The purpose of the study was to investigate preliminarily the accuracy of the values for the sucking cycle time by using the integration curve of the EMG from perioral muscles and comparing with the values measured by suckgraph as the control.
Nine babies, with a mean age 13.8 weeks, were used in the observation. Electromyograms from the temporalis, masseter, orbicularis oris and the suprahyoid muscles were obtained unilaterally and the suckgraph was also recorded during sucking of 10% glucose solution. The sucking cycle time was measured by using the suckgraph at first as the control, then the sucking cycle time was also measured by the mean integration curve of the EMGs on a computer.
The following results were obtained;
1 The EMG activity trend and coordination of the four muscles in a sucking cycle could be observed clearly by using the mean integration curve of EMG.
2 The sucking cycle times obtained from the suckgraph and the integration curve of EMG were 647.8±148.8 ms and 653.3±128.5 ms, respectively. There was no significant difference between two measurements.
3 Any differences in the coefficient variation for the mean values both within a subject and among subjects were recognized.
These results suggest that it would become possible to measure the cycle time accurately and to observe the coordination of the four muscle activities by using the mean integration curve of EMG without the suckgraph.

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In this study, to evaluate the state of the gingiva in immatured permanent teeth in terms of microcirculation in the peripheral blood vessels, we measured blood flow in the gingiva using a laser flowmeter. The subjects were 147 children aged 6-14. They were classified into 3 age groups: Group I aged 6-7, II aged 8-9, and III aged 10-14. The evaluated teeth were the central incisor and first molar on the right side of the maxilla and those on the left side of the mandible. The measurement sites were the mesial, middle, and distal areas of the gingiva on the labial (buccal) side of each tooth. The state of the gingiva was macroscopically evaluated using the gingival index (GI) by Lbe and Silness.
The blood flow according to the GI was subsequently obtained in both males and females as a group. The following results were obtained: 1) No definite association was observed between blood flow and gingivitis.2) The blood flow was significantly higher at the distal region of the gingiva than in the mesial region of the maxillary central incisor and first molar, irrespective of the age groups or GI.3) The gingival blood flow in the first molar was about 2 times higher than that in the central incisor at each site of measurement.4) In the mesial region of the gingiva of both the central incisor and first molar, the blood flow was higher in the mandible than in the maxilla.5) The blood flow in the middle and distal areas of the maxillary and mandibular first molars was lower in Group III, and that in the distal region of gingiva of the mandibular central incisor was lower in Group I, more than in the other age groups. These results suggest that wound healing and tissue regeneration appear to be active at the distal area of the molars in younger children.

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Systemic diseases of children differ according to their living environment and dietary habits. Also, as systemic disorders are closely related to the state of the oral cavity of children and their responses to dental treatment, we investigated the state of systemic diseases. The subjects were 1298 children who were treated at the outpatient clinic of the Department of Dentistry, Iwate Medical University.
Inquiry sheets at the initial examination, health records, and records of initial examinations based on the inquiry were used as reference material. The past history to the present illness of the patients was investigated. The following results were obtained:
1) The morbidity rates for various diseases were 57% for viral infection and 38 % for allergic diseases.
2) Viral infection was observed frequently in those aged less 6 years, and varicella accounted for a particularly high percentage.
3) Children aged 0-3 years often contracted bacterial infections and pneumonia accounted for 51.4%of all bacterial diseases.
4) An allergy was observed most frequently in those aged 3-6 years. More than half of the patients with allergy had atopic dermatitis and eczema.
5) Atopic dermatitis alone was observed in 78% of the patients with atopic dermatitis, but the incidence decreased with age.
6) Asthma, food allergy, and drug allergy were often complicated by other allergies and increased with age.
7) Six of the 9 patients who presented allergic symptoms after dental treatment had a history of atopic dermatitis.
In conclusion, most children have various systemic diseases in the period of odontogenesis, and allergic diseases appear in more diverse forms as they grow older. Examining the medical history is considered necessary, before dental treatment is given to children.

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Recently it has been recognized that diet in childhood influences not only the immediate health of children but also may have an impact in a positive or negative manner on the future adult health status of children. We should be encouraged to understand the present status of the diets of children, and introduce early the importance of the optimal diets early in children.
Our objectives were to assess trends in food preferences.2584 Japanese school children aged 9 to 12 years in Kitakyushu City were investigated through a questionnaire which contained the question about a one-sided diet. The following conclusions were obtained.
1) Most kinds of vegetables were disliked by large percentages of children. This tendency in older children was more significant than in those who were younger.
2) Generally children preferred animal foods, especially meat, to vegetable foods, and both yogurt and fruits were the most favorite foods of all.
3) The number of children who liked carrots, fish, bread, or instant Chinese noodles decreased significantly between the third grade and the sixth grade.
4) There were no statistical differences in the trends in food preferences between boys and girls.
5) Approximately 15% of the children in each grade were likely to be on one-sideddiets, and this rate was stable in spite of ages.
6) The results documented in this article showed various problems concerning the diet of children. Some of them for older children were more significant than for those who were younger and others did not improve as the age increased. The style of food preferences for each grade was also quite similar, and this suggested the importance of “Education for both nutrition and self-concept of the chiidren toward optimal diets” at a much younger age.

