In order to clarify the changes in sequential occlusal aspects in children, we developed a system of superimposing recorded three-dimensional measurement data of tooth surfaces by using the threedimensional contact digitizer with a touch sensor probe. The evaluation of the accuracy of this system using the standard block and first molars proved to be highly precise.
By application of this system, quantification and visualization of dental wear on the primary right second molar were investigated on the serial dental casts taken at 6 years,8 months 9 years,4 months and 10 years,9 months of age from the same child.
As a result, quantification of dental wear was 4.6 mm3 between 6 years,8 months and 9 years,4months of age,2.1 mm3 between 9 years,4 months and 10 years,9 months of age. A all of the cusps except for the hypocone demonstrated that the steep slope changed more horizontality in visualization of dental wear.
In conclusion, it is a matter of great importance to clarify the relationship between occlusal aspects and the function of mandibular movement by a future development of this system.

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Embryonic development of the mammalian tongue involves unique cellular events, e. g., the migration of myogenic precursor cells from the occipital somites and their differentiation into myoblasts in the tongue primordium. We aimed here at scrutinizing the morphogenesis of the mouse tongue primordium and temporo-spatial expression of the myoblast markers, i. e., Desmin and MyoD. To this end, ICR mouse embryos at E 10 through E 18 were subjected to analyses. Embryos collected at discrete days were embedded in paraffin so that serial frontal- or sagittal-sections could be prepared for histomorphometry and immunohistochemistry. Histologic observations showed that the lateral lingual swellings, i. e. the initial morphologic marker of the tongue primordium, became discernible at E 11.0, followed by their fusion and rapid growth during the next 24 hours (E 11.0-12.0). Morphometric analysis also confirmed that the rapid growth of the tongue primordium accompanied cell proliferation without any marked accumulation of extracellular matrices. Of interest was that both Desmin and MyoD were expressed concomitantly in the tongue primordium at E 11.4 when the rapid cell proliferation commenced. The results led to the conclusion that the differentiation of somite-derived precursor cells into myoblasts is not responsible for the formation of lateral lingual swellings but is involved directly in triggering and modulating tongue morphogenesis and growth.

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A mandibular excursion with the occlusal contacts is one of the fundamental movements of the lower jaw and numerous studies have been carried out on this subject. Several studies have been conducted to estimate the ranges of this movement, including the protrusive and lateral excursion, although no article mentions about the area of possible movement. To clarify the functional difference between children with primary dentition and adults with permanent dentition, ten children and sixteen women with sound dentitions were selected for this study. Each of them was asked to perform the mandibular excursion with occlusal contacts. Curved mesh diagrams of mandibular excursion (CMDME), which showed the area of excursions, at the lower incisor, right and left canines, molars and condyles were constructed, the areas were calculated and compared. The results were follows:
1. Significant differences existed in the area of CMDME between the two groups at the lower incisor, canines and molars, but there were not observed at the condyles.
2. Children had statistically smaller lateral and vertical ranges than women at the lower incisor, canines and molars, although the condyles did not show this difference along lateral direction.
3. The CMDME at the lower incisor was symmetrical along the lateral direction and canines, molars and condyles showed mirror images between the right and left side with no statistical differences.
4. The ratios of the areas among the lower incisor, canines and molars were the same between the groups, although it was larger at condyles in children than adults
The differences between two groups clearly existed o n the mandibular excursions. Our results clearly revealed that the CMDME was able to show the areas of the mandibular excursions.

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Several articles have reported that there were findings concerning the cooperative activity in the head-neck region during mandibular opening and closing movements and/or mastication. To clarify whether these findings were actually present in children or not, we measured the habitual mandibular opening and closing movements and head movements in nineteen children with primary dentition and sixteen females with permanent dentition using an optoelectronic analyzing system (TRIMET) with 6degrees of movement at a sampling frequency of 1 00 Hz. The results of the children were then compared with those of the adults. The beginning posture of the head movement showed a slight upward inclination of the Frankfort horizontal plane. There was no significant difference between children and adults concerning both the head posture at the beginning position and the peak position of the head movement. After the examination of the maximal vertical range of head and mandibular movement and the maximal amount of head and mandibular rotation in the two groups, the head movements of the children seemed to consist of a much greater rotational component than of the adults. Variables for the maximal vertical range of the head movement correlated significantly to that of the mandibular movement according to the individual, and variables for the maximal rotational amount of the head movement also significantly correlated to that of the mandibular movement. It was consequently proved that a larger head movement was found in proportion to a larger mandibular movement. This tendency was more strongly evident in the adults than in the children. It became clear that there was more considerable variance in the results of the head movement than in those of the mandibular movement.

