The Authors conducted this to determine the actual status of new pediatric patients in order to reveal the entire scope and the changes over the years at a hospital in affiliation with Aichi-gakuin University, where these patients underwent dental based examinations from April 1993 to March 1994, and also from April 2003 to March 2004, on the basis of the application forms for the initial visit. The following conclusions were reached;
1. Total number of new patients: There were 412 new patients from April 1993 to March 1994 and 562 new patients from April 2003 to March 2004. The rate of increase was 36.4%. The mean age of the patients was 6.4 years in both periods.
2. The number of patients classified by month: From April 1993 to March 1994, it was greater in the months which corresponded to long vacations for primary school students and smaller in other months, while there was no dramatic change from April 2003 to March 2004.
3. The number of patients classified by day: From April 1993 to March 1994, every day showed similar values, except Thursday. In contrast, from April 2003 to March 2004, Monday and Saturday was showed significantly larger figures.
4. The percentage of patients classified by chief complaint:“caries treatment”and“oral care”accounted for more than 50% in both periods. For other chief complaints, there were not any remarkable changes in the 10 years.
5. The distribution of the domiciles of patients: In both periods, showed a higher proportion living in wards in the neighborhood of the hospital. The number of patients who lived in the suburbs of Nagoya showed an increase.

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The mutans streptococci, Streptococcus mutans and S. sobrinus, in habitat the human oral cavity, and primarily dental plaque, are considered to be major etiologic agents of dental caries in children. The colonization with age of each mutans streptococci and other oral streptococci and its relationship to caries prevalence in children are not yet fully understood. In this study, the species-specific PCR assays targeting gtf and 16S rRNA genes were developed, and the colonization of S. mutans, S. sobrinus, S. gordonii, S. sanguinis, S. oralis, S. anginosus and S. salivarius in plaque samples from 320 children (0 to 15 years old,20 subjects from each year of age) were assessed in relation to caries prevalence. The PCR assays enabled specific detection of 0.5 to 10 pg of genomic DNA, corresponding to 100 CFU of bacteria, of each species. In the plaque samples from 320 children who were referred to The Dental Hospital of Iwate Medical University and the affiliated nursery schools for dental treatment or followup treatment and who were the participants in the Survey of Dental Health and Welfare in Hiraizumi, Iwate prefecture, S. mutans was found most frequently, and S. sobrinus and S. gordonii were relatively infrequently detected. It was noted that S. sobrinus was found in the plaque samples from S. mutans-positive subjects. The percentages of subjects with S. mutans- and S. anginosus-positive increased with age, while the percentage of subjects with S. sanguinis-positive decreased. Furthermore, the subject-based analysis noted a positive correlation between S. mutans colonization and the caries score. The present findings of the cross-sectional study using the developed highly sensitive species-specific PCR assays therefore indicated that numerous oral streptococcal species including mutans streptococci were able to colonize quite early in childhood with plaque development, and thereafter the proportional change of the increase of S. mutans and S. anginosus and the decrease of S. sanguinis was able to occur with age. Furthermore, S. mutans was the predominant species that correlated with caries prevalence in children, regardless of age.

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In this study, we investigated the state of dental caries and treatment in children less than 3 years of age during the period of deciduous teeth of the eruption, for whom dental treatment is considered difficult.
The subjects were 138 children less than 3 years of age at the first examination, consisting of 87 boys and 51 girls, who underwent treatment of dental caries in the Department of Pediatric Dentistry of Tokyo Dental College Suidobashi Hospital during a period of 4 years 3 months from April in 2000. The following results were obtained.
1. The number of patients was slightly larger in the age groups of 1 year 6 months to 1 year 9 months and higher than 2 years.
2. The patients consulted our department most often with or without a letter of referral by a local dentist.
3. The total number of teeth with caries was 718, and the mean was 5.2 per patient. Some patients had dental caries in more than half the erupted teeth in each age group.
4. The rate of severe dental caries was higher in the patients aged less than 2 years of age, while in the patients aged more than 2 years of age, the rate of mild dental caries was only slightly higher.
5. Treatment was completed in less than 5 times in most of the patients.
6. Relatively complicated treatment was performed on the patients 1 year 6 months to 1 year 9 months of age, while for the patients aged more than 2 years of age, simple treatment was predominant.