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The purpose of the present study was to examine both the effect of prophylactic treatment of dens evaginatus with composite resin and the prognosis of canal treatment of immature permanent teeth with fractured dens evaginatus.
Forty one patients (22 M,19 F, average age 12.5 y) with 94 teeth with dens evaginatus were examined longitudinally, The results are summarized as follows:
1. The developmental anomaly was found mainly in mandibular premolars. Of 94 teeth,43 were mandibular second premolars (45.7%), and 28 were mandibular first premolars (28.7%). The ratio of affected lower to upper premolars was nearly 4: 1. The mean number of dens evaginatus per patient was 2.3 teeth.
2. The mean sizes of the tubercle were 2.31 mm (mesial-distal), and 2.04 mm (buccal-lingual) in the mandibular second premolars.
3. Only one of 53 teeth with dens evaginntus which had been reinforced with composite resin fractured during the investigation.
4. By fracturing the dens evaginatus,18 immature permanent premolars became devital. These teeth were administered endodontic therapy with Vitapex® to promote apical development. In 11 of these teeth, closure of the apical root canal by hard tissue formation occurred, with 9 of them showing root development.

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The purpose of this study was to investigate the validity of the Oral Rating Index (ORI; + 2 - -2) as an index to assess periodontal status in junior high school students. The survey was conducted on 357 junior high school students living in Hiroshima, Japan. The results are summarized as follows.
1. The ORI had significantly negative relations to the gingival index (Loe and Silness), plaque index (Silness and Loe), probing depth and bleeding index (p< 0.001, p< 0.001, p< 0.001 and p< 0.001, respectively).
2. With the use of the ORI, the mean score of girls was statistically higher than that of boys (p< 0.001). The mean score of the ORI of students decreased in proportion to their grade, indicating that their periodontal status tended to be worse in proportion to their grade.
3. The ORI provided logical groupings of students and simplified the analysis of the data collected. The examination was less time-consuming than the normal periodontal examination and still provided information that would enable the dentist to determine practical oral health instruction.
In conclusion, the ORI was found to be an useful index to screen the periodontal status in junior high school students as well as in other field groups.

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It is postulated that mothers have some effect on dentists during the treatment of their children. The purpose of this study was to develop a psychological stress response scale for dentists during the treatment of children in order to measure the above mentioned multifarious aspects of psychological stress responses. The subjects were dentists from the Department of Pediatric Dentistry and the Hiroshima University School of Dentistry (22 total). We developed the Psychological Stress Response Scale by using a questionnaire. The reliability of the scale could be seen by its internal consistency and the stability. Its validity was shown by a correlation coefficient and t-test. The t-test was examined by analyzing the contrast of the stress scores during the dental treatment among the two groups of high and low psychological stress of daily life.
The findings were as follows:
1. We analyzed our questionnaire and found the following seven types of stress effecting mothers: overly-demanding mothers, communication deficient mothers, overly strict or nervous mothers, overprotective mothers, overly-concerned mothers, talkative mothers, overly-emotional mothers.
2. The high reliability of this questionnaire was clearly evidenced by its internal consistency and the stability.
3. The validity of the development of the Psychological Stress Response Scale was confirmed by the finding that high stress level groups had high psychological stress scores in dental treatment for children and low stress level groups had low psychological stress scores in dental treatment for children.
These results suggest that this questionnaire was effective for measuring the degree of a mother's effect on a dentist during treatment of their children.

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Recently it has been recognized that diet in childhood not only influences the immediate health of children but also may have an impact in a positive or negative manner on the future adult health status of children. We should be encouraged to understand the present status of diets of children, and introduce early the importance of the optimal diets in children.
Our objectives were to assess trends in food preferences for the daily menu.2584 Japanese school chiidren aged 9 to 12 years in Kitakyushu City Were investigated by questionnaire. The fo 11 owing conc 1 usions were obtaine
1) Both stapie food and main dishes were liked significantly by children.
2) Generally children disliked the dishes which were made with vegetables, fish, or based on sour taste.
3) The preferences of food was supposed to be under the great influence of taste.
4) For the individual ratios of those who answered “liked” for practically all tradition Japanese dishes, there was a significant difference.
5) The ratios of those who answered they had no information about each dish decreased from the third grade to the sixth grade.

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Trauma to primary incisors occurs during childhood both of the maxilla and mandible. Damage to the primary dentition may possibly be related to the degree of primary root resorption. The finite element method was used in this study to assesss stress and displacement during trauma to the mandibular primary central incisors, alveolar bone, mandibular bone and successive permanent tooth germs for different degrees of root resorption.
The following results were obtained:
1. Trauma to mandibular primary central incisors in the period from no primary root resorption to one-third root resorption was noted to cause luxation of the primary teeth and injury to the crowns of the successive permanent teeth.
2. Trauma in the period from one-third root resorption to full root resorption may possibly cause losed of primary teeth along with alveolar bone fracture, injury to the root and hinder the emergence of the permanent teeth.
The development and emergence of the permanent teeth should be carefully observed following trauma to primary incisors.

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Eighty children aged from six to nine years-old who visited our Pedodontics Department on an outpatient basis served as subjects. The effectiveness of finish brushing performed by parents using the electric toothbrush was investigated. According to the eruption stage classification system established by Araki, the first permanent molars were classified with respect to the degree of eruption, and the differences between the effectiveness of brushing by the children themselves and that of finish brushing by parents were compared and analyzed in each stage using three types of electric toothbrush. In addition, a survey was conducted on finish brushing and the usability and operability of electric toothbrushes.
The following results were obtained.
1. When children brushed their teeth by themselves: Compared to manual brushing, the effectiveness of brushing was higher with reverse and combination type toothbrushes in stage 1 teeth, and with all types of electric toothbrush in stage 2 and 3 teeth. Significant differences were also found between manual brushing and reverse or combination types in stage 1 teeth, and between manual brushing and all types of electric toothbrushes in stages 2 and 3 teeth.
2. When finish brushing was performed by parents: Compared to first permanent molars with a low degree of eruption that were brushed by the children by themselves, higher cleaning effects were obtained with all types of electric toothbrushes, and significant differences were found between manual brushing and vibration or combination types in stage 1 teeth.