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To investigate the role of growth factors in the proliferation of human periodontal ligament fibroblasts (HPLF), we evaluated the influence of The insulin-like growth factor- I (IGF- I ) and The plate-derived growth factor (PDGF). Furthermore, we evaluated the effects of adenosine and ATP, which are abundant during bleeding, on the proliferation of HPLF.
When IGF- I and PDGF were incubated for 24 and 72 hours, concentration-dependent increases were demonstrated on the HPLF proliferation. On the other hand, when adenosine and ATP were added to HPLF, significant decreases in the cellular proliferation ability were detected at a concentration of 5×10^-4M. Thereafter, adenosine and ATP prevented potentiation of proliferation with IGF- I. In contrast, adenosine and ATP did not prevent potentiation of proliferation by PDGF. These results suggested increases in the proliferation of HPLF with IGF- I and PDGF, and the suppression abilities of adenosine and ATP on the proliferation of HPLF.

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The value of DIAGNOdent^TM(KaVo) was measured on the pit and fissure of 57 untreated molars and premolars using patients who visited the Pediatric Dental Clinic, Kyushu University Hospital. Comprehensive caries diagnosis was decided based on inspection, palpation, dye lesion with the Caries Detector (Kurarey), and the value of the Caries Meter (Onuki). Based on these data, the features of the DIAGNOdent^TM value were evaluated, and the correlation with CO, C₁, and C₂, was investigated by comparing the value with that of the Caries Meter. The clinical usefulness of DIAGNOdentTM was also discussed.
There was no significant difference in the measurement values of DIAGNOdent^TM and the Caries Meter among the 3 researchers. The measurement value was obtained by measuring each experimental tooth twice, and the variation of the two measurements was from 10 to 16% for each device and researcher. High correlation of R=0.68 was found with the logarithm approximation curve between the DIAGNOdentTM value and the Caries Meter value.
Based on the standard value of Caries Meter to diagnose caries, the DIAGNOdent^TM value of 15was judged to be the border between sound teeth and caries teeth, and 27 seemed to be the border of C1, and C2, by the obtained approximation curve.
By correlating the DIAGNOdent^TM value with comprehensive caries diagnosis, there was no significant difference in the DIAGNOdentTM value between the sound and C1, and CO and C1,. I t was considered difficult to specify the range of CO. by using DIAGNOdentTM base on the present results.

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In this report the relationship of the location of impacted or delayed erupted upper canines with selection of treatment method was investigated.54 teeth of 44 patients who were treated in our clinic during the period from January 1990 to April 2002 were examined for causes, location of tooth germ, treatment method, and treatment duration. Locations of the upper canine germ were evaluated based on the sectored lesion, the vertical distance to the occlusal plane and the angle of mesial inclination to the midline shown on orthopantomograms.
1. The main cause of impaction and delayed eruption of upper canines was the abnormality of the location and the direction of eruption of the upper canine tooth germ.
2. The traction method (traction group) was applied to 26 teeth, while non-traction cases (non-traction group) for which the extraction of preceding primary teeth, space maintenance and fenestration were performed amounted to 25 teeth. In some cases the extraction of the impacted upper canine or upper lateral incisor were performed.
3. Distribution of the sector where the tooth germ was located, and the vertical distance and the angle of mesial inclination in the traction group differed significantly from of the non-traction group.
4. There was an apparent relationship between the vertical distance of the canine tooth germ and the treatment duration in the traction group.