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The purpose of this study was to investigate the actual s t atus as well as problems in the use of the rubberdam isolation technique for child patients. Random sample groups, which consisted of 101 general dentists and 21 pediatric dentists in Southern part of Kyushu, completed questionnaires anonymously. The results are as follows.
1. 20.8% of dentists in general practice were found to use this technique for child patients. They selected“Keeping the treatment area dry and clean” more commonly as their answers to the reason for using this technique as well as pediatric dentists.
2. 44.8% dentists in general practice who did not use this technique for child patients selected“It lowers the efficiency of treatment”more commonly as their answers to the reason for not using this technique.
3. Many of both groups were selected“the efficiency of treatment” as their answer concerning problems in using this technique.

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The purpose of this study is to clarify the status and awareness of female dentists.
A questionnaire survey was conducted in 2003 with 254 female members of the Japanese Society of Pediatric Dentistry (JSPD) and 191 female dentists who had graduated from a dental school (Control).
The following is a summary of our findings:
1. Most female dentists worked at the clinic every day. Half of them worked over 8 hours a day.
2. 70% of them were married. One third of them did not have any children. The average number of the children was 1.5.
3. Half of the JSPD members have joined the Japanese Association of Dentist (JAD). Only one third of the control group have joined JAD. Half of both groups have served on some post of the association. Most had no intention of doing this.
4. Most of the members wanted to participate in lecture or study classes. They cannot do this because of lack of time spare.
5. Most of the members have not volunteered for social works due to time pressure.

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The purpose of the present study was to obtain fundamental data about the tongue movements when swallowing in order to establish objective evaluation for the tongue movements by using the simultaneous recording system with the tongue pressure changes on the palate and the masticatory muscle activity.
Five subjects who were diagnosed to have normal deglutition, participated in the study. For measurements of the tongue movements, an artificial palatal plate was prepared, in which three strain gauges for measuring tongue pressure were set in three positions in the mid line of the palate, frontal, middle and rear parts of the palate antero-posterioly. The tongue pressure changes and the masticatory muscle activity were measured when swallowing 5,10 ml of water and saliva, respectively. The measurements were performed one hour later, and 1,2,3 days later after wearing the artificial palatal plate. The starting time of the deglutition was so defined that the larynx rose up to the anterior direction.
Though significant coefficient variation was found in the duration of the deglutition for 10 ml water among the days when the experiment was conducted after wearing the artificial palatal plate, no significant difference was found among the days in the first and second peak times of manifestation from the start of swallowing and in the maximum tongue pressure.
In addition, no significant difference among the days w as found either in the duration between the start of deglutition and each masticatory muscle activity.
In conclusion, the reproducibility of this syste m in measuring tongue pressure changes among the experimental days was confirmed, and tongue movements when swallowing were found to become smooth with time.

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The purpose of the present study was to investigate the influence of infant feeding methods on the subsequent growth of the inter canine width and the development of the bite force in children.
The questionnaire survey and oral examination were conducted with 338 children from 3 yrs to 5yrs old and their parents. The subjects were classified by feeding method during the first three months after birth into three groups, a breast-fed, bottle-fed, and a mixed-fed group. The inter-canine width of both jaws, the bite force between the upper and lower 2nd primary molars and the def teeth rate were calculated, and compared among the three groups.
The results obtained were as follows:
1) The inter-canine width in each jaw was found to show no significant differences among the three groups in all age groups. The rate of the inter-canine width was designated by the formula: the lower/upper×100(%), which was also found to show no significant differences among the three groups at each age.
2) There was no significant difference in the bite forces among the three groups at each age. These findings suggest that infant feeding methods up to three months after birth wer e not able to effect on the growth of bite force and inter-canine width namely the inter-canine width at all.

