To examine the craniofacial growth pattern in children with normal occlusion and malocclusion, the authors analyzed craniofacial angular characteristics at ages 6,9,12 and 16 with longitudinal lateral cephalograms in 42 Canadian Caucasian boys at The Burlington Growth Center in University of Toronto.
Bimaxillary protrusion, maxillary protrusion and mandibular retrusion are recognized as Class II malocclusion. Using lateral cephalograms and study casts, we prescribed over 85K in SNA and less than 5K in SNB as bimaxillary protrusion, over 85K in SNA and over 5K in SNB as maxillary protrusion and less than 85K in SNA and over 5K in SNB as mandibular retrusion, and less than 85K in SNA and less than 5K in SNB as normal occlusion at 16 years of age. The results were as follows.
1) The mean values of SNA in the bimaxillary protrusion and maxillary protrusion groups were significantly larger than those in the normal and mandibular retrusion groups. Only the maxillary protrusion group was significantly increased with age.
2) The mean values of ANB in the maxillary protrusion and mandibular retrusion groups were significantly larger than those in the normal occlusion group at ages 6,9 and 12. Those of the normal occlusion and maxillary protrusion groups decreased significantly with age.
3) The mean values of the Angle of Converxity in the maxillary protrusion were significantly greater than those in the normal occlusion at ages 6 to 16.
4) The mean values of the A-B plane angle in the maxillary protrusion group were significantly larger to the -side shift than those in the normal occlusion group at ages 6 to 16.
5) The mean values of SNP in the bimaxillary protrusion group were significantly larger than those in the normal occlusion group at ages 6,9 and 16. In mandibular retrusion group, the mean values of SNP were the smallest among the four groups at ages 6 to 16, and which growth change with age was seldom observed.
6) The mean values of the mandibular plane angle in the mandibular retrusion were larger than those in the normal occlusion group at ages 6 to 16.
7) The mean values of GNZ in the mandibular retrusion group increased with age, in which the value was significantly larger than in the normal occlusion group age 16, and the mandible position in the mandibular retrusion group was more posterior compared to the other groups.

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To clarify the difference in growth change of the craniofacial size between normal occlusion and malocclusion, the authors analyzed the linear and square measurements of longitudinal lateral cephalograms at 6,9,12 and 16 years old boys, the same material as in the first report at the Burlington Growth Center in University of Toronto. We prescribed over 85° in SNA and less than 5° in SNB as bimaxillary protrusion, over 85° in SNA and over 5° in SNB as maxillary protrusion, and less than 85° in SNA and over 5° in SNB as mandibular retrusionn, and less than 85° in SNA and less than 5° in SNB as normal occlusion at 16 years old. The results were as follows.
1) The mean values of the over jet in the maxillary protrusion group were significantly larger than those in the normal occlusion group at ages 6 and 16.
2) The mean values of the over bite in the mandibular retrusion group were significantly larger than those in the normal occlusion group at age 6, which showed a larger tendency to disappear with age. During ages 6 to 16, the mean values of the over bite in the bimaxillary protrusion group showed a smaller tendency compared with the other groups.
3) The mean values of N-ANS and ANS-Me tended to be larger in the mandibular retrusion group at ages 6 to 16, which were significantly smaller than those in the normal occlusion group at ages 9 and 12.
5) The mean values of PNS-ANS in the maxillary protrusion group at each age were not found to show significant differences among the four groups.
6) The mean values of PNS-A in the maxillary protrusion group were significantly larger than in the normal occlusion group at ages 12 and 16, which were not shown at ages 6 and 9.
7) The mean values of G-Me in the four groups were almost the same at ages 6to 16.
8) The mean values of the maxillary contents in the maxillary protrusion group were not larger compared with the other groups, and those of mandibular retrusion group tended to be large among the four groups.