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[in Japanese]

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Human β- defensins (hBDs) are a group of antimicrobial peptide mainly expressed in the epithelial cells of many organs including squamous and glandular epithelia. hBD-1, -2 and -3 have been detected in oral epithelium, consistent with their function as a protective barrier to resist bacterial infection in the oral cavity. The present study investigated the localization pattern and expression level of the hBDs mRNA in gingival tissue using the surgical discards of children. With in situ hybridization, the hBD-1, -2 and -3 mRNA were detected in the upper spinous and granular layer. The expression levels were quantified using a real-time PCR method. No significant difference in the expression level was observed between hBDs. The results show the same pattern of localization and level of expression on hBD-1, -2 and -3 mRNA, indicating that the hBDs may function together in gingival tissues.

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The purpose of this study is to compare the electromotive permeation anesthesia injector (EAT)with the effects of the manual formula permeation anesthesia injector (MAI) in dental treatment for child patients.
The medical interview and the VAS (visual analogue scale) methods were conducted to evaluate the effects of anesthesia in 61 children, and the following results were obtained.
1) Prior to administering anesthesia,49.2% of the children with EAI and 78.7% with MAI felt of uneasy, respectively.
2) When the strength of the pain during anesthesia was evaluated with VAS at five levels of pain from 0 to 4, level one was the most frequent with 47.5% with EAI and the level two was 44.3% with MAI.
3) Children who felt pain during dental treatment amounted to 1.6% with EAI and 3.3% with MAI, respectively.
4) 67.2% of the patients greatly preferred having dental treatment under EAI. In conclusion, it was suggested that the EAI was clinically useful in the pediatric dentistry.

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Changes in disease structure and coming of a society with a population of small children are apparently exerting a large effect on dental care during childhood. For the purpose of obtaining an index in carrying out in the dentistry in proportion to demand local community, this study was continuously to investigate the actual status of patients making then first visit for the 5 years from 1997 years to the Pediatric Dentistry Clinic of Meikai University compared to the previous investigation (1992-1996).
1. In this investigation the total number of patients visiting initially was 2310, and it increased from the previous investigation (1621). The number of patient for the 3 years during the latter half of this investigation decreased.
2. The 3-year-old children showed the highest rate among the patients making then first visit. Patient under 6-years of age amounted to about 60% of all the outpatients and this tendency was the same as the previous investigation.
3. An investigation concerning the distance from the home to the clinic showed that about 32% of all of the outpatients were the within the 5 km range. About 25% of them however were from a distance of over 15 km distance, this being greater than the previous investigation, by about 10%.
4. The Chief complaint of dental caries and toothache appeared in about 50% of the patients and this drastically decreased since the previous investigation, by about 70%.
5. The number of df and DMF showed a higher score than that of the previous investigation and this seemed to show a double pole of the dental caries proportions.
6. The number of patients referred from the other general practitioner (592) increased in the previous investigation (422), and it accounted for about 25% of all of the patients. The 4-year-old children as the generation and 10-15 km range as the distance from the house to clinic were the most abundant among the patients referred.
7. The number of disabled children amounted to 73, and showed about the same as in the previous investigation.

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Small-group learning was conducted during clinical training for pediatric dentistry. One hundred and thirteen 5th-year dental students of Nippon Dental University Hospital in Tokyo participated in the learning program. Small-group learning was then evaluated using a questionnaire that was distributed to the students, and the following results were obtained:
1) The mean ratings (5 grades of rating) of the facilitator evaluations, the evaluations of small-group learning progress and the evaluations of satisfaction with small-group learning were 4.64±0.56,4.34±0.68 and 4.43 0.61 respectively.
2) No differences in the evaluations of full-time and part-time facilitators were seen.
3) Student satisfaction with small-group learning was strongly affected by the facilitator evaluations and the degree of progress made in the small-group learning sessions.
4) Topics for voluntary learning had no effect on the facilitator evaluations, but had significant effect on the progress of the small-group learning sessions and the satisfaction with the small-group learning.
5) Problems that effect on the satisfaction with the small-group learning were shortage of time spent on specific tasks during the small-group learning sessions and lack of proper educational facilities for the small-group learning.
These results suggest that a sufficient amount of time spent on voluntary learning and discussion and indication of topics, which are more interesting to dental students, are necessary to improve satisfaction with small-group learning during clinical training for pediatric dentistry.

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To investigate the influence of factors at alveolar cleft sites and the nursing condition on the growth of deciduous dental arch, the dental arch sizes, the deciduous dentition and the growth of the upper dental arch were examined in 197 cleft lip/palate patients in 3 years old, who had undergone overall medico-dental child cares since the neonatal period at the Cleft Lip/palate Center, Fujita Health University.
The upper inter-deciduous canine distance was larger in the unilateral cleft lip (UCL) and the bilateral cleft lip (BCL) groups, and smaller in the unilateral cleft lip/palate (UCLP), the bilateral cleft lip/palate (BCLP) and the cleft palate (CP) groups. The upper inter-deciduous canine distance was also smaller in cases with congenitally missing teeth at the cleft site. The midline of the upper dental arch shifted toward the affected side in cases with tooth lost at the cleft site, while it shifted toward the healthy side in cases with the supernumerary tooth at the cleft site. In the UCLP and BCLP groups, more teeth appeared within the crossbite. The terminal plane of the secondary deciduous molars was shown to be mostly of the mesial step type.
The amount of milk intake per feeding increased with the installation of palatal plate just after birth when newly born. Those who had larger dental arch showed that they drank larger amount of milk per feeding when they were when newly born.
It was concluded that the types of cleft and the number of teeth at cleft sites influenced the growth of the upper dental arch, and that the installation of the palatal plate increased the amount of milk intake per feeding which might accelerate the development of the upper dental arch.

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We found geminated teeth on the maxillary right lateral incisor to be impacted due to a tooth shape anomaly in a 7 year 2 month old girl. The germ of the developing maxillary right lateral incisor showed the tooth shape anomaly on a radiograph obtained to verify tooth trauma at the age of 2. When she was 7 years old, eruption of the maxillary right lateral incisor was delayed in comparison with that of the left lateral incisor. We considered normal eruption of the geminated teeth to be unlikely to occur. After the geminated teeth had been extracted, this tooth was intentionally replanted after occlusal reshaping and was closed over the mucoperiosteal flap. At the check-up one month later, we confirmed that this tooth had erupted. It had moved into the occlusal position 8 months after surgery. Root formation of this replanted tooth continued and the patient reported no discomfort at the regular follow-up visits. However, the replanted tooth did not show vital reaction on pulp diagnosis. She had no complaints of unpleasant symptoms during the orthodontic treatment, which had lasted for about 1 year and a half. Cure had been achieved by 11 years of age. The crown of the replanted tooth was reshaped with composite resin after completion of the orthodontic treatment. We attribute the good progress of this case to the following factors;
1. Extreme care was given to finishing treatment in a short time and to not damaging the periodontal ligament. The replanted tooth prevented ankylosis and tooth movement was made possible as a result.
2. The impacted tooth was again closed over the mucoperiosteal flap after treatment. We therefore considered the treated tooth to have good results because bacterial infection was kept to a minimum. The replanted tooth did not show vital reaction on pulp diagnosis. Root formation of this replanted tooth was however complete at a later time, and we will be able to verify full clinical function of the replanted tooth by long-term follow up.

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We experienced a very rare case of a patient with an impacted geminated tooth in the mid-line region of the maxilla. A 9-year-old Japanese female suffered from a chief complaint of dentia tarda of the right maxillary central incisor. Her past medical history showed nothing of significance. The intraoral findings showed that the right maxillary central incisor was not erupting despite complete eruption of the left maxillary central incisor. X-ray examination revealed an impacted geminated tooth in the mid-line region of the maxilla. The right maxillary central incisor and supernumerary tooth were united by dentin and enamel without having the pulp cavity jointly. The apex of this tooth was curved without closing. The crown of the geminated tooth was very large, so that this tooth was impacted due to a shortage of space for the eruption.
We removed part of the supernumenar y tooth from the crown of the geminated tooth providing a route of eruption. One month after the operation, the eruption of the geminated tooth was observed. We performed miner tooth movement to improve the malalignment of anterior tooth area due to dislocation of the geminated tooth. We subsequently carried out composite resin filling on the united region for of the geminated tooth for improvement of the crown shape.

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