The aim of this study was to examine relationships between the level of caries activity in preschool senior children and the increase of dental caries 3 years after the permanent teeth erupted. A total of 1133 preschool senior children aged 5-6 years were examined yearly during 3-year duration. A Caries Activity Test (Cariostat Test) was used at the first examination of this study. The results were as follows;
1. The caries prevalence rate of the subjects was 84.1% and the mean dft was 5.89 at the first examination.
2. There was a significant relationship between the CAT score and dft at the first examination (P < 0.001).
3. The subjects were divided into 3 risk groups by CAT score: low-risk group (20.4%), middle-risk group (43.3%) and high-risk group (36.3%).
4. Increments of DFT from 1 year to 3 years after the permanent tooth erupted for the high-risk group were more than twice for those of the low-risk group (P < 0.001). The prevalence of the permanent tooth decay for the high-risk group was also higher than that of the low-risk group (P < 0.001).
The results showed that the usage of the CAT Test for preschool senior children was useful to predict increase in permanent teeth caries over 3-year duration.

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The study compared CAT21^® test scores (Cariostat score) of plaque and saliva samples of 117 kindergarten pupils to check the congruency of both sampling methods. The scores were also compared with that of the subject’s “d” and “df” teeth. Test scores are based on color changes resulting from a decrease in pH brought about by presence of acid-producing microorganisms. Results revealed an early color change of the CAT21^® test solution of the saliva samples compared to that of plaque samples. However, the difference in the color change in both sampling procedures became negligible after 48 hours of incubation. Results revealed a statistically significant correlation between CAT21^® test scores of both sampling procedures and when compared with the mean “df” teeth.

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To clarify the effects of the applied during sedation with nitrous oxide (hereafter referred to as laughing gas) on the ability of muscles attached to the lower jaw to sense lower-jaw-position and on the sensation of muscle spindles attached to the lower jaw in patients with cerebral palsy (CP) using healthy adult subjects without functional abnormalities of the jaws and oral cavities as control subjects (hereafter referred to as healthy subjects). Experiments were performed under the following conditions: for each subject, before the inhalation of laughing gas (LG) and oxygen (air-inhalation condition: referred to as without LG inhalation) and during the inhalation of LG and oxygen (inhalation condition of LG and oxygen under LG-induced sedation: referred to as during LG inhalation). Subjects in the experiments were eight CP patients and eight healthy people as controls. The ability to discriminate lower-jaw-position was estimated by asking the subjects to determine whether the diameter of a test stick was larger or smaller than that of a reference stick after performing the following tasks: a) holding a reference stick between the central teeth of their upper and lower jaws for 5 s, and b) replacing the reference stick with a test stick and holding it at the same position for 5 s, and the test stick was then removed. The following findings were obtained.
1) In comparing discrimination ability in the absence of LG-induced sedation and that during LG-induced sedation of healthy control subjects, the rate of mis-estimation (RME) was significantly larger during LG-induced sedation than in the absence of LG-induced sedation for a test stick diameter (10.5 mm or 11.0 mm) larger than the reference stick diameter (10.0 mm) (P < 0.05). No significant differences were observed for any other test sticks (P > 0.05).
2) In comparing discrimination ability in the absence of LG-induced sedation and that during LG-induced sedation of CP patients, RME was significantly smaller during LG-induced sedation than in the absence of LG-induced sedation, when the test stick diameter (9.5 mm) was smaller than the reference stick diameter (P < 0.05). No significant differences were observed for any other test sticks (P > 0.05).
These results indicate that neural functions are inhibited at the upper level of the central nervous system in CP patients, leading to the attenuation of sustained increase in muscle tonus that is characteristic of CP patients. In summary, it seems that the LG has some inhibitory effect on the activity of γ-motor neurons innervating muscle spindles attached to the lower jaw via the upper level of the central nervous system and that this inhibitory effect contributes to an improvement in the discrimination ability.