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To clarify the effect that anesthesia or no anesthesia has no facial expression changes in children (their eyelids, eyebrows and forehead), a comparative analysis was made of different age groups during restoration. Altogether 40 children and their parents agreed to cooperate in the experiment: 20 preschool children aged 3 to 6, and 20 school-age children aged 6 to 10. Cavity preparation and plastic filling were performed on the subjects having slightly carious primary molars, with with and without anesthesia. At the same time, facial expression changes in the children at each step in the treatment were noted for a total of 80 cases: 40 for those who received infiltration anesthesia (numb group) and the same 40 when they did not (normal group).
A summary of the results is as follows:
1. Comparison during treatments in the normal group. For all subjects in the three regions of the eyelids, eyebrows and forehead, a significant difference was observed in expression changes during the use of the art-turbine, engine, vacuum suction and the air syringe. The changes during drilling were large but during supplementary treatment they were small. It was the same for all ages.
2. Comparison during treatment in the numb group. For all of the subjects a significant difference was observed in the forehead between drilling and supplementary treatment, and for both age groups in the eyebrow region between turbine and air treatments, although the items of significant difference were fewer than in the normal group.
3. Comparison between the numb and normal groups. Effective control of facial expression changes was obvious in the low score of of the numb group compared with the normal group. The same trend could be observed for both age groups although the control of expression changes in the preschool group was very evident.
4. Comparison of the drilling treatment between those who received infiltration anesthesia and those who did not. The score for those who did not receive anesthesia was much higher than that of those who did in almost all regions of the eyelids, eyebrows and forehead in the preschool children. Changes in the forehead and eyebrow regions for the preschool children were larger at the time of infiltration anesthesia than those of the normal group during the use of the turbine or engine.

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The purpose of this investigation was to examine the awareness of the dental alignment and the occlusion between children and their parents living in the cities of Nagoya and Fukuoka. Four hundred and seven school boys and girls and 404parents answered the questionnaire.
The results were as follows;
1) The subjects were generally aware of anterior characteristics. For example, about 25% of the children and their parents recognized anterior cowding, and about 2% of the children and their parents were aware of anterior crossbite.
2) The majority of the subjects were indifferent to dental alignment and occlusion.
3) Many parents were concerned about their children's dental alignment and occlusion from the point of view of health.
4) Over 90% of the parents answered that dental caries influenced general health, over 80% of the parents answered that occlusion influenced it while over 60%of the parents answered that the dental alignment influenced it.
5) Almost all of the parents knew the words 'alveolar pyorrhoea', 'periodontitis'and 'orthodontics'. Over 70% of the parents knew the word' occlusion'.
From now on, it is very important to inform to society that the dental alignments and the occlusion influence not only on esthetics but also health.

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The change of the angle and the distance of the x-ray projection were examined with the bite-wing technique that is often used in the pediatric clinic.
The results were as follows:
1. With the condition that the position of the object and the angle of the x-ray film were fixed, and the angle of the x-ray projection was changed, the correlation between the original x-ray film and the experimental x-ray film was over 95 % when the angle was in the range of -6° to +4° on the X-axis, and _-4°to +10° on the Y-axis, and _-10° to +14° on the X-axis and -30° to +30°on the Y-axis, for the dry human mandibula and the dry pig mandibula, respectively.
2. With the condition that the angle of the x-ray projection was fixed against the film and the angle of the object was changed, the correlation between the original film and the experimental film was over 95 % when the angle was in the range of 4°- to +6° on the X-axis and -3° to +30 on the Y-axis for the human mandibula, and -12° to +15° on the X-axis and -15° to +15° on the Y-axis for the pig one.
3. A correlation of over 95% between the original film and the experimental film was found when the distance between object and x-ray film was from 0 to 30 mm.

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It should be advised to employ a suitable respiratory monitor during dental treatment of patients with disease affecting the respiratory function. In the present study, the end tidal carbon dioxide (ETCO2), arterial oxygen saturation (SpO2)and respiratory rate (RR) were measured simultaniously from both healthy and medically compromised patients using the 4700 Oxicap® monitor (Ohmeda) and the usefulness of capnometer for the respiratory monitoring during dental treatment was evaluated.
When the respiratory volume (RV) of healthy adults (n=10) was voluntarily reduced, all of them showed a decrease in SpO2 and an increase in ETCO2 without change in RR, indicating a close relationship between RV and SpO2 and ETCO2. Although the fluctuation of ETCO2 became slightly larger than the pretreatment level, neither ETCO2 nor SpO2 showed significant change throughout the dental treatment in healthy children (n=10). On the other hand, SpO2 decreased during local anesthesia and dental treatment in patients with cerebral palsy (CP), suggesting poor ability to recover from hypoventilation which is supposed to be caused by stress. We did not observe an apparent increase in ETCO2 during dental treatment in CP patients. Apnea, which occured spontaneously during dental treatment of patients with CP or Rett syndrome, was detected promptly by the capnometer module in 4700 Oxicap as a disappearance of exhalation in the CO2waveform. The change in the CO2 waveform was followed by changes of ETCO2and SpO2 values which lagged by 20-40 sec.
In the patients with disease affecting the respiratory function, the capnometer appears to be a useful respiratory monitor during dental treatment and the combination of capnometer and pulse oximeter seems to be the most powerful system for respiratory monitoring.

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A physiological, space on the deciduous dentition is useful for the alingment of the parmanent teeth. Even if a spaced deciduous dentition is the forerunner of the permanent teeth, there is some chance of crowding of the permanent teeth. Thus, the relationships among the interdental spaces, mesio-distal crown diameter and dental arch length of the deciduous dentition were investigated using 185dental casts of children in primary dentition. A digital vernier caliper was used to measure the arch length, tooth widths, and contact guages for the interdental spaces.
The results were as follows:
1. In the mesio-distal crown diameter of the deciduous maxillary and mandibular teeth, there were no significances between the right and left teeth.
2. The mesio-distal crown diameters of the deciduous maxillary and mandibular teeth of the boys showed a tendency to be invariably greater than those of the girls.
3. There was a tendency for the mesio-distal crown sizes to decrease as the interdental spaces increased.
4. Especially in the lower arch, as the interdental spaces increased, the length of the dental arch increased.

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Though oral hygiene is the most important item for controling dental caries or periodontal disease, the maintenance of the oral hygiene instrument after use should be paid attention to. Uncleanliness of the toothbrush may cause the growth of many microorganisms and transmit infectious disease.
The purpose of this investigation was to survey the daily procedures of the maintenance of toothbrush and to estimate the amount of bacteria left on bristles after use and rinsing by children.
1. The amount of bacteria adhering to the toothbrush after use and rinsing are 3.5×103-3.7×106 CFU, the average of 4.8×105 CFU.
2. The procedures of rinsing the toothbrush made a difference in the amount of bacteria adhering to the bristles and cleaning with tap water was significantly effective.
3. The maintenance of oral hygiene instruments in households is not sufficient based on the results of questionnaires.
These results suggested the necessity of instruction concerning procedures of maintaining cleanliness or maintenance of the tooth brush.

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The purpose of this study was to investigate the growth history and related matters of the TMJ dysfunction syndrome in comparison with the normal group in junior high school children and high school students in the city of Kagoshima.
The results obtained were as follows:
1) A partial chewing, clenching, restting of one's chin on one's hands, an anamnesis of trauma and family history were significantly more frequent in the TMJ dysfunction syndrome group than in the normal group.
2) In regard to eating foods which need to be chewed well, there was no significant difference between the TMJ dysfunction syndrome group and the normal group based on evaluation of the average amount of masticatory action.
3) Over 50% of the food which was listed in the answers could not be evaluated and how many of the foods were cooked was not explained.
4) The items which were consistent with the results of other reports in the association with the TMJ dysfunction syndrome were a partial chewing, bruxism (grinding, clenching) and an anamnesis of trauma.

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We investigated 1,946 outpatients of Nihon University Dental Hospital Department of Pediatric Dentistry, from 1978 to 1992, who had answered questionnaires on dental health control and we totaled the information in the questionnaires.
We arrived at the following conclusions.
1. With regard to the incidence of each peculiarity in males and females in total, finger sucking was seen most frequently, onychophagia was followed by mouthrespiration, and the incidence of lip biting was the lowest.
2. We divided all of the subjects into two groups to find out the recent tendencies. We compared the incidence of each peculiarity in the first group (1978-1985)with that in the second group (1986-1992). Finger sucking, mouth respiration and onychophagia tended to be seen more frequently in the second group than in the first group.
3. With regard to the duration of the period of finger sucking, the cases lasting up to three years were seen most frequently. As for onychophagia, cases lasting for one or two years were most frequently seen.
4. We examined the starting time and the ending time of the peculiarity. For finger sucking, cases in which the starting time was less than one year old were seen most frequently. There were no cases which began after six years of age. Moreover, cases in which the ending time was at three years of age were seen most frequently. With regard to onychophagia, the cases which began at three years of age were seen most frequently. The peak of the ending time ranged from four years of age to six years of age, and cases in which the ending time was after six years of age gradually decreased in number.
5. There were few connections between finger sucking and the following factors: up-bringing, the life-style or whether the mother worked. When the child lived with the grandparents, finger sucking was not so frequently seen. When the grandparents were taking care of the child chiefly, finger sucking tended to be not so frequently seen as compared to the case when the father was taking care of the child. When the father worked for a company or worked at an educational research organization, finger sucking was more frequently seen in comparison to the case when the father was self-employed or civil servant. When the child was the only child, or the middle child, finger sucking was more frequently seen in comparison to the case when the child was the eldest or the youngest in the family.

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The genetic contribution to the growth change of the craniofacial size and shape of rats was examined with use of cephalometry and the finite element method. The statistical analysis showed such trends as the similarity of the craniofacial size and shape was higher among the F1 offspring, intermediate among the F1 offspring and sire or the F1 offspring and dam, and lower among sire and dam. The similarity of the craniofacial size and shape was higher in accordance with the degree of the genetic correlation. It is, thus, indicated that the genetic effect plays an important role in the growth change of the craniofacial size and shape in rats and that a finite element method was useful to quantify the size and shape of the craniofacial complex.

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The purpose of this study was to investigate the effects of various tooth surface conditioners, primers, bonding agents and liners onthe resin adhesion to the primary dentin.
The labial surfaces of 18 extracted or exfoliated human primary anterior teeth and 186 extracted and frozen bovine mandibular primary incisors were used. Six adhesive treatment groups were prepared: Group 1 (K-etchant, Clearfil Photo Bond: Kuraray Co. ), Group 2 (CA agent, SA Primer, Clearfil Photo Bond, Protect Liner: Kuraray Co. ), Group 3 (10-3 Solution, Superbond Primer, Superbond D Liner: Sunmedical Co. ), Group 4 (Gluma 2000-1, Gluma 2000-2: Bayer Dental Co. ), Group 5 (Scotchbond Multi Purpose Etchant, Scotchbond Multi Purpose Primer, Scotchbond Multi Purpose Adhesive: 3M Co. ), Group 6 (All-Etch, Primer A and B, Dentin/Enamel Bonding Resin: Bisco Inc. ). Composite resins used in this study were Clearfil Photo Anterior (Kuraray Co. ) in Group 1,2-A,2-B,3 and 6-B, Pekafill (Bayer Dental Co. ) in Group 4, Z 100 (3M Co. ) in the Group 5 and Bisfil-M (Bisco Inc. ) in Group 6-A. Waiting time after application of the primer was 10 seconds in Group 2-A and 60 seconds in Group 2-B. Thermal cycling tests thermocycled 10,000 times between water baths maintained at 4°C and 60°C were attempted. The effects of tooth surface conditioners were observed in the SEM. The shear bond strength was tested and the test surfaces of the dentin and the resin specimens were observed in the SEM.
1. The efficacy of the tooth surface conditioners were All-Etch =Gluma 2000-1≥Sctotchbond Multi Purpose Etchant=10-3 solution>K-etchant>CA agent.
2. Dentin-resin adhesion patterns differed among the groups.
3. The groups which showed the significant difference of the bond strengths between the non-thermal cycled group and the thermal cycled group were Group 2-A and Group 2-B. In Group 2-A, the bond strength of the non-thermal cycled group was significantly higher than that of the thermal cycled group and in Group 2-B, the bond strength of the thermal cycled group was significantly higher than that of the non-thermal cycled group.
4. Both in the non-thermal cycled group and the thermal cycled group, the bond strengths of the Group 3(30.67±7.38MPa,25.99±6.41MPa)and the Group 6-B(35.46±11.48MPa,30.77±14.67MPa)showed over 25MPa.

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As in the case of dental caries, the periodontal diseases are influenced by many factors that are interconnected. Although it is difficult to isolate these relative factors from one another, one of the major etiologic factors of periodontal diseases in children is reported to be life customs. The purpose of the present study was to determine the relationship among these distinctive life custom factors and gingivitis in children by using a multivariate analysis method.
The following results were obtained.
1. The relationship between eating habits and gingivitis in elementary school children and junior high school students involved such factors as regular dental check ups (including the guardians and their children). However, the following factors were found in the relationship between eating habits and gingivitis; preference of sweet foods, eating before sleeping and eating irregularly between meals.
2. The following similar factors were found in elementary school children with severe gingivitis; eating before sleeping, eating irregularly between meals, a dislike of firm foods and poor tooth brushing habits. These factors were also considered to increase the severity of gingivitis.
3. On the other hand, the following factors were found in elementary children with dental caries but with only minor gingivitis; eating regularly between meals, not eating a lot of sweet foods and good tooth brushing habits.
4. Among junior high school students, there was no relationship found between severe gingivitis and eating habits. However the following factors were found related to middle stage gingivitis; brief time of mastication, preference of sweet foods and lack of regular dental check ups.
5. On the other hand, junior high school students with minor gingivitis showed a diet of not many sweet foods and eating regularly between meals. Moreover, guardians, children and students who showed elements of health attitudes which were good, also showed tendencies towards good health.

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Oolong tea extract (OTE) containing polymerized polyphenols inhibited insoluble glucan synthesis from sucrose by the glucosyltransferases of mutans streptococci. In this study, we evaluated the difference of the inhibitory effect among the ways of administration of OTE to SPF rats. The administration of OTE compound into the diet and drinking water resulted in significant reductions in caries development in rats infected with Streptococcusso brinus 6715. The administration of OTE compound into either the diet or drinking water also significantly inhibited caries development. Furthermore, rats administered the commercial product of oolong tea as drinking water showed significantly reduced caries development, when compared to the control rats.
These results indicate that the anti-cariogenicity of OTE is not affected by the way of administration and it could be useful as anti-cariogenic food additives.

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The purpose of the present study was to investigate the changes of the electromyographic (EMG) activities of the perioral muscles during sucking periods in infants.
Forty infants (23 males,17 females, mean age: 14.2 wks after birth) were the subjects of the evaluation. EMGs were able to be obtained from 4 perioral muscles such as the unilateral temporalis (TM), masseter (MM), orbicularis oris (OM) and suprahyoid muscles (SM) from the start to the end of feeding. Comparisons were also made between breast feeding (BRF,20 infants) and bottle feeding (BOF,20infants). The evaluation parameters employed were the EMG activities (μV, peak to peak), the frequency of sucking burst (%) presented in the EMG and the ratio of each muscle activity (%) to the total muscle activity found in the first consecutive sucking EMG bursts. Those bursts were further subdivided into three periods according to the sucking time such as the early, middle and late periods.
The following results were obtained:
1) Each muscle activity varied according to the subject, muscles and sucking period. The muscle activities of the four muscles decreased with the sucking time. The SM was the most active, followed by the OM, MM and TM. Total muscle activity also showed differences among the subjects and the sucking period.
2) The BRF showed higher EMG activity than BOF in the MM, OM, SM and the total muscle activity.
3) The ratio of each muscle activity to the total activity was 9.5% in the TM,12.0% in the MM,28.0% in the OM,50.5% in the SM in the BRF infants, and 11.0%,11.5%,27.5% and 49.0% in the BOF infants, respectively. There were no differences in the ratio in each muscle between the BRF and BOF group, and in the sucking periods.
4) The frequencies of the EMG bursts for sucking showed the highest in the OM and SM, and followed by the MM and TM, and it declined with the passing of time in the MM and TM, but not changed in the OM and SM. It may be concluded that the SM and OM function mainly during sucking movement both in breast and bottle feeding infants, and the muscle activities of each muscle decrease with sucking time, while the ratio of each muscle activity to total muscle activity does not vary.

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We investigated the influence of the hardness of the chewing gum bolus on the electromyograms (EMGs) of the masticatory muscles in both children and adults with normal occlusion.
The subjects were divided into three groups, IIA, IIIA and IVA, according to Hellman's dental age classification. The gum was classified into soft, medium and hard types, according to hardness of the gum. All of the subjects were instructed to chew the gum on the right molars. Bipolar surface EMGs were recorded bilaterally from the masseter muscle and the temporal muscles.
The harder gum induced higher integrated values of the jaw closing muscle EMGs in order of the dental age. However, the hard gum did not the increase cycle times of the EMGs in the groups except in group IIA.
This suggest that the proprioceptive feedback is involved in the chewing of hard foods rather than the generation of chewing rhythm in the process of human growth and development.

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Calcium hydroxide has been used widely as a vital pulpotomy agent for primary and immature permanent teeth in pediatric dentistry. When this paste is placed over the amputated pulp, it is known to promote healing by formation of the dentin bridge. In normal clinical application, however, it is necessary to mix it with calcium hydroxide powder and sterlized water and to prepare sterlized instruments. This procedure is complicated for both the operator and the assistant. Therefore, ready-made calcium hydroxide paste, or a one-paste type, was newly designed.
The purpose of present study was to investigate the formation of the dentin barrier in the immature permanent teeth of young dogs with the one-paste type calcium hydroxide paste. The dogs were sacrificed at 1 month after the pulpotomy. The serial sections were obtained and observed histopathologically. The formation of the dentin bridge was observed, and the findings were the same as those of only the calcium hydroxide used. There were also no findings of damaged pulp cell under the dentin bridge. This result suggests that the one-paste type calcium hydroxide paste is useful for pulpotomy.

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The degree of tooth formation was studied quantitatively using 1101 orthopantomograms (533 males and 568 females) obtained from Japanese children aged 2 to 15 in the pediatric clinic of Fukuoka Dental College. The assessment was based on the tooth formation stages by Moorrees, et al. slightly modified by the authors. They were divided into 14 stages for permanent first and third molars.
Each stage consisted of points ranging from 1 to 14.
The following results were obtained.
1. The permanent first and third molars on one side developed at the same rate as its counterpart on the other side regardless of sex or arch differences.
2. The tooth germ of the upper third molar was found first at age 6 and the lower third molar at age 5.
3. The occurrence time of the tooth germ of third molar was almost the same as the root-apex formation of the first molar. The occurrence of the right and left sides was 76%.
We concluded that the root formation of the permanent first molar can serve as an index of the tooth germ formation of the third molar, and also this finding contributes to the radiation reduction in children.

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The purpose of this study was to discover the growth of the tooth hard tissue after eruption. The subjects consisted of 42 children with normal occlusion (6,10,13 years old) who came as outpaitents to the Kyushu Dental College Hospital for examination.
The lower first permanent molars was observed with use of the dental film. The photodensitometry method was used to measure the degree of calcification in the hard tissue of the tooth crown.
The results were as follows.
1. The average of the degree of calcification for boys was 4.02±0.38 mmAl for age 6,4.92±0.51 mmAl for age 10, and 5.73±0.76 mmAl for age 13, and for girls was 4.18±0.41 mmAl for age 6, and 5.08±0.49 mmAl for age 10,5.67±0.75 mmal for age 13.
2. The t-test of the sexes and the ages showed no significant difference between boys and girls from age 6 to age 13. In comparison the calcification degree by age, between those aged 6 and 10, those aged 10 showed significantly greater values(p<0.01)than. those aged 6; between those aged 6 and 13, those aged 13 showed significantly greater values (p<0.01)than those aged 6 and between those aged 10 and 13, the aged 13 showed significantly greater values(p<0.05)than those aged 10.
3. The coefficient of the correlation between age and the calcification degree was r=0.712. The expression of the regession line, with age on the X-axis and the calcification degree on the Y-axis, was Y=0.26X+2.55.
4. As basic examination items for reproducibility of measurement, coefficients of variation were obtained using the skulls of 6-year-old, Indian children for (i) variation based on the exposure dose of X-ray irradiation. The value for (i) was 3.04% and for (ii) was 3.25% and it was confirmed that variations in measurement were small.

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Bilateral temporomandibular joints of 33 patients with temporomandibular joint dysfunction syndrome (TMJDS) and 12 normal people were examined using fuji computed radiography (FCR) and magnetic resonance imaging (MRI). Then, the author evaluated the relationship between the signs of TMJDS and the state of the internal temporomandibular joint.
Temporomandibular joints of the TMJDS patients were separated into four groups based on MRI findings. Group I: No anterior disc displacement (ADD)Group II: ADD with reduction Group IIIa: ADD without reduction and maximum opening width is over 32 mm Group IIIb: ADD without reduction and maximum opening width is under 24 mm.
The following results were obtained:
1. The frequency of occurrence of limitation was significantly high in the group IIIa and IIIb patients. The locus area of condyle and disc in the group IIIa and IIIb was found to be smaller than that in the normal group based on the MRI findings.
2. The frequency of occurrence of TMJ pain was significantly high in the group IIIa and IIIb. Physiological compression of disc with opening was recognized in the group IIIa and IIIb as observed from the MRI findings.
3. The frequency of occurrence of TMJ sounds was highest in the group II.
4. The period from the initial attack of limitation and visiting our hospital for the group IIIa patients was significantly long compared with the group IIIb patients. The condyle position in fossa was much lower vertically in the group IIIa as compared with the group IIIb based on the FCR findings. The frequency of the mesio-lateral disc location was significantly low and the area of disc forward movement increased in the group IIIa compared with the group IIIb as observed from the MRI findings.
5. The condyle position in fossa of the normal group was in the center area horizontally. It was significantly backward in the group I, II, IIIa and IIIb as compared with the normal group. The condyle position in fossa of the normal group was in the lower area vertically. It was much higher in the group II and IIIb compared with the normal group.
6. Based on the quantitative evaluation in the normal group, the locus area of condyle and disc on mandibular opening was found to be small from the intercuspal position to the 24 mm opening position and it increased forward in the bigger opening position.

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Electromyographic studies were performed to find out the relationship between the development of the orthognatic systems in children and the change of the electromyogram patterns of their masticatory muscles. The correlations between the sizes of their dental arch and the electromyographic parameters were also investigated. The main findings were as follows.
1. The integrated values of the electromyograms of gum-chewing and maximum biting showed that the occlusal development in children corresponded to the change of the occlusal function from the TA-type mastication to the M-type mastication.
2. Powerspectral analyses of the electromyograms of gum-chewing showed that the powerspectrums shift of lower frequencies occurs when they developed.
3. The integrated values of the electromyograms of maximum biting showed that the M-type was more easily fatigued compared to the TA-type.
4. Though some factors such as the sizes of the dental arches had some correlation with the integrated values of the electromyogram, we were not able to find out evidence enough to account for their relationship.

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Rieger's Syndrome is an autosomal-dominant heritable disorder with triad of hypoplasia of the anterior iris stroma, bridging angle of the iris strands and posterior embryotoxon. Other various clinical findings were manifested due to abnormal development of the mesodermal tissue. The present findings of a sixyearold boy affected with Rieger's Syndrome were as follows.
1. Three irregular pupilla, cloudy cornea and auricular septal defects.
2. Low body height and delay of bone age.
3. Microdontia of the lateral upper incisors and delay of calcification of the upper second premolars
.4. Hypoplasia of the maxilla and anterior crossbite.
5. Occlusal correction of the anterior crossbite using a Frankel type III unit.

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The acute type of idiopathic thrombocytopenic purpura (ITP) occurs most often in childhood between 2 and 6 years of age with equal sex distribution. At the onset, severe hemorrhage occasionally begins in the extensive areas of the gingiva. Therefore strong local hemostasis is of importance even in the relevant sites.
A 5-year old girl with an excessive amount of gingival bleeding was referred to the Chiba Children's Hospital. At the first examination, persisting hemorrhage was seen from the gingival cuffs around the teeth. The laboratory data were as follows; white blood cell counts,7.7×103/μl; red blood cell counts,392×104/μl; platelet counts,0.7×104/μl; pro-thrombin time,12.2sec; activated partial thromboplastin time,27.8sec; plateiet associated immunoglobulin G,265.6μg/celi; megakaryocyte,94/μl. Acute ITP was suspected from the patient's clinical manifestations and the laboratory findings obtained.
Immediately after hospitalization, dental splints were employed on the dentitions of both jaws for the purpose of compression hemostasis of the gingival bleeding. Subsequently high-doses of intravenous gammaglobulin were administered at a dose of 0.7g/kg/body-weight /day for 3 days. Four days after, as the platelet counts rose to 5.1×104/μl, the splints was removed. The platelet counts were achieved to26.5×104/μl after one month and maintained in a normal range in the following days. Acute ITP was confirmed even on the final diagnosis.
In summary, throughout the clinical course, no platelet infusion was performed to prevent the potential danger of viral implantation. In this case, dental splints and gammaglobulin were enough to relieve the patients of the acute ITP with bleeding.

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The ambulatory surgery center of the University California San Francisco (UCSF) was established in 1987. Dental procedures are one of the common cases in the surgery center. The purpose of this study was to investigate the characteristics of out-patients and dental treatment under general anesthesia of Pediatric Dentistry at the UCSF Surgery Center.
One hundred and fifty-six outpatients who received dental treatment under general anesthesia by a pedodontist at the UCSF Surgery Center from May 1990to August 1992 are included in this study. The data were obtained from the patient's clinical and operative record cards. The data of patients were distributed into three groups. The first group was composed of normal healthy children (Normal group), the second group of the patients with major medical problems (Medical Problem group), and the third group of mentally handicapped patients (Handicapped group).
The results were as follows; The largest size group was the normal group including 97 patients(62.2%), and the next size group was the handicapped group (37 patients,23.7%). The smallest size group was the medical problem group including 22 patients(14.1%). The youngest average age among the three groups was 3.3 years (±1.2 years) in normal group. The average age of the medical problem group was 5.0 years (±2.4 years) and that of the handicapped group was 10.4 years (±7.5 years).
The medical problem group had major problems such as heart disease(7patients,31.8%), hemophilia(6 patients,27.3%) and leukemia(4 patients,18.2%). The handicapped group included mental retardation, cerebral palsy and autistic patients. Ten patients(27.0%) of the handicapped group suffered from major medical problems. The problems was heart disease.
The average number of the total treated teeth per person was 10.3 in the normal group,9.5 in the medical problem group and 7.6 in the handicapped group. The ratio of the restorative teeth of the normal and medical problem groups was higher than that of the handicapped group. While the ratio of tooth extraction of the handicapped group was higher than that of the normal and medical problem groups, in some patients of the handicapped group, ambulatory general anesthesia was applied for deep scaling(11 cases) and/or gingiver ectomy(8 cases) as the main procedure.
Approximately 78% of the cases finished all of the procedure in the operating room within 2 hours, and moved to the recovery room. All cases were able to return to their homes with stable condition and did not suffer from any major adverse effects at home.
The authors are very grateful to Dr. Martin S. Bogetz, M. D. for allowing us to use statistical data from the U. C. S. F. Surgery Center.

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A clinicalo bservationo f 520 traumaticallyi njured primary teeth of 308 children who had visited the Pedodontic Clinic of Niigata University Dental Hospital from September 1979 to March 1994 was conducted. Among these cases,65permanentt eeth of 38 childrenw hosep ermanents uccessorhs ad erupted were in-, vestigatedt o studyt he effecto f traumatici njuriest o the primary teeth on their permanent successors.
The results are summarized as follows:
1) Traumatic injuries to the primary teeth occured most frequently at 1 and 2years of age. Boys were injured more often than girls in a ratio of 1.75: 1.
2) Injuries to the upper central incisors accounted for 71.9%, and the number of injured teeth per child was mostly a range of two. The main cause for trauma was falling down, and 24.7% of the patients visited our clinic on the day after the accident.
3) Luxation was found in 182 teeth, loosening in 160 teeth, and tooth fracture in 145 teeth. The most common treatment was observation, with fixation and extraction following.
4) Developmental disturbances were found in 15.4% of the permanent successors of the injured primary teeth.
5) Based on age at the time of injury, disturbances of crown formation were observed in the young-age group, and disturbances of root formation and eruption were observed in the high-age group.
6) Follow-up observations must be conducted until the permanent successor erupts.

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A clinical observation on 370 traumatized permanent teeth of 202 children was conducted from September 1979 to March 1994 in the Pedodontic Department, Niigata University. The prognoses were surveyed for 49 teeth.
The results are summarized as follows:
1) The highest incidence was found in children 8 years of age, with 7 and 9 years following in order.
2) Boys were more traumatized than girls with a ratio of about 2: 1.
3) The upper central incisors were most frequently affected.
4) The number of traumatized teeth per child was a range of two in over 80%of the cases.
5) The main causes for trauma were falling down, with colliding and dropping next.
6) Loosening was the most frequent, and crown-fracture without pulp exposure was next.
7) Fracture of the teeth was less commonly found in children aged under 7 year than in those over 8 years old.
8) Long-term observations of traumatically injured immature permanent teeth are necessary until completion of permanent dentition at least.

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Oculo-dento-digital syndrome is an autosomal dominant disorder with a small orbita, hypoplasia of the nasal wing and digital anomaly of the hands and feet due to ectodermal dysplasia. It is one of the most interesting congenital diseases in dentistry because of various clinical manifestations of hypoplasia of the tooth and jaw. The present findings of a four-year-old girl affected with Oculo-dento-digital syndrome were as follows.
1. Rough and short hair.
2. Microphthalmus, ocular hypotelorism and repaired bilateral fusion of the eye lids.
3. Repaired bilateral syndactyly of the forth and fifth fingers in the hand.
4. Morphological anomaly of the condyle and cronoid process.
5. Hypoplasia of the teeth and narrowed pulpal cavity.
6. Abnormal horizontal absorption of the alveolar bone.7. Congenital missing of the right second premolars.

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We encountered two cases (mother, son) diagnosed as partial anodontia without congenital ectodermal dysplasia.
The findings were as follows,
1) Case 1: A 7-year-old male with_??_which were congenitally absent. Case 2: A 32-year-old female with_??_which were congenitally absent.
2) In Case 1, abnormalies on the mesiodistal diameters of the crown were found in the upper and lower deciduous canines, and the second deciduous mandibular molar. In the future, the underdeveloped growth of the maxilla may result in the growth of mandibular prognathism according to roentgen cephalometric analysis. For improvement of this, a chin cap for the mandibular was applied. For improvement of the midline diastema, a direct bonding system was applied.
3) In Case 2, the atrophy of the alveolar ridge was found. A partial denture was used in her oral cavity.
Based on the observation, it was thought that this disease was caused by the presence of a dominant gene. In case 1, it was also considered that the disease may be hastened more and more because of a few congenitally missing teeth in the father. In Case 2, she was not healthy when she was born. It was also considered that may hasten her disease even more.

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Eruption Sequestrum generally produces no symptoms, while it shows discomfort or pain during mastication in some cases, and then it will spontaneously fall off. We described the clinical and histopathological findings of eruption sequestrum appearing in the lower first molar region of 2 children, both 6-year-old boys. The patients complained of indefinite discomfort. Clinical examination showed fibrous binding of a part of a small hard tissue fragment to the gingiva. Histopathological examination of the small hard tissue revealed that osteocytes had disappeared from the bone lacunae, showing sequestrum. On the surface of the sequestrum, bacterial aggregation had been formed. Slight inflammation was observed in the gingiva around the sequestrum. Which seemed to be caused by difficulty in cleaning of the area of the fragment.

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