The aim of the study was to determine dental caries prevalence among a representative sample of 12-14 year old school children in Ibadan, Nigeria with a view of determining Restorative Index and Met Need Index of the studied population. Dental caries was diagnosed according to the WHO method. Out of the 577 children in the age group, 65 children (11.2%) had dental caries experience as expressed with the DMFT index. More than 85% of the children were caries free. A mode of one DMFