The prospect of dental treatment causes many young patients to be anxious and/or afraid. Because it is helpful to know in advance how much anxiety a child is experiencing, we have devised a test in which the child places dolls in a miniature dental office. We used this model to study 48 children, aged three to five years, who visited our paediatric dental office. We prepared a doll-house-sized model of a dental office with a dental chair, a dentist, and dental hygienist. We asked children to place two dolls, one a self-doll and the other a parent/guardian-doll at a location of their choosing in the model clinic. The positions children chose to place the dolls helped us to gauge the anxiety they were experiencing as they anticipated dental treatment. The majority of children we tested were not anxious, and they placed the self-doll in the dental chair. In contrast, we observed that many children who did not place the self-doll on the dental chair were uncooperative during subsequent dental treatment. Thus, our doll-placement test is a valuable predictor of the anxiety of children who will receive dental treatment. Although how children placed the parent/guardian-doll also provided useful information, we gained the most valuable information from whether or not the child put the self-doll on the dental chair.

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Although occlusal indices have been useful in research, audit, practice management, and quality assurance in clinical orthodontics, complexity of orthodontic cases had not been easy to assess for a long time in clinical practice. This pilot study aimed at assessing the orthodontic treatment need and complexity in a referral orthodontic centre in Nigeria. A retrospective analysis of 56 pre-treatment study models randomly selected from the orthodontic model collection of the University College Hospital, Ibadan, Nigeria was carried out without any bias for age or gender. The index of Complexity, Outcome and Need (ICON) was used as the outcome measure. Descriptive statistics were employed in the data analysis. Forty-seven (83.9%) of the sample needed treatment. Thirty-four (60.7%) cases were classified as difficult or very difficult. Only 1 (1.8%) and 13(23.2%) belonged to the easy and mild categories, respectively. The overall mean ICON score was 67.4±19.6 SD (range 25-104). Considerable proportions of these referred orthodontic cases in Nigeria needed treatment and had treatment complexity comparable to the Caucasians.

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We report the newly developed Micro-CT, which allows us to observe the individual animal over a long experimental period and to compare changes in pulp tissue in relation to growth and aging without considering individual differences. Further, we used pathological examination to prove similar the result observing from Micro-CT. We have examined wound healing of teeth after pulpotomy in rats, and could clearly observe histopathological changes in the affected teeth and the absorption of temporary filling material and pulp capping agents. In cases with breakage of the dental crown, the CT images agreed with the pathological observations, and it was possible to estimate the time of breakage. In vivo Micro-CT is possible to apply in continuous recording of small experimental animals, such as rats, under anesthesia and the result is sufficiently high. High-quality image was obtained in of the entire head region of the rat. It was suggested that this method can be used for long-term continuous observation of changes in the teeth conditions after pulpotomy in experimental animals. We report the newly developed Micro-CT, which allows us to observe the individual animal over a long experimental period and to compare changes in pulp tissue in relation to growth and aging without considering individual differences.

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OBJECTIVE: The recovery of tooth enamel after acid etching was examined in vitro using enamel powder in order to maximize the contact surface area. METHODS: The weight of the powder decreased due to acid etching and then increased when the powder was exposed to a calcifying solution. The increase in weight was due to the formation of needle like crystals. According to thermal gravimetric analysis, the newly formed enamel layer was very stable, and was suggested to be apatite by X-ray diffraction and FT-Raman analysis. There was no distinct difference between the newly formed layer and the original tooth in terms of composite X-ray image (CaKα and PKα). The new layer appeared to be a crystallized extension of the tooth enamel, as determined from SEM observations. However, the outer layer of tooth enamel was damaged by acid etching, and the crystallization had deteriorated 48 hours later when compared with that of a non-etched sample. On the other hand, we were unable to confirm the effectiveness of the recovery. From these results, the recovery of damage caused by acid etching cannot be expected when a tooth is exposed to a calcifying solution. However, the finding demonstrated that the crystallized layer was apatite.

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In this study, we focused on the relationship between the morphological features of the articular eminence and the presence of the anterior disc displacement on MR image in youngsters. We classified the morphology of the articular eminence into four categories, flattened, sigmoid, box and deformed on MR image. The results of this study indicated that morphological features of the articular eminence on serial MR images were related to the articular disc configuration, which were the presence of the anterior disc displacement in the intercuspal position, the levels of the anteriorly displaced disc in the intercuspal position and the presence of the reductions of the anteriorly displaced disc in the maximum opening mouth position. There were statistically significant differences in the distribution of the morphology of the articular eminence between normal disc position and anterior disc displacement in all of three sagittal planes. There were statistically significant differences in the morphology of the articular eminence among the levels of the anteriorly displaced disc in central and lateral planes. There was statistically significant difference in the distribution of the morphology of the articular eminence between presences of reduction of the anteriorly displaced disc in the central plane. We concluded that the morphological feature of the articular eminence continuously changes as dental arch develops in the time with temporal instability of mixed dentition, and seems to have positive correlation to the anterior disc displacement.

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We previously investigated whether dental pulp-derived cells possess similar pluripotency to bone marrow cells, and reported their capacity to differentiate into osteoblasts, as well as the characteristics of the stem cells present in dental pulp. In the present study, we hypothesized that neural stem cells would also exist in rat dental pulp, similar to bone marrow and the brain, and attempted to induce their differentiation into a neural lineage by applying an in vitro study design previously reported to induce differentiation of human bone marrow cells. Before inducing differentiation, we detected cells expressing nestin (Nes), which is known to be a marker for neural stem cells, within primary cultures of rat dental pulp-derived cells, suggesting the existence of neural stem cells in dental pulp. Quantitative analyses of the mRNA and protein expression levels revealed downregulation of both the Nes mRNA and protein levels to about 68.1% and 12.4%, respectively, after the induction of differentiation compared to the corresponding levels before induction. Conversely, the glial fibrillary acidic protein (Gfap) mRNA level was elevated by 1.3-fold after the induction of differentiation compared with the level before induction. The reduced number of Nes-positive cells and decreased Nes mRNA and protein levels after the induction of differentiation may be attributed to differentiation of neural stem cells into a neural lineage. Moreover, the increased number of Gfap-positive cells and increased Gfap mRNA level after the induction of differentiation most likely support their progressive differentiation into a glial cell lineage, since Gfap is a marker that is upregulated in glial cells. Our present data demonstrate the existence of neural stem cells in tissues other than the central nervous system, and may represent a significant step toward providing more diverse and multiple sources of stem cells for future regenerative medicine.

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OBJECTIVES: To assess the degree of plaque, gingivitis and caries in children who either did or did not take part in a regular oral preventive program, thus establishing an overview of the oral health condition of those populations. METHODS: A population of 325 Brazilian children aged 8-12 years old, from two public schools, whose parents granted permission, were divided into two groups according to their school. The main group (G1) consisted of 203 children from the school, which has the preventive program, while the control group (G2) consisted of 122 children from the school without the program. The children were examined clinically by a single examiner to assess plaque and gingival status, as well as caries prevalence in order to assess their oral health status. Data was inserted in SPSS 11.0 and the Mann-Whitney test with a significance level of 5% was used for data analyses of the independent variables, while the Student t test was used for comparison between averages. RESULTS: The mean plaque score and mean gingival bleeding score of G2 were higher than G1 (P < 0.05). Regarding the percentage of caries-free children, it was 31.0% with a mean DMFT + dmft of 2.07 (±2.87) in G1 and 21.3% with a mean DMFT + dmft of 3.03 (±2.79) in G2 (P > 0.05). CONCLUSION: It was concluded that the oral preventive program seemed to demonstrate a satisfactory impact on the oral health condition of the target children when compared to the ones who were not enrolled in a school-based program.

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It is important to know racial differences in the characteristics of the dental arch form from the view point not only of dental interests but also of anthropology. We got an opportunity to investigate the status of oral condition of children living in the Changchum-city, Jilin Province in China. The size and the form of the deciduous dental arch were measured using plaster casts prepared from the impressions taken at the time of oral examination. The same measurement was conducted using the dental plaster cast of the Japanese children and the size and shape of the dental arch were compared between the Japanese and the Chinese children. The subjects were the Chinese children who had the Hellman IIA dentition lining in Changchum-city. The average age of the Chinese children was 9 years and 4 months and that of the Japanese children was 4 years and 1 month. The measurement results showed that the Chinese children were bigger than Japanese children in every measurement items. As for the dental arch form, Japanese children had a U-shaped arch form with wider width in the front part of the dental arch. On the other hand, the Chinese children had a half-circle-shape arch form that the front arch width was not so wide but that of the back was wide.

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Morphometry of the zygomatic arch was obtained using 30 Indian dried skulls at each of Hellman’s dental stages: IIA, IIIA, IIIB, IVA, and VA, for a total of 150 skulls 300 sides. The following conclusions were obtained.
1. Though both the height and length of the zygomatic arch increased at all stages from IIA to VA, the rate of increase of the height indicated a value larger than the length.
2. The zygomaticotemporal suture consisted of the vertical element from the upper margin to the center and the horizontal element from the lower side to the margo inferior during the IIA period. This suture changed to a gradual curve from the upper margin to the margo inferior with the movement of the center and the lower side to the rear during the VA period.
3. The degree of interdigitation of the zygomaticotemporal suture increased from the IIA period to the IIIA and IIIB to IVA.
These findings suggest that the form of the zygomatic arch and the zygomaticotemporal suture showed growth change adjusting to the functional change in mastication with growth.

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Five cases of delayed eruption of the first molars due to immature tooth formation are presented. Three cases involved a teeth in a single quadrant, two of which were the maxillary left region while the other was in the maxillary right region. Both the maxillary left and right regions were affected in one case, and all four molar regions were affected in another case. Dental age was calculated by evaluating the tooth developmental stage in each case, and was compared with chronological age (CA). The mean dental age, excluding the affected molar region (MD), was compared with the dental age of the affected tooth (DA). The CA was more than 1 SD older than the MD in four cases. When we considered the affected molars to be first permanent molars, DA was 1.51-2.43 years younger than MD in all five cases, while DA was approximately 1.07-2.39 years older than MD when the affected molars were considered as second permanent molars. These results indicated that the developmental stages of the affected molars were between that of the first and second molars, and were estimated to have emerged into oral cavity at an age between 9 and 10 years old.

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The caries-preventive effect of fluoride is well known. The widespread use of fluoride-containing toothpastes and mouthrinses has been recommended to reduce dental caries. Many kinds of fluoride-containing toothpastes are available in Japan. The aim of this study was to investigate the current status of fluoride-containing toothpastes on the market in two European countries. Fluoride-containing toothpastes were purchased from retail outlets in Cardiff, United Kingdom, and Frankfurt, Germany. The ingredients labels were studied to determine the type and concentration of fluoride. Most of the toothpastes contained sodium fluoride (56.4%); some contained monofluoroacetic sodium (31.7%), stearyl trihydroxyethyl propylenediamine dihydrofluoride (1.0%), aluminium fluoride (1.0%), stannous fluoride (2.0%), or amine fluoride (5.0%). The concentration of fluoride in these products ranged from 800 to 1,500 ppm.

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