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We performed measurement using a 3-dimensional measurement system in study models of children with anterior crossbite in the primary dentition treated using a chin cap and lingual arch, and evaluated changes in the dentition and occlusion after treatment based on measurement values and also using wire frame models. Comparing with the situation before treatment, the overbite of anterior teeth shows improvement to become shallow and the terminal plane becomes vertical type and the occlusal plane becomes flatter. Labioclination of upper anterior teeth, linguoclination of lower anterior teeth and backward movement of lower dentition are observed. Occlusal view shows that both upper and lower dental arch become semicircular configuration. The width, depth and height of the post-treatment dentition became closer to the standard values. Chin cap and lingual arch treatment for anterior crossbite during early childhood is effective, and also helpful in the normal development of occlusion in children.

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The effects of grape seed proanthocyanidins extract (GSPE, 3 mg in 100 g of high-calcium diet with a calcium content of 1697 mg/100 g) on rat metaphysis tibia formation following feeding of a low-calcium diet (30% of calcium in the standard diet) were investigated by examining bone density, mineral content, geometric and bone strength. Five-week old male Wistar rats (n = 40) were randomly divided into a control (Co) group, a low-calcium diet (LC) group, a low-calcium diet·high-calcium diet (LCH) group, and a low-calcium diet·high-calcium diet with supplementary GSPE (LCHG) group. The metaphysis tibia bones were analyzed using three-dimensional peripheral quantitative computed tomography (pQCT), while whole tibia bones were tested for mechanical resistance using a material testing machine. We found no significant differences in body weight among the 4 groups. All bone parameters in the LC group were significantly lower than these in the Co group (P < 0.01). Furthermore, trabecular bone density (TrBD), trabecular bone mineral content (TrBMC), cross-sectional moment of inertia to the reference axis y (yCSMI), and stress-strain index to the reference axis x (xSSI) in the LCHG group were significantly higher than those in the LCH group (P < 0.05; P < 0.01; P < 0.05; P < 0.05, respectively), while stiffness in the LCHG and LCH groups were significantly higher than that in the LC group (P < 0.01). We concluded that a mixture of high-calcium and GSPE in the diet has a more beneficial effect on bone formation for the treatment of metaphysis tibia bone debility in rats than does a high-calcium diet alone.

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The main ingredient of grape seed proanthocyanidin extract (GSPE), is proanthocyanidin, a kind of flavonoid. Proanthocyanidins are known to have a variety of biological regulatory activities, such as antioxidant effects; however, little is known the effects on bone. In the present study, we performed mechanical analysis using three-dimensional peripheral quantitative computed tomography (pQCT), bone strength tests and quantitative analysis of a combination therapy composed of high-calcium diet and GSPE fed to rats during their growth. Forty male Wistar rats, 5 weeks old, were divided randomly into control (A), low-calcium diet (B), low-calcium/high-calcium diet (C) and low-calcium/high-calcium diet with supplementary GSPE (D) groups. After 6 weeks, the tibias were removed and cortical bone density, cross-sectional area, mineral content, cortical bone thickness, periosteal perimeters, endosteal perimeters, and stress strain index (SSI) were measured. Invasive three-point bending tests, and quantitative analysis of Ca, P, Mg and Zn using inductively coupled plasma (ICP) spectral analysis were performed. Body weights were not significantly different in the 4 groups. Cortical bone density and mineral content in group D were significantly higher than those in group C (P < 0.01) as was the periosteal perimeter (P < 0.05). SSI and three-point bending test results for group D were not significantly different than those for group C, but recovery in group D was similar to that in the control group. As for the quantitative analysis, Ca, P, and Zn levels in group D were significantly higher than those in group C (P < 0.01). Our findings suggest that a combined therapy with a high-calcium diet and GSPE can improve the quality and strength of rat tibias during their growth.

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Lipopolysaccharide (LPS) and interferon-γ (IFN-γ) are external and internal activator of macrophages, respectively. During infection, adenosine has physiological effects at the site of inflammation mainly through four subtypes of adenosine receptors including A1, A2a, A2b, and A3. Moreover, A2a adenosine receptor is a critical part of the physiological negative feedback mechanism for limitation and termination of tissue-specific and systemic inflammatory responses. It was useful and meaningful to gain information about interaction with LPS, which generates the inflammation, and IFN-γ, which is a major activation factor for macrophages, and adenosine receptors, which terminate the inflammation. The aim of this study is to evaluate the abilities of LPS and IFN-γ on the expression of adenosine receptors in mouse macrophage cell lines RAW264 and J774. LPS increased the proliferation in RAW264, but not J774. IFN-γ didn’t alter the proliferation in RAW264 nor J774. LPS significantly potentiated the expression of all adenosine receptors in J774, but not in RAW, whereas IFN-γ markedly potentiated the expression of all adenosine receptors in RAW, but not in J774. These results suggest that LPS and IFN-γ may differently affect the expression of adenosine receptors in macrophage cell lines RAW264 and J774.

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Although early diagnosis is essential for the correction of ectopically erupting canines, it is difficult to determine whether the condition of a canine is within acceptable normal limits, particularly in children aged 10 years or younger. The purpose of the present study was to ascertain the appropriate time for a preventive procedures, such as extraction of the predecessor, in order to avert impaction of maxillary canines. Orthopantomograms of 225 normal children without dental anomalies were examined to compare the eruption stages of mandibular and maxillary canines. Sixty-four patients with 68 unerupted and/or impacted maxillary canines were examined. In normal children, mandibular canines exhibited earlier movement toward oral emergence than maxillary canines on the same side. This tendency was particularly prominent after exfoliation of the mandibular primary canine. In contrast, nearly half of the patients with anomalies were treated before oral emergence of the mandibular canine through simple procedures such as extraction of the primary canine or exposure of the affected canine. The present findings may provide a useful supplemental rule for early diagnosis and aid in decisions whether to treat ectopically erupting maxillary canines, particularly when the anomaly is obscure.

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Ameloblastin is one of the extracellular matrix proteins in tooth enamel and may be responsible for autosomal amelogenesis imperfecta (AI), since it plays a significant role in enamel crystal growth. We investigated polymorphisms of the human ameloblastin gene by polymerase chain reaction, DNA sequencing and single-strand conformational polymorphism (SSCP) analysis using genomic DNA from 50 Japanese subjects with sound dentition. One single sequential trinucleotide deletion and 3 single-nucleotide polymorphisms (SNPs) were identified in the translated region. The nucleotide deletion results in the lack of an amino acid residue and 2 of the SNPs cause nonsynonymous substitutions of amino acid residues. These results provide important background information for the investigation of autosomal AI in Japanese patients.

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Purpose: The purpose of the present study was to investigate the non-nutritive sucking habits of 18-month-old and 42-month-old children in order to determine the best method of advice to stop sucking habits.
Method: We examined the present situation of oral habits, the time of commencement and the time of discontinuation of the habits, the condition of occlusion, and the nursing behavior during the first 3 months from birth in the subjects.
Results: The incidences of finger sucking and pacifier sucking habits in the 18-month-old children were 25.6% and 16.9%, respectively, and the incidences of the habits in the 42-month-old children were 27.2% and 16.8%, respectively. Most cases of the finger sucking habit continued until after 3 years of age, but the pacifier sucking habit was discontinued before 42 months of age. Open bite or maxillary protrusion was found in 70.7% of the 42-month-old children with persistent non-nutritive sucking habits but in only 6.8% of the 42-month-old participating children who had broken their sucking habits. We examined the correlation between non-nutritive sucking habits and nursing behavior. The incidence of oral habits was significantly higher in bottle-fed children than in breast-fed children. Pacifier sucking was more prevalent in children with a short breast feeding duration than in children with a normal feeding duration.
Conclusion: The incidence of finger sucking is higher than that of pacifier sucking in Japan. Malocclusion caused by a sucking habit is more frequent in pacifier suckers than in finger suckers. The incidence of oral habits is higher in bottle-fed children than in breast-fed children.

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Cleft lip with palate is a widespread disfiguring birth defect of complex and poorly understood etiology. The A/WySn mice are good models with which to study the genetic factors of cleft. Our previous study of mated the A/WySn and C3H/He strains found that cleft lip with palate occurred due to cortisone exposure in both the A/WySn and N₂ backcross mice, but not in the C3H/He and F₁ hybrid mice. These findings suggested that autosomal recessive genetic factors cause cleft lip with palate in the A/WySn strain of mice. Interval mapping should identify a candidate chromosome and the region that included the candidate gene(s) causing cleft lip with palate. The present study investigated informative DNA markers for interval mapping. We used 136 Mit (Massachusetts Institute of Technology) markers to amplify target DNA of A/WySn, C3H/He and F₁ hybrid mice by PCR. Amplified DNA products were detected by direct gel analysis. We determined 82 informative markers that were distributed throughout the autosomal chromosome and which could detect polymorphisms between the A/WySn and C3H/He on gel. These results suggest that it is possible to perform the interval mapping for searching candidate chromosome including the loci responsible for cleft lip with palate in A/WySn mice using determined 82 markers.

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Predicting the host genetic factors influencing dental caries susceptibility is important to developing preventive strategies in individuals. In this study, Quantitative Trait Locus (QTL) analysis was used to identify the candidate regions for gene(s) influencing initial dental caries susceptibility in mice, and that performed on genetic crosses of BALB/cJ and C3H/HeJ mice. Two significant QTLs on chromosomes 7 and 11 and five suggestive QTLs on chromosomes 3, 8, 16 and 17 were detected. Around the region 50 cM on Chromosome 7 and 46 cM on chromosome 11, the likelihood ratio statistic (LRS) scores showed higher than significant levels. Around 52.5 cM on chromosome 3, 38.4 cM on chromosome 8, 38.0 cM on chromosome 16, and 6.5 cM and 44.5 cM on chromosome 17, LRS scores showed higher than suggestive levels. Based on these results, it is suggested that the candidate gene(s) responsible for dental caries are located in the specified regions of six chromosomes, chromosomes 7 and 11 in particular are associated with initial dental caries.

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We investigated how child patients take in information from a dentist’s face and whether there is any age difference in the way of scanning the face. For this purpose, we used a non-contact type of eye movement measuring apparatus tradenamed FreeView^® and an upright photograph of a male dentist’s face as the test image. The subjects consisted of a total of 90 children between the ages of 2 years 11 months and 12 years 11 months. The subjects were divided into three age groups-group A (below 7 years), group B (7-9 years) and group C (10 years or above), and their eye movements were measured and analyzed. Our findings are as follows.
1. The saccadic movements to the background of the photo and the fixation points in the background decreased most in group C, followed by group B and group A, in that order.
2. The overlapping of saccadic movements to the features of the face (the eyes, nose and mouth) was remarkably in all age groups. However, the subjects did not scan the whole of the appearance of the face (the hair, forehead, cheeks, ears and chin).
3. The fixation points on the appearance of the face were unevenly distributed. Many fixation points were found close to the features of the face. This peculiarity was common to all the groups.
4. The fixation points on the features of the face increased most in group C, followed by group B and group A, in that order.

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The aims of this study were to investigate the condition of dental caries in 1-4 years old Japanese children with cleft lip and/or palate, and also to examine the relationships between age, location of the cleft, oral health behavior of cleft children and the incidence of dental caries. The study was carried out through a dental examination of a sample of children and a questionnaire to their parents which included questions about infant feeding practices, frequency of consumption of specific drinks and children’s frequency of tooth brushing. A sample of 116, 1-4 years old Japanese children (58 boys and 58 girls) with oral clefts referred to the Department of Pediatric Dentistry Clinic, Showa University, after receiving surgical treatment, participated in this study. Results indicated that the prevalence of caries in cleft children was related to patient age, location of clefts and oral health behavior. A higher level of dental caries was recognized in children with cleft lip and alveolus/palate than in those with cleft lip alone. Incidence of caries increased with patient age. Children who had been fed in a determined time were less affected than those who had been fed at will. Incidence of caries was also high in the children who ingested drinks with sugar than in those who did not. The results of this study suggest that it is important to improve the oral health behavior of cleft children to minimize the risk of caries. Moreover, children with clefts and their parents should as early as possible undergo a preventive program to ensure preservation of primary dentition.

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The aim of this study was to determine the presence of Streptococcus mutans or Streptococcus sobrinus in Cariostat-inoculated plaque samples obtained from Japanese mother-child pairs through a conventional PCR technique and to establish the presence of these bacteria and caries risk. Oral examination and caries risk assessment using the Cariostat^® were carried out on 168 children, aged 6-31 months, and their mothers. The presence of S.mutans and S.sobrinus in Cariostat-inoculated plaque samples was checked through PCR and tested for relevance with caries risk. A significant correlation (P < 0.001) was found between caries risk of mothers and presence of S.mutans or S.sobrinus in plaque samples from their children in the 19-31-month-old age range. However, no significant relationship found between the presence of either strain in the plaque of younger children (6-18 months) and caries risk of mothers. Likewise, high caries risk was seen in 49.1% of the 19-31-month-old children of high-risk mothers (P < 0.001) and 27% of the 6-18-month-old children of high-risk mothers (P < 0.05). The effectiveness of the Cariostat method for prediction of caries risk can be improved by detecting the presence of S.mutans and S.sobrinus in plaque samples obtained from mothers and their children through conventional PCR techniques.

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This simulation study was carried out to analyze and evaluate Cariostat-inoculated samples through a conventional PCR protocol specific for Streptococcus mutans strains and also for the purpose of establishing acceptable storage conditions for Cariostat-inoculated samples in cases in which optimal storage conditions are not feasible. A reference strain of Streptococcus mutans (ATCC 25175) was used in the study. The samples were subjected to different inoculation, incubation and storage conditions, and bacterial viability was checked through a conventional PCR technique and by assessment of colony growth on different agar media. Band detection of all samples incubated for even up to 120 hours at 37°C was still possible, indicating less DNA degradation. Samples stored at -20°C yielded results closest to those of samples incubated normally (without storage), followed by samples stored at 4°C and then samples stored at room temperature. The difference in these results, however did not influence the quality of DNA to an unsatisfactory level. For bacterial viability through agar plating, even if there were no more viable growth on the plates, band detection from strains inoculated and stored in Cariostat was still possible. From these results, we conclude that samples stored under various conditions can be further analyzed using DNA extraction protocols for conventional qualitative PCR amplification.

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The aim of the study was to evaluate caries increment in combination with a caries activity test (CAT21 Test) and a salivary buffer test (CAT21 Buf Test)—to predict future caries activity in Mongolian preschool children living in Ulaanbaatar City. The effectiveness of combining both tests and deft (decayed, extracted, filled teeth) means was also investigated. The caries prevalence in subjects was 94%, and deft mean value was 6.8. The caries increment after one year was 2.3 teeth. From the distribution of CAT21 Test scores a low risk was found in 38.6% and high risk in 61.4% of the examined children. From the CAT21 Buf Test scores, the high risk (lower buffer capacity) was found in 79.8% of the examined children. When the combination CAT21 Test and CAT21 Buf Test scores were divided into four groups (low-low/low-high/high-low/high-high), the mean def-teeth showed a significant difference among the four groups (ANOVA P < 0.001). One year after the caries increment was evaluated in combination with the CAT21 Test scores and CAT21 Buf Test scores, the low-low risk group showed the lowest mean def-teeth. On the other hand, the high-high risk group showed the highest mean def-tooth (ANOVA P < 0.05). Based on these results, the CAT21 Test and CAT21 Buf Test are useful for clinical application of preschool children in predicting future caries activity. Furthermore, when the CAT21 Test and the CAT21 Buf Test were combined, a higher correlation was shown with the caries status.

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This study was conducted to investigate the relationship between results of a salivary buffer test (CAT21 Buf Test) and caries status in 507 preschool children, who were 4-6 years old in Ulaanbaatar City, Mongolia. The prevalence of caries in the preschool children was 96.1%, and the mean deft and d teeth were 8.1 and 7.2, respectively. The mean CAT21 Buf Test score was 53.3% for low risk (high buffer capacity) and 46.7% for high risk (low buffer capacity). When salivary buffer score was divided into two groups (high risk, low risk), mean deft differed a significantly between the two groups (ANOVA P < 0.001). The high risk group had a mean deft higher than that of the low risk group. These results suggest that the CAT21 Buf Test is useful for clinical application in children. Furthermore, when the CAT21 Buf Test score was higher, a higher correlation was shown with caries status.

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The relationship between the development of children’s bodies and gravity center movement was studied. The subjects of this study were 61 children (30 boys, 31 girls) at nursery school. Foot-sole-prints were obtained using a stamp method and presence of foot arch formation was determined. The first measurement was taken in May 2003 and the second measurement was 6 months later. The children’s physical functions were measured including standing height, body weight and foot length. In addition, the distance and the area of center of gravity movement when the subjects had their eyes opened and eyes closed were measured with automatic attitude analytical devices. Occlusal abilities were measured including occlusal contact area, average pressure and occlusal force with the Dental Prescale^®. The male group showed a significantly wider occlusal contact area and a stronger occlusal force than the female group. A significant positive correlation was found between body height and occlusal contact area. A negative correlation was found between contact area and distance of BCG. A significant negative correlation was found between contact area and area of BCG. A significant difference was found between the eyes opened and eyes closed groups in the center of gravity movement for both children with formed foot arches and those without. The center of gravity movement of the foot arch formed group was less than that of the unformed group. A significant difference was found between the formed foot arch group and unformed foot arch group with regard to the improvement in gravity center movement based on the change in results from the first measurement to the second.

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Previous studies using a sortase-deficient mutant (SrtA^- mutant) of Streptococcus mutans have demonstrated that the sortase (SrtA) catalyzes cell wall anchoring of the surface protein antigen PAc, a dextranase and a glucan-binding protein C. In this study, cell wall anchoring of a wall-associated protein antigen A (WapA) and an exo-β-D-fructosidase (FruA) in S.mutans was examined by Western blot analysis with a specific antiserum. In the SrtA^- mutant, FruA and WapA were not bound to the cell wall but were secreted into the culture supernatant. In contrast, in the wild type, both proteins were associated with the cell wall of S.mutans. Biological properties of the SrtA^- mutant were examined by determination of fructan fermentation and adherence to a smooth surface. Both the SrtA^- mutant and the wild type retained the ability to ferment levan. In addition, adherence to a smooth surface of the SrtA^- mutant was as extensive as that of the wild-type 109c when sucrose was present. However, in the absence of sucrose, the adhesion of the SrtA^- mutant remarkably decreased as compared with that of the wild type. These results suggest that SrtA catalyzes anchoring of WapA and FruA to the cell wall in S.mutans and that surface proteins anchored by SrtA are involved in the initial adhesion of S.mutans to smooth surface. In addition, it was shown that both cell wall-anchored and extracellular FruA are related to the degradation of extracellular fructan as a nutrient source.

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Chronic benign neutropenia is seen in children and is usually detected when repeated occurrence of infectious diseases such as acute otitis media, gastroenteritis, tonsillitis and skin infection, are observed. It is rarely diagnosed as a result of detection of oral lesions. A case of chronic benign neutropenia diagnosed during evaluation of severe stomatitis in a 20-month-old Japanese girl is described in this paper. In order to establish a treatment plan, we examined a dental plaque sample by PCR method, but found no specific causal bacteria. When pediatric dentists encounter repeated gingivitis or stomatitis, the possibility of hematologic disease should be considered.

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We treated an unusual case of internal resorption of the maxillary left lateral incisor seen in a 15-year-old female. The patient was referred to our clinic complaining of repeated cold pain and spontaneous pain in the maxillary left lateral incisor region. An intraoral examination revealed that the tooth was a microdont with a large tubercle, with a pink spot observed in the mesio-palatal area, while radiograph revealed an unusual radiolucent lesion in the cervical area of the affected tooth. Our diagnosis was internal resorption and the affected tooth symptoms ceased after a pulpectomy was performed. Over the next 3 years, periodical examinations performed at 3-month intervals did not reveal further resorption.

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Sialolithiasis is a disorder encountered by oral surgeons that is rarely seen in children, although it is rather common in adults. Most sialolith found in children are smaller than 5 mm in diameter, and the majority of reported cases have been treated by surgically. We report a 9-year-old boy with a sialolith that measured 12×3.5×3 mm, which had developed in Wharton’s duct and was then spontaneously passed.

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