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The aim of this study was to establish of caries prevention, and to examine the relationship between dental caries and surroundings factors, based on life habits and caries activity during the deciduous dentition period. Furthermore, since glucosyltransferase, which is a synthetic enzyme of water insoluble glucan in mutans streptococci, is strongly involved in the occurrence of caries, the relationship between deciduous tooth caries and the expression of gtfB in Streptococcus mutans or gtfl in Streptococcus sobrinus was also investigated.
In this study, I research on 114 children in Nagano, and performed a caries activity test (Mucount®) and investigated environmental factors, by asking parents to fill out questionnaires. I also collected dental plaque from brushing from 36 children.
χ²analysis of the relationship between dental caries and environmental factors was performed. The expression of gff was also examined using Real-time PCR, and comparison evaluation was carried out by classifying the children into three groups based on the severity of their dental caries.
Among the results of the Real-time PCR analysis, the incidence of gtfB expression was 14.3% in the non-caries group,41.7% in the low caries group, and 100.0% in the high caries group, there was considerable gtfB expression in the high caries group. The incidence of gtfl expression was 8.3% in the low caries group, and 30.0% in the high caries group. More gtfB expression was consequently, noted in the caries group, and the gtfl expression was lower than the gtfB expression.
Furthermore, there is a tendency that for children who showed gtfB expression, the living environment was irregular, and the level of knowledge of the parents concerning caries was low.
These results suggested the occurrence of caries in deciduous tooth is related not only to the number of Streptococcus mutans and Streptococcus sobrinus, but also to pathogenic factors such as the gtfB and gffl expressions; Caries activity became higher under these conditions. It was also suggested that improvement in living environment is an important approach to prevent caries in deciduous tooth and to decrease the occurrence of serious caries.
It is considered that understanding of living environment, of the children and the bacterial risk during growth is useful for motivating their parents as an index of instruction in caries prevention.

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Sucking rhythm is produced by the interneurons located in the medial pontobulbar reticular formation although the motor output of the sucking-like activity is recorded in the trigeminal motor nucleus (Mot V) in the newborn rat brainstem. In this study the author focused on the electrophysiological properties and morphological features of the neurons in the nucleus reticularis pontis caudalis (PnC)in rats in the sucking stage.
The study consisted of a series of the following four experiments: (1)evaluation of the growth and behavioral development of rats in the sucking stage, (2)observation of the cytoarchitectonical features of the neurons retrogradely labeled with DiI in both the trigeminal mesencephalic nucleus (Mes V)and Mot V for localizing PnC, (3)evaluation of the electrophysiological properties of the neurons in PnC with the whole cell patch clamp recording in the brain slice preparation and (4)observation of the morphological features of the neurons in PnC with the Klüver-Barrera stain.
I identified the eruption of the mandibular incisors at 9 days, maxillary incisors at 11 days and both maxillary and mandibular molars at 19 days. Beginning of solid food feeding was identified at 18days.
Neurons labeled with DiI were located in both the Mes V and Mot V. In the transverse brainstem slices Mes V was visualized as a non-fixed form region, which consisted of simple small size neurons, while Mot V was visualized as an oval region, which consisted of multipolar medium size neurons. The electrophysiological properties of the PnC neurons changed with aging. In the PnC neuron current-voltage relationship with NMDA bath application was divided into two groups, the positive current response group and the negative current response group.
Synaptic responses in the PnC neurons elicited by stimulation of Mes V, Mot V or peritrigeminal area (Peri V) were obtained in 17 cases at both monosynaptic and polysynaptic latency. Morphological features of neurons in the PnC developed with aging as follows: growth of dendrite and myelin sheath, as well as increase in the number of gliacyte and pyramidal cells.
These data indicate that the physiological and morphological properties of PnC neurons in the rat brainstem through development change through out the sucking stage.

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The purpose of this study was to evaluate whether laser welding using an Nd-YAG laser could be used for appliances with an auxiliary spring in pediatric dental clinics. In particular, the elasticity rate and Vickers hardness were examined. A main line and an auxiliary spring were welded using the Nd-YAG laser. The laser welding involved a fiber diameter of 400μm, and a 900 mJ Nd-YAG laser beam, a pulse width of 5 pps and an irradiation time of 1 min. The elastic strain energy for laser welding using the Nd-YAG laser was significantly lower than that of argentums soldering using a flame. In addition, the Vickers hardness was low near the welding area of an auxiliary spring though there was no change in action area of an auxiliary spring. The results of the present study indicated that with laser welding, at the point of joining of the auxiliary spring and the main line, there was less change in the shape of the wire caused by heat when joining in comparison with argentums soldering using a flame, and that it was possible to apply the wire pressure to the teeth continuously.

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