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The purpose of this research was to analyze the problems of the diagnosis of the cleft lip and palate (CLP) using the ultrasound before delivery and information CLP of the babies to their parents and to discuss the network betweent he obstetriciana nd the rehabilitationte am and the system of support the babies with CLP as well as their parents. We sent questionaires to obstetricians in Fukuoka, Yamaguchi, Ooita, Saga prefectures concerning the diagnosis of CLP using the ultrasound and analyze our cases from the Handicap Center in Kitakyushu City. We obtained the following results.
1. We gave the questionairet o 530 obstetriciansa, nd 257 filled the questionaire. The ratio of return was 52%.
2.215 obstetricians (83.7%) encountered delivery of babies with CLP.
3.82 of all of the obstetrician (38.1%) were familiar with the Hotz plate and 17 had used the Hotz plate before. The obstetricians had discovered and diagnosed CLP of the fetus using the ultrasound in the 18 th week of gestation at the earliest and most cases were diagnosed about from the 30 th to the 32 th week of gestation.
4. After the diagnosis,40 obstetricians (32.5%) informed the parents at pre delivery about CLP and 68 (55.3%) informed after delivery and 15 (12.2%) were case by case.40 obstetricians who informed CLP before delivery,28 (70%) informed just at the time CLP was diagnosed and 6 (15%)informed at just delivery.
5. Factors that influenced the decision whether the obstetrician informed before delivery or not were the charactero f the mother 133 (27.8%) and the broadmindednesos f the father 123 (25.7%), as well as the cooperation of the parents 109 (22.8%).
6. There were no relationshipsb etweent he negative reactiona t the time when parents were informed of CLP and the type of CLP, composition of the family members and the presence any other child 1098 with congenital anomalies.
7. Of the cases that have gone to the Handicap Center in Kitakyushu City,12 cases were diagnosed and informed of CLP before delivery, and in about 9 cases we obtained the answeres to the questions.12 parent answered when informed of CLP of their baby, that if there were any explanations of the supporting system after delivery, the information was better before delivery.4 answered it was best before delivery under any condition. In particular,3 of 7 mothers chosed information before delivery regardless of any condition.

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The purpose of this research was to analyze the results of questionaire to the parents of babyies with the cleft lip and palate (CLP) about our early support system in Kitakyushu City.
We obtained the following results about the effects and the problem of early support system and peer counseling.
1. We gave the questionaire to 144 families, and 103 families filled the questionaire. The ratio of return was 71.5%. They included 94 parents and one of the parents 6 (mothers 4, fathers 2), parent and grand mothers 3.
2. Most parents appreciated the explanations about the plastic surgery and the development and nursery just after delivery, and the early support system.
3. The useful explanations in family counseling were about the plastic surgery, the development of speech, the improvment of feeding and the speech therapy.
4. The lack of explanation in family counseling were about the cause and the heredity of CLP. This was remarkable in mothers.
5. The sooner the family counseling is the better it is for both parents and the later, the more family counseling is not enough. At every counseling time, mothers more than fathers said the counseling was delayed.6.8% of the parents obtained the cooperation of the other member of family, but small number of mothers were isolated in their home. More mothers than fathers couldn't adapt in their community.
6.29 fathers and 34 mothers said there was no support from the docter and the nurse until the early support started.
7. Peer counseling cases were 19, bilateral cleft lip and palate 3, unilateral 8, soft and hard cleft palate and soft cleft palate 6, cleft lip 2 (until 1995, december).
8. Many mothers estimated the peer counseling.
9. From above results, network include the peer counseling was necessary for mothers who can't adapt in their home and community.

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The aim of the present study was to investigate the stress responses during dental procedures in adults and children. Dental school students and patients of the Pediatric Dental Clinic, Okayama University Dental School were subjects and were divided into two groups. Study 1 consisted of 80 dental school students (64 men and 16 women). Study 2 consisted of 32 three-to-five-year old patients (17 boys and 15 girls). The changes of nasal skin temperature using thermography during dental procedures in adults and children were evaluated and results are summarized as follows: A high proportion of the adults (90.8%) and children (81.3% on the first and second visits,59.1% on the third visit)showed significant differences between the mean temperature while waiting and during anesthesia.
Of those who showed significant differences, there were the decreased (waiting›anesthesia) and the increased patterns (waiting‹anesthesia). The proportion of the decreased pattern (88.4%) was larger than that of the increased pattern (11.6%) in adults. On the other hand, in children the proportion of the increased pattern (69.2%,61.5% and 76.9%, respectively) was larger than the decreased pattern in each visit. The results of this study indicate that the physiological responses of stress could have the difference between adults and children. This might be due to the emotional development and learning effects concerning with the cognition of being anesthetized.

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The usefulness of thermography to one method in the diagnosis of the temporomandibular joint dysfunction (TMD) was evaluated in this study. Thirty-six subjects were divided into three groups: the control group without TMD, a TMD group with unilateral joint sound and a TMD group with unilateral joint pain. Each group consisted of twelve subjects The skin surface temperature on the temporal (TA), masseter (M), sternocleidomastoid muscles and the temporomandibular joint (TMJ) were measured by the thermographic technique at the rest position of the mandible and the period of chewing. The subjects were also examined for mandibular movement and an electromyography. In addition, the blood flow in the TMJ was observed by using a magnetic resonance imaging (MRI). The results were as follows; 1. In the control group, the difference between right and left skin surface temperature at the rest position of mandible was not significantly recognized, in comparison with those of the joint sound group and the joint pain group.2. In the control group, the difference between right and left skin surface temperature at the rest position of mandible by the existence of habitual chewing did not show any significant difference in the TA and M. In the joint sound group and the joint pain group, there was no significant difference between the region of signs and habitual chewing side.3. There was no significant difference between skin surface temperature on the TMJ and the quantity of the blood flow in the interior TMJ using MRI.4. The temperature peak in the region of M during chewing was significantly lower in that of the joint pain group than that of the control group. Therefore, the temperature peak in the region of M during chewing might be useful as a diagnostic method of TMD.5. The coincidence of time until the right and left temperature reached a maximum temperature was not significantly lower in those of the joint sound group and the joint pain group than that of the control group. Furthermore, the time from the start of chewing to the temperature peak was significantly longer in the symptomatic region in the joint pain group than that in the control group. These results suggest that the coincidence of time until the right and left temperature reached a maximum temperature and the time from the start of chewing to the temperature peak might be useful to diagnose TMD.

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Ninety-two subjects,37 males and 55 females with completed permanent dentition were divided into normal and crowded dentition groups. With models of the deciduous dentitions, crown width, dental arch width, length and height, basal arch width and length were measured and with the models of the deciduous and permanent dentitions correlation coefficients between the deciduous teeth and permanent successors was analyzed.
The results were:
1. As to crown width of deciduous teeth, the values of the crowded dentition group of the males was a little larger than the normal dentition group. The difference between the normal and crowded dentition groups of the females was larger than that of the males. The values of the crowded dentition group were significantly larger than those of the normal dentition in all kinds of teeth of the upper jaw and in the deciduous central incisor and lateral incisor of the lower jaw.
2. As to dental arch width, the values of the crowded dentition group of the males were significantly smaller than those of the normal dentitions in the measuring position of D-D and E-E in the upper and lower jaws. No significant difference was found between the values of the normal and crowded dentition groups of the females. Their values were close to those reported by the Japanese Society of Pediatric Dentistry.
3. As to dental arch length, the values of the normal and crowded groups of both the males and females were approximately the same.
4. As to basal arch width, the values of the crowded dentition groups of the males was smaller than those of the normal dentition in the measuring position of d-d and e-e in the upper and lower jaws. No significant difference was found however between them.
5. As to basal arch length, the values of the normal dentition group of the males were significantly smaller than those of the crowded dentition in the measuring position of B-M2 in the lower jaw.
No significant difference was found however between those of the males and females in the other position.
The dental arch width of the males with deciduous dentition and crown width of the females with deciduous dentition seemed to be factors in forming the normalor crowded permanent dentition.

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This study investigated the changes of the sedative effect and plasma concentration of midazolam, and the status of the recovery of the walking function, and the influence on blood pressure, heart rate, respiratory rate and oxygen saturation (SPO₂) after sublingual administration of midazolam (0.2 mg/kg). The subjects were 8 healthy adult volunteers aged from 19 to 25.
The highest average plasma concentration of midazolam was 71.7 ng/ml at 30 minutes after administration. The initial sedative effect appeared within 10 minutes after administration. A suitable level of sedation was attained at 25 minutes after administration, and that continued until 60 minutes after administration. All of the cases were able to react normally to verbal stimulus and walk normally by 150 minutes after administration.
Blood pressure and oxygen saturation (SPO₂) after administration tended to decrease below the control levels (previous to administration). All of these changes were within normal limits. Heart rate and respiratory rate showed no significant changes, compared to the control levels. No major adverse effects appeared during the experimental period. We believe that the decreases in blood pressure and SPO₂ were due to the sedative effects of midazolam and this technique is suitable for safety conscious sedation.

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We examined the effect of Bodysonic in order to find its relaxation effectiveness on the dentist after treating patients. We used a frequency analyzer of the electro-encepharogram (EEG) “IBVA” to judge the relaxation effects. This equipment can analyze the biolar lead of EEG from the frontal pole and also the oculer movement.
We conducted analaysis of EEG and the oculer movement record of the treatment time on children (Treatment), relaxation time using Bodysonic (RestB), and relaxation time not using Bodysonic (RestN). The subjects were 8 dentists working at our university (5 males,3 females, with a total of 30 experiments).5 of them were less than thirty years old while 3 of them were more than forty.
The summary of the results is shown below.
1) Reveral rate of Eye-movement was Treatment<RestN<RestB. The θ- wave and α- wave were RestN>RestB>Treatment, the β- low wave and β- high wave were RestB>RestN>Treatment.
2) As for the reveral rate of each index of treatment: Eye-movement was significantly different with those over 40 years old at P<0.01 and the θ- wave was at P<0.05. α- wave and β- low wave, β high-wave was significantly different from those under 30 years old at P<0.01.
3) For RestB: Eye-movement, θ- wave and β-low wave showed a higher rate for those under 30, while the α- wave and β- high wave showed a higher rate for those over 40 but neither of them showed any signifigant differences.
4) For RestN: Eye-movement, θ- wave and β- high wave showed a higher rate for those under 30, while α- wave and β- low wave showed a higher rate for those over 40 but neither of them showed any signifigant differences.

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A comparative study was conducted of the biting force of children who had not suffered from caries with those who had slight caries. At the same time, the group which had experienced caries was further investigated after crown restoration.
The subjects totaled 96.38 of those,20 boys and 18 girls had healthy teeth; 58 others,30 boys and 28 girls, had been treated by filling. These two groups were aged 3-6. Filling was performed after cavity preparation using adhesive composit resin. These were also then treated with occulusal ajustment and polishing. In some cases, we used a calcium hydroxide preparation for the indirect pulp capping.
The biting force was measured with the biting force measuring apparatus MPM-3000 (NIHON KOHDEN).
The results were summerized as follows.
1) The biting force for the healthy group was as follows: 20.1±1.9kg for the right second deciduous molar (below: right E), for the left second deciduous molar (below: left E) 19.5±2.4kg, the right first deciduous molar (below: right D) 18.9±2.4 kg, and the left first deciduous molar (below: left D) was 18.3±2.8kg. The values were slightly higher for the second deciduous molars.
2) Comparing the biting force before and after treatment for the group treated by filling, right E, left E, right D and left D were 14.5±3.7 kg,14.7±35 kg,13.9±2.7 kg and 14.2±3.1 kg before treatment, and 18.8±2.5kg,18.4±2.5 kg,17.8±2.3 kg and 17.3±2.7 kg after treatment respectively. In all cases, the value after treatment was significantly higher than before treatment (p<0.01).
3) The relative biting force for the group due to have fillings, compared with that of the healthy group, was as follows: 72.6% for right E,75.4% for left E,73.5% for right D and 77.6% for left D. The average was 74.8±2.2%.
4) The relative biting force of those who were treated with fillings was as follows: 93.5% for right E,94.4% for left E,94.2% for right D and 94.5% for left D. The average was 94.2±0.5%.

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The purpose of the present study was to clarify the changes in fluoride concentrations of the surface enamel of young permanent incisors just after eruption.
Fluoride concentrations and the acid dissolution rate of the surface enamel in the six normal lower central incisors in situ were measured by atlenamel micro-sampling technique.
Samples obtained were from four males and two females with an average age of 6.6 yr.
The fluoride concentration of the surface enamel in situ were compared with those of the extracted teeth.
The results were as follows:
1) Mean Ca/P (w/w) values was 1.96.
2) The acid dissolution rate had a tendency to decrease from the enamel surface towerd the deep layer. There was a reversed relationship between the fluoride concentration and acid solbility.
3) The fluoride concentration was decreased proportionally from the enamel surface toward the inner part.
4) The fluoride concentrations in teeth just after eruption was a significantly lower than those of the extracted teeth at the layer deeper than 3μm. (P<0.05)

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As a part of the study of the development of the occlusal function in children, It was decided that the department of pediatric dentistries of six colleges would work together and examine the longitudinal change of the occlusal contact around the time of the eruption of the first permanent molar four times every six months.
The results obtained at the first examination (with the time of the early occlusion of the first permanent molars, the average age being 7 years and 2 months. ) were as follows.
1) As the occlusal contact area of the mandibular first permanent molar increased, the occlusal force and the occlusal contact area of the deciduous second molar tended to increase. There was no relationship between the occlusal contact area of the mandibular first permanent molar and the occlusal pressure of the mandibular deciduous second molar.
2) In the mandibular first permanent molar, the occlusal force tended to increase and the occlusal pressure tended to decrease, with increase of the occlusal contact area.
3) There was a correlation between the root length and the occlusal force in the mandibular first permanent molar, but there was no correlation in the mandibular deciduous second molar.
4) As the occlusal contact area of the mandibular permanent molars increased, the occlusal contact area and the occlusal force of the total dentition tended to increase. We were not able to show a regular change in the occlusal pressure of the total dentition.

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In order to clarify the forms and conditions of the accessory canals on the pulpal chamber floor of human primary molars, serial sectional specimens of 76 human primary molars obtained from child skulls were examined histologically. Photographic images of the anatomical forms of the pulpal chamber floors were processed by computer to determine the size of the accessory canals. The travel patterns and forms of the accessory canals were analyzed three-dimensionally. Comparative studies between mature (root formed) and immature (root unformed) human primary molars were also carried out in order to understand the aged changes in the anatomical structure of the pulpal chamber floor and age related conditions of the accessory canals. The following results were obtained:
1. Dentin in the pulpal chamber floor of mature primary molars was found to be composed by two layers, but this two-layered structure was not found in immature primary molars. The thickness of the pulpal chamber floor was significantly greater in mature primary molars than in immature primary molars (p< 0.01).
2. Accessory canals were observed in all 76 primary molars (275 canals in total, with an average of 3.6 per tooth). There was, however, no significant difference in the number of occurrences of accessory canals between mature and immature primary molars.
3. The travel patterns of the accessory canals were classified into four different types. The number of accessory canals of the transporting type was significantly higher in immature primary molars than in mature primary molars (p< 0.01).
4. There were no significant differences in the lengths and inner diameters of the accessory canals between mature and immature primary molars. The lengths and inner diameters of the accessory canals of the transporting type were much larger than those of the non-transporting type. The wider accessory canals were generally found to run longer than the narrow ones.
5. Two different forms of accessory canals, tubular type and coral-shaped, were found. The number of tubular type accessory canals was significantly greater than the number of coral-shaped canals.

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The purpose of this study was to establish a new DNA extract method in humans the toothbrush. This method is considered to be one of the most useful approachs in the dental area because it confines the damage to the minimum against body injury and does not cause the patient any anxiety. The following are the results of the present investigation.
(1) A high molecular weight DNA was obtained from all of the patients tested.
(2) The level of the amount of extracted DNA from the tongue was significantly higher than that of the gingival and mucousmembrane site.
(3) For the amount of DNA recovered, it was shown that with 10 strokes were much more was recovered than with 1 stroke on each site in this study.
(4) Using the primer which responded especially to human DNA, we were able to amplify the tested samples using the polymerase chain reaction.
We concluded that the new DNA extraction method using tooth brush could be used as a useful tool to study the dentition abnormalities caused by gentincal factors such as conginital missing, teeth fused teeth and supernumerary teeth. Key words: Toothbrush, Human DNA extraction method, Polymerase chain reaction (PCR)

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The authors had reported that C 57 BR/cdJ and C 57 L/J strain mice showed high rates, and C 3 H/HeJ, AKR/J and RF/J showed medium rates, and A/HeJ and C 57 BL/6 J showed low appearance rates of the gutter shaped root. We investigated whether the M 2 had gutter shaped root indicated absolutely and relatively a degenerating tendancy or not by measuring the buccolingal and mesiodistal diameters of M 1 (lower the first molar), M 2 (lower the second molar) and, M 3 (lower the third molar), and the root length of M 2 in the above seven inbred strains of mice having different appearance rates of the gutter shaped root. The following were the results of the present study.
1. The buccolingual and mesiodistal crown dimensions of each molar did not show small or large tendencies in two strains with high appearance rates compared with the medium and low appearance rates of the gutter shaped root.
2. The rates of the mesiodistal crown diameters of M 2 with the gutter shaped root for three molars of seven strains of mice did not show small and large tendencies compared with those of the low and medium appearance rates of the gutter shaped root as a relative analysis.
3. The root length of M 2 in two strains of mice with high appeared rates of the gutter shaped root were significantly longer than those of other strains.
The results suggested that the gutter shaped root did not appeared as degeneration but as deformation by mutated genes.

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Immature permanent teeth suffering from root resorption as results of dental trauma, ectopic eruption of the neighboring tooth, auto-transplantation, and cysts, were clinically analysed to investigate their prognosis. The material included 59 teeth from 41 patients, aged 7 to 12 at the primary visit.
External and internal root resorption occured due to the trauma. The follow-up examination varied from 2 to 19 years, with average of 9 years. It was possible to recognize five types of root resorption.
Transient external resorption was observed in 5 vital teeth following root frature, luxation and albeolar bone fracture. This resorption showed small superficial resorption lacunae, and was repaired with hard tissue (Type I).
Another 46 teeth had endodontic therapy. Internal root resorption was radiographically characterized by an oval shaped increase in the size of the pulp chamber, associated with inflammation in the pulp or process to pulp necrosis in 4 teeth. After the start of endodontic therapy, resorption stopped (Type II).
External root resorption was observed in 42 teeth. In 13 teeth, resorption area of both root and albeolar bone was seen with pulpitis or pulp necrosis. By means of endodontic therapy, resorption was arrested (Type III). In some of them, the resorption lacunae were repaired with deposition of hard tissue.
However, in 11 teeth which had suffered displacement injuries, albeolar bone fracture, and avulsion, continuous extensive resorption was oberved. Endodontic therapy and endodontic surger had a slight influence on this resorption (Type IV).
In 18 teeth, dento-albeolar ankylosis was recognized by the infra-occlusion, and endodontic therapy showed little effect on the resorptive process (Type V). The radiographs revealed disappearance of the normal periodontal space and continuous replacement of root substance with bone, with or without radiolusency. As delayed findings, tunneling resortption and merginal bone loss were observed. In 5 teeth infrapositioning ceased. Besides this, the auto-transplanted tooth had the exetrnal reorption type III.
The root resorption in seven teeth resulted from ectopic eruption of the neighbouring canines or second premolars in patients with extensive crowding in the upper jaw other than the dental trauma. A folliculr dental cyst was also suspected to absorb the mesial root of its neighbouring mandibular first molar. When the suspected causes were removed, this resorption ceased in all the 8 teeth.

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On the basis of the results of a 9-year secular survey,432 homogeneous individuals of Hirokamimura, Niigata Prefecture were examined for the influence of the treated or untreated condition of deciduous molar caries on first molar caries. The Treated or untreated condition of deciduous molar caries was surveyed by healthy periods up to the contraction of the caries. The unhealthy group also represented a group in which first molar of each healthy group had contracted caries during the healthy period, and the X2 test of independence was carried out between items of either the healthy group or unhealthy group and the treated or untreated condition of deciduous molars for each year.
The following results were obtained;
1. The group which contracted first molar caries within one year of the confirmation of its eruption showed no significant correlation between first molar caries and either treated or untreated condition the caries.
2. The tooth types which were contributive to the healthiness of the first molar with a strong correlation were the first deciduous molars and especially the lower jaw to a more frequent extent for the treatment and the second deciduous molar with a strong correlation for the nontreatment. The group which was healthy for one year following the eruption showed a correlation only for the mandibular second deciduous molar and a correlation for the maxillary deciduous molar for a longer healthy period.
3. The treatments which showed the greatest contribution rate in each test belonged all to the healthy group, and the treatment of the deciduous dentition deciduous molars showed a correlation with the health of the first molars. As for treatments, the application of a caries progression inhibitor was confined to the healthy group for two years, and the group which was further healthy underwent a filling and repair treatment.
4. The nontreatment which showed the greatest contribution rate in each test, C, belonged all to the healthy group, C4 belonged all to the unhealthy side, representing only the group contracting caries within two years.

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In order to develop a self-etching sealant which does not contain either ethanol or water, a basic study was conducted.
As the first step, an experimento n the dissolution of hydroxyapatite of which the teeth are mainly composed was carried out, to investigate the etching ability of newly prepared sealant which consisted of phosphate monomer.
The following results were obtained, which indicated that the all-in-one-system sealant can be an alternative material as a sealant.
1) The experimental sealant containing phosphate monomer was able to dissolve hydroxyapatite in a dry condition.
2) During the early reaction stage, the dissolution depended largely on the dampness of the hydroxyapatite.
The amount of wet hydroxyapatite dissolved to the experimental sealant#1 (phosphate monomer: dilution monomer=5: 5) or sealant#2 (2: 8) was 9 times or 18 times more than the dry apatite respectively for the first one hour.
3) The amount of dissolution was dependent on the phosphate monomer content.

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In this report, transverse serial sections were employed to investigate the shape of the root canals of mandibular deciduous central incisors.
Twenty-one mandibular deciduous central incisors were decalcified in nitric acid and embedded in celloidin. Transverse serial sections were made, stained with hematoxylin and eosin and studied microscopically.
Root canal forms were classfied into three types: simple, isthmus and compound-round. The root canal itself was divided into thirds: coronal, middle and apical.
The following results were obtained;
1. Though the isthmus type was frequent in the middle and apical portions, in all portions the root canal was generally of the simple type.
2. Lateral branches occurred in two(9.5%) of twenty-one teeth, the all of which were in the apical portion.
3. No apical ramification occurred.
4. No adherent denticles were observed in twenty-one teeth. Of the twenty-one teeth observed, five were vital. Free denticles were observed in three of those five.
5. In the cross-cut sections of the middle of the established portions, we measured the labio-lingual and mesio-distal diameters of the root canals and the minimum distance from the root canal to the cement surface. The labio-lingual diameter averaged 1.14 mm in the coronal third,0.84 mm in the middle third and 0.47 mm in the apical third. The mesio-distal diameter averaged 0.79 mm in the coronal third,0.51 mm in the middle third and 0.31 mm in the apical third. In all portions, the shortest distance between root canal and cement surface averaged less than 1 mm.

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We experiensed a case of the Sturge-Weber syndrome in a 6-year,3 month old boy. We have followed him for dental treatment and maintenance of his oral hygiene for thirteen years. He fulfilled the three major symptoms of this syndrome, involving nevus flammeus occuring on both the right and the left sides of the face, bilateral brain calcification presenting as gyriform double contoured lines and glaucoma. The other findings were epilepsy, mental retardation and diplegia. Intraoral angiomatosis occured on both upper and lower lips, gingiva and palate. Delayed eruption of the permanent teeth and irregular positioning of teeth were observed. Vascular gingival hyperplasia was seen at several locations, being distingished from fibrous hyperplasia, which may accompany medication with diphenyl hydantoin. Histologically the specimen which was removed surgically from the hyperplasia of gingiva was diagnosed as epulis haemangiomatosa.

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Usually mucoceles are surgically removed. However, they often recur, especially when the child continues the habit of thumb sucking or lip biting that threatens to induce them. Between December 1988 and September 1995, we treated 49 children for mucoceles that originated in their minor salivary gland.
Splints were given to 20 of these children. The effectiveness could be assessed in 18 chidren, eight of which had developed mucoceles because of habitual behavior. Splints were fitted to the upper or lower jaw, and some FKO splints were used. All splints were 2-3 mm thick in the molar region and prevented habitual lip biting or thumb sucking.
After 1 month, they were judged as “effective” if the mucocele had become smaller or had disappeared, or as “non-effective” if the mucocele had not changed or had become bigger.
We had 3 effective cases, in which the children continued to use the splints for another two months. We had 5 non-effective cases, in whichi the chidren had the mucoceles removed surgically and then used splints to prevent a recurrence. Our follow-up ranged from 4 months to 5 years and showed that splint therapy prevented any recurrence, even in the cases originally judged as “noneffective”.

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Four cases of eruption failure of the first permanent molar were clinically examined for their causes and treatment of choice, course and duration.
1) The age of the patients ranged from 7 years 11 months to 9 years 6 months when diagnosed.
2) In all cases, there were existing masses above or around the crown of the impacted first permanent molars, that were considered to be related to eruption failure; they were diagnosed clinically or histopathologically as tooth-like structures, complex odontoma, compound odontoma and ameloblastic fibro-odontoma, respectively.
3) In three cases, the fenestration was made including the removal of the surrounding bone of the impacted tooth crown after a certain period from the initial treatment of the surgical removal of the causative masses, and the impacted first permanent molars successfully erupted thereafter. In another case, traction was tried as a treatment of choice 4 months after initial treatment composed of the surgical removal of the causative masses, but was discontinued after 3 months without the expected result. The impacted tooth, however, finally erupted after an additional observation period of one year.
4) Eruption guidance was successfully completed in all cases and the duration of guidance ranged from 7 months to one year and 7 months.

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Epidermolysis bullosa is a rare disease characterized by bullae or vesicles occurring on the skin or mucosal surface spontaneously or after a minor trauma. This disease is classified into four main groups and further into sixteen subgroups.
Recessive dystrophic epidermolysis bullosa causes contraction scars at the commissure of the mouth, so that tooth brushing becomes difficult, causing the teeth to become susceptable to severe dental caries. It is also difficult to undertake such dental treatment as pulp treatment of the molars and placement of space maintainers. Dental caries prevention is therefore having considered indispensable.
This patient was diagnosed as recessive dystrophic epidermolysis bullosa. The patient was given active oral hygiene management from the age of eight to seventeen.
The following findings were obtained:
1. Trismus was found and the buccal and labial vestibules were obliterated with scar tissue. It was therefore necessary to improve the form of the common tooth-brush obtainable on the market, which enabled the tooth-brush to be applied to the buccal surface of molar and did not aggravate intraoral bullae.
2. Since his dietary pattern was inclined toward soft foods, his caries susceptibility seemed to be higher. Therefore preventive methods such as temporary sealing of erupting molar by fluoridecontaining cement and fluoride mouth rinsing were performed additionally.
3. The oral hygiene condition was improved by the efforts of the patient and his family, so that no new caries have been found for nine years.

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Fused deciduous teeth can be found with a high incidence in the clinical area of pediatric dentistry. However, the incidence of fused permanent teeth is lower than that of fused deciduous teeth. A 12year one-month old boy presented with a case of fused permanent teeth involving the maxillary anterior teeth (fused teeth of the right central incisor and lateral incisor) which is one of the rarest exampies among fused permanent teeth cases. We report here the results of the dental evaluation of this case.
1. According to the answers to the questionnaire, the fused deciduous teeth were not found during the deciduous dentition.
2. When the mesio-distal crown size of_??__??__??_was measured separately,1 showed a value less than -3S. D. while_2_was within the average range.
3. Except_??__??__??_and_5, the mesio-distal crown size of all maxillary teeth were within the average range.
4. Using roentgenographic cephalometry, it was indicated that the size of the maxilla and those of the mandible were within normal ranges.

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A 4-year 5-month-old boy appeared at our hospital with dental caries. The boy continued to receive regular dental examination after treatment of the caries, and at 9 years 7 months of age, he complained of painless swelling of the mandibular left molar region. After stomatic examination, radiography and histopathological examination, a follicular dental cyst of the mandibular left second premolar tooth involvimg the dental germ was diagnosed. In addition, orthopantomography revealed a follicular dental cyst of the maxillary left first premolar tooth involving the dental germ. Fenestration surgery was performed on both regions. Ten months after surgery, the mandibular second premolar tooth began to erupt such that the top of the cuspid of the tooth on the buccal and lingual sides was visible macroscopically. However, since there was insufficient space (for the growing tooth), the first molar tooth was moved distally so that it was contained in the dental arch.
Three months after surgery, the maxillary first premolar tooth erupted to occupy more than onethird of its crown. This tooth, however, had mesioclination that was likely to interfer with the erupting canine tooth. The tooth was therefore moved distally so that the canine tooth and the firest premolar tooth were led into the dental arch. An Orthopantomogram taken at 10 months after surgery showed that the radiolusent figure of the cyst was considerably reduced, suggesting that the cyst was being replaced with new bone.
At 3 years 8 month after surgery, although the roots of the maxillary first premolar tooth and the mandibular second premolar tooth were curved and shorter than the controls on the other side, the apexes of these teeth had been closed, forming roots, indicating that treatment had been successful.
On the basis of this present experience, we conclude that fenestration is a very useful surgical treatment for follicular dental cyst in younger patients and that displaced dental germ can be replaced in the dental arch using appropriate treatment.

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The Sotos syndrome is also called cerebral gigantism. It is a syndrome complicated by macrocrania and mental retardation and exhibits symptoms similar to overgrowth and acromegaly. Maxillary protrusion, mandibular prognathism and high palate are the characteristic oral symptoms of this syndrome. Although the cause of this syndrome remains unknown, there is a good possibility that it is caused by dominant autosomal inheritance.
The patient was a 10 year 6 month old male who weights 28 kg and is 129.5 cm tall. However, because the patient suffers from scoliosis, he is shorter than the national average (138.7+/-5.9 cm).
Complications of The Sotos syndrome, such as, funnel breast, protrusion of the forehead and hypertension of the eyelids were detected.
With regard to the intraoral cavity findings, the occlusal relationship of the first permanent molars showed Angle class II occlusion, maxillary prognathism and a high palate was detected. The results of cephalometric analyses showed that the SNP and SNB were smaller than average, the SNA was within the normal range but small, and the maxilla and mandible were underdeveloped and positioned posterior to the base of the skull. Furthermore, even though the gonial angle was within normal range, the mandible showed posterior rotation.

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Bolheal interacts with fibrin which forms during the final stage of blood coagulation to cause the tissues to come together and close the wound. It is composed of fibrinogen, blood coagulation fac-torXIII, thrombin, calcium chloride and aprotinin.
Between April 1992 and November 1993, the effectiveness of Bolheal as a tissue glue was studied in 5 cases of extracted supernumerary teeth impacted in the incisal area in children visiting the pedo-dontic department of Aichi-Gakuin university Dental College and Takenoko Dental Clinin. The sub-jects in this study were 4 boys with ages ranging from 5 years and 4 months to 7 years and 4 months, and one girl 6 years and 5 month old.
The results are as follows.
1) Among the 5 subjects, 3 of the boys and one girl had normal eruptive direction and mono cuspid type crown morphology. The other child had eruption in the normal direction with mono cuspid type crown morphology.
2) After removed of the supernumerary teeth, Bolheal was sprayed on the wound of the palatine mucosa using the Bolheal pharmacal instrument set.
3) No symptoms of disconfort were experienced after tooth extraction.
4) Bolheal was found to be effective in stopping bleeding and in stimulating healing of the wound.

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Hand-Schuller-Christian disease is characterized by proliferation of histiocytes with the classic triad including bone lesions, exophthalmus and diabetes insipidus. In the oro-facial region, clinical features such as gingivitis, jaw pain, jaw swelling, exfoliation and mobillity of teeth are reported.
We experienced a 13-year-1-month-old girl who had been sufferring from Hand-Schuller-Christian disease and healed at the age of 12 years. Her chief complaint was malocclusion with delayed eruption of parmanent teeth.
Her clinical findings were as follows:
1) Her hight and weight were bellow the -2 SD line in the cross sectional growth chart, and her bone age was delayed 2 years.
2) The profilogram revealed that the Middle face growth was retarded.
3) All the first permanent molars were unerupted.
4) The lower second premolars showed ectpic eruption.
5) Panoramic X-ray showed root dwarfism of_??__??__??_, malformation and hypoplasia of _??__??__??_. We suspected that these teeth anomalies had resulted from Hand -Schuller-Christian disease, because the period of the formation of these teeth was coincident with the time of the occurrence of her facial palsy and eczema.
6) Histopathological examination of the extracted lower right second molar and lower left second premolar showed partial enamel defects and irregular dentinal tubules.

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