weeks after replantation provided a favorable outcome.

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There are many stressful elements during dental treatment. It is important to know the influence of this stress. Many studies have investigated the stress from the psychological point, behavioral point and physiological point. It is, however, unknow what the behavior caused by psychological changing means from the viewpoint of physiology. The purpose of this study was to investigate the relationship of behavior caused by anxiety and the nasal skin temperature. The subjects of this research were the 96 pediatric patients (47 boys and 49 girls). The anxieties were measured by Japanese version of the State-Trait Anxiety Inventory for Children and the Dental Fear Survey modified by Yoshida. The behavior and the progress of the dental procedures were observed with two video monitoring cameras. The nasal skin temperature was measured and recorded using a thermograph. The results showed that the anxiety was reflected on behavior during dental treatment and a relationship was between the state of anxiety and the nasal skin temperature. It was also recognized that behavior was related to the nasal skin temperature. It was found the relationship of the movement of the upper half of the body and the nasal skin temperature was shown in particular. The possibility was suggested that behavior during dental treatment worked to cope with stress and it reduced the coefficient of variation of nasal skin temperature.

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The purpose of this study was to investigate whether biting pressure and masticatory efficiency depended on the occlusion types in children with primary dentition, or not. The subjects were 130 children from 3 to 6 years of age. They consisted of 68 children with normal occlusion,19 children with deep bite,15 children with edge to edge bite,5 children with vertical open bite,19 children with horizontal open bite and 4 children with anterior cross bite. The masticatory efficiency all of the subjects was measured using the ATP spectrometric method and the bite force using the measuring system of the occlusal pressure (Dental Prescale®). Data for each occlusion types were compared with the normal occlusion group. Furthermore, the relationship between the bite force and masticatory efficiency and the relationship between the occlusal contact areas and masticatory efficiency were investigated among the groups of each occlusion type. The following results were obtained:
1. Masticatory efficiency in the deep bite group showed significantly lower values than in the normal occlusion group. There were no significant differences in masticatory efficiency between the groups of the other occlusion types and the normal occlusion group.
2. The values of the occlusal contact area and occlusal force in the deep bite group were significantly lower than in the normal occlusion group. In the posterior tooth site of each malocclusion group, the occlusal contact area, occlusal force and average occlusal pressure did not show significant differences compared with the normal occlusion group.
3. In the normal occlusion group, there were significant correlations between the bite force and masticatory efficiency (r=0.330) and between the occlusal contact area and masticatory efficiency (r=0.340). On the other hand, no significant conrrelation between these parameters was found in the malocclusion groups.

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The aim of this study was to evaluate the effect of parotid saliva on the rate of salivary clearance on the upper posterior buccal surfaces. To determine the exact position of the parotid duct opening, alginate impressions were taken of the upper jaw and stone models were made. Subjects for whom the parotid gland opening position was almost identical were selected. To determine the rate of potassium chloride clearance,1 mol/l KCl in a 1.0% agarose matrix was used as the diffusant, which was placed in acrylic devices. The diffusion chambers were taken from the mouth at selected time intervals and the gels transferred quantitatively to flasks containing 300 ml of 100 ppm NaCl, and then analyzed for potassium using atomic absorption spectrophotometry. The velocity of the salivary film at the upper posterior buccal surface of the tooth was also estimated with this equipment, which designed by Dawes.
The following resulte were obtained:
1. The opening position of the parotid duct in 13 subjects showed a large degree of deviation
2. The rates of salivary clearance at the second premolar, first molar and second molar of the upper jaw differed significantly from each other, and the highest value was found at the first molar.
3. The direction of salivary flow from the opening of the parotid duct was forward in the unstimulated salivation and backward in the stimulated salivation.
4. The estimated velocity of the salivary film varied with different tooth surfaces, and the highest velocity was found for the first molar.

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In recent years, prematurely born, very low birthweight children (VLBW,<1500 g) have shown increased survival rates and greatly improved outcomes because of the increasing sophistication of neonatal care. However, as they were given nutrition through tube feeding for several months in a neonatal intensive care unit (NICU), the development of the oral function and/or the gnathofacial morphology was expected to be somewhat affected. The purpose of the present study was to investigate the development of the oral function (sucking, mastication) in children with VLBW using a quesionnaire answered by their mothers.
The subjects were seventy-eight children aged 2 to 4 yrs who had been treated at the NICU of Gifu Hospital, due to premature birth and matched with 62 healthy normal birthweight (NBW) controls. The low birthweight children were dived into two groups such as the low birthweight (LBW,<2000g,44 children) group and the very low birthweight (VLBW, including the extremely low birthweight <1000 g,34 children). The questionnaire consisted of 33 items, such as 5 items concerning sucking problems or ability,18 items concerning masticatory problems or ability and 10 other items. The ttest or chi-square test of the subject, wherever appropriate, was used for data analysis.
While there was no significant difference between the LBW and NBW groups, significant differences were found between the VLBW and NBW groups in the following areas; such as sucking problems after leaving the hospital, at beginning of weaning, at beginning of eating ordinary foods, unbalanced diet, frequency of pacifiers and verbal development.
In conclusion, it is suggested that the rates of feeling problems accompanying the development of the oral function was higher in mothers who had VLBW children than those who had the NBW and LBW children. For this reason, we dentists have to pay attention to the development of the oral function of the VLBW children and to examine them periodically.

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This study was conducted to compare the durability of restorations for the primary teeth and the effect of caries prevention on permanent teeth of the recall group with the control group. The recall group was composed of 88 children with 622 dental restorations in the primary molars whose first visit to a dentist was at the age of 1-5 and had regular oral health check-ups until the age of 12.
The control group was composed of 151 children with 1128 dental restorations in the primary molars whose first visit to a dentist was at the age 1-5, and never had regular oral health check-ups until at the age of 12.
1. With the recall group, the percentages of usable restorations in the primary molars of the children were 84.6% after one year,65.7% after two years, and 50.6% after three years. The number decreased to less than 50% in about three years. The control group was 74.1%,48.2%,32.4%, respectively. It was less than 50% after about two years. (chi-square test p<0.01)
2. With the recall group, the average time of dental treatment to place a restoration in a primary molar was 1.81 and at the control group was 2.41. The recall group showed less time required for dental restorations than the control group. (ANOVA p<0.001)
3. With the recall group, the average duration of the first restorations in the primary molars was 3.30years and with the control group was 2.48 years. The recall group had a longer duration for the restorations than the control group. (ANOVA p<0.001)
4. With the recall group, the mean DMF-teeth was 2.39 at 12 years of age, and with the control group was 4.52. The recall group showed lower number of caries teeth than the control group. (ANOVA p<0.001)
These results suggested that the recall system was effective for the durability of the restorations of the primary teeth, and was effective for the prevention of caries of permanent teeth in the dental clinic.

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It would be ideal if we could analyze eye movement in three-dimensions in the clinic in the study of visual perception. We have not established the method, however. It is possible to analyze binocular eye movement in three-dimensions using the binocular eye movement measuring apparatus TKK 2901®in theory. We suspect however that some inaccuracy exists. Therefore we made a study to test the accuracy in the apparatus. As a result, we arrived at the following conclusions.
We have interpreted that fixation point means the center of attention as before. After we examined the fixation point in three-dimensions however we found a difference between the calculated number and the measured number of fixation points. We therefore found that the fixation point means the direction of one's visual axis in some cases.

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Osseous lesion of the tongue is relatively uncommon. A 5-year-old girl was referred to the Dentistry of Chiba Children's Hospital, because of a nodule of the tongue. The lesion was approximately 7 mm in diameter and located superficially at the left side of the tongue and just anterior to the circumvallate papillae. Based on CT examination, a dense round mass was seen at the posterior region of the tongue. The mass had a density of 437 Hounsfield units on the CT images, indicating an osseous lesion and it was excised under general anesthesia. The nodule showed 7×7×4 mm in size. Microscopic examination of the specimen revealed that the nodule was composed of lamellated bones and lay directly beneath the stratified squamous epithelium. The histopathological diagnosis was osseous choristoma.
Although osseous lesions of the tongue had been mostly reported as osteoma before 1970, it is often now, referred as osseous choristoma. We compared 19 cases of osteoma and 44 of osseous choristoma of the tongue in the literature. Both groups were found to be the same entity in every respect as to location, pathologic features, size of tumors, ages of patients and male-female ratio. It was therefore considered that osteoma and osseous choristoma of the tongue were the same lesion.
1) The ages of the patients range from 5 to 73 years, and the mean age of patients is 27 years and 9months. The male-female ratio is 1: 3.
2) The size of tumor ranges from 4 mm up to 45 mm in the largest dimension. The average size is 10mm in the largest dimension.
3) Most tumors are firm and pedunculated, existing in the dorsal surface near the circumvallate papillae of the tongue.
4) According to histologic examination, osseous choristoma is composed of a mass of wellcircumscribed, lamellated dense bone with definite Haversian canals.
5) No essential differences between choristomas in children and adult were noted except for the size of the tumor.

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Peutz-Jeghers syndrom is an autosomal dominant inheritance disease characterized by polyposis of the gut and pigmentation of the lips and oral mucosa.
A 4-years-1O-months-old boy having an intraoral pigmentation had visited the Clinic of Pedodontics, Kobe Children's Hospital. And he was refered to the surgery with the suspect of Peutz-Jeghers syndrom, and has been checked periodically there for polyps. When he was 9-years-8-months,11years, and 11-years-7-months-old, polyps were found in his stomach, sigmond colon and/or recutum, and they were all removed by endscopic recection, After that he progressed favorably without recurence of any polyps. In the dental Clinic, therefore, any patient found to have an intraoral pigmentation should be refered to the, surgery with the suspition of the Peutz-Jeghers syndrom.

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This report describes two cases of preeruptive dentinal defects with a small pulp exposure. In these cases, radiographs taken previously suggested that the defects were not present when the dental crowns of the affected teeth were completely formed.
One case was an 8-year-old boy. Clinical examination revealed a recently erupted maxillary right central incisor with a large defect on the mesial and lingual surface. The defect was 5 mm wide and 6mm long, and was filled with a soft tissue associated with gingival tissue. The tissue was curetted away, revealing a small pulp exposure.
Another case was a 10-year-old girl. A bitewing radiograph taken for the recall examination revealed a radiolucent area in the coronal aspect of the unerupted mandibular right second molar. The tooth was covered completely by gingival tissue. The crown of the affected tooth was surgically exposed under local anesthesia, revealing a normal occlusal surface with a intact enamel surface that could not be penetrated with a sharp dental explorer. When the intact enamel on the occlusal surface was removed, an empty large defect with a small pulp exposure was observed in the dentin.
Both cases were treated by direct pulp capping with calcium hydroxide powder in sterile saline, followed by a glass ionomar interim restoration. They were followed up over the next 2 years. All clinical and radiographic features indicated normal pulp vitality and normal root formation. It was most likely that in these cases, the defects of the crowns were resorptive lesions, because they were progressive, but the etiology of the coronal resorption was unknown.

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Dental care for a patient with maxillary protrusion and constriction of the upper dentition caused by oral habits was conducted for correction of the malocclusion as well as the oral habits, by using a removable biteplate with a lateral expansion screw. The patient used this appliance from 9 years-7months of age to the permanent dentition period. After using a retainer for I year-10 months, the treatment resulted in an esthetically and functionally established permanent occlusion, without any relapse of the oral habits.

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Dental care for two Japanese girls who had bimaxillary protrusion caused by swallowing habits, was performed with the removable appliances.
Case 1 At 8 years-0 months of age, a removable biteplate was used for breaking the swallowing habits along with the nail biting and lip biting habits, while correcting the bimaxillary protrusion. Since her tongue protruded over the plane of the appliance, a fence was added to the biteplate at 8years-9 months of age. She used this appliance for 2 years-11 months, and the oral habits as well as the bimaxillary protrusion were corrected. After using a retainer for 1 year-9 months, the treatment was completed.
Case 2 At 8 years-11 months of age, a removable biteplate with a fence was used for breaking the swallowing habits and correcting the bimaxillary protrusion. Since the oral habit was broken at 11years-7 months of age, the fence of the biteplate was removed. She used this appliance for 4 years-1month, and the bimaxillary protrusion was corrected. She has been using a retainer and has been observed periodically.
In these two cases, habit breaking using the biteplate corrected the axial inclination of their bimaxillary incisors, and esthetically acceptable as well as functionally sufficient permanent occlusions were established.

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Dental treatment was carried out on a 6-year old boy with asthma, atopic dermatitis, and tick-moldfood allergy. Before the dental treatment, several allergic tests were performed to check which dental materials were suitable for the patient. He was treated at another hospital with glass-ionomer-cement as the temporary filling materials for caries. After the treatment, he had a routine medical checkup.
He was suspected of having hypersensitivity to dental materials, since the selective synthesis of IgE antibodies for milk had a sharp rise from score 3 to score 6. On the advice of his pediatrician, he came to our hospital to have minute allergic tests and treatments for caries.
We carried out several allergic tests as follows.
1. Patch tests for 18 dental materials
2. Scratch tests for 2 types of local anesthetic solutions
A strong positive skin reaction, such as erythema, edema and vesicle, was elicited with the selfetchingprimer, A positive reaction resulted from the etching agent. The anesthetic solutions and the other dental materials (including glass-ionomer-cement) did not induce skin irritation.
We suspected that he was sensitive to the self-etching-primer. We, therefore, did not use composite resin as the filling materials. Silver alloy inlay and titanium primary crowns were selected for the dental treatment.
No untoward event was noted throughout our dental treatment, and no adverse reactions were noted postoperatively.

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Congenital generalized lipodystrophy (CGL) is a rare disease and is the result of an autosomal recessive gene made manifest by atrophy and disappearance of the systemic subcutaneous adipose tissue.
Growth promotion, hypertrichosis, cutaneous pigmentation, and insulin resistant diabetes mellitus are recognized as systemic findings in CGL. Although such pathogeneses are indistinct there are no fundamental therapies.
There have been no previous reports regarding the longitudinal changes in the disease.
In this study, the longitudinal changes and the oral findings of the CGL patients who attended our clinic, are reported. The oral findings observed were as follows.
1. Early calcification of the permanent teeth and early eruption 2. Enamel hypocalcification of the permanent teeth 3. Anomalies of the dentition and occlusion 4. Periodontal disease 5. Labial hypertrophy 6. Macroglossia and furrowed tongue 7. Uvula bifida 8. Palatal tonsil and adenoid hypertrophy
The present symptoms of gingivitis were noticeable, and the permanent dentition will soon be completed. An Orthopamtomogram revealed that the alveolar bone showed gradual absorption. The periodontal disease worsen with increased age, and mobility of the teeth was observed.

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We experienced a case of amelogenesis imperfecta with deciduous dentition and provided not only clinical examination and treatment but also a laboratory test for identification of the mode of inheritance using DNA examination of human amelogenin gene (AMGX) for the patient. The findings were as follows:
1. A 3-year-old Japanese male was evaluated with a chief complaint of severe sensitivity causing by enamel defects. Based on clinical examination, we found that the patient had defective enamel on all of the primary teeth present. The patient had severe loss of enamel particularly on the primary molar teeth that had little enamel exposing dentin. The enamel had been chipped away at the incisal edge and labial surface on the anterior teeth. The enamel was found to be relatively soft by probing and appeared to have normal thickness and weak radiodensity. As the past medical history was unremarkable for any systemic, metabolic, or endocrine condition, a diagnosis of amelogenesis imperfecta was established.
2. Full coverage with stainless steel crowns was provided for the primary first and second molar on both of maxilla and mandible, which had severe sensitivity due to loss of protective enamel. This treatment removed the severe sensitivity. Successively, composite resin was used to cover the exposed dentin on the anterior teeth. The patient was provided with three-month recall schedule for preventive treatment.
3. The family history of this disorder was unclear for diagnosing the mode of inheritance of this disease. To obtain the mode of inheritance, the structure of the AMGX gene was analyzed using the molecular biological technique. Consequently, no differences were obtained in the sequence of the seven exons of AMGX between the affected patient and individuals with normal teeth. This finding suggested that the patient did not have any mutation in the seven exons of AMGX, so that the autosomal inheritance pattern was expected, excluding X-linked inheritance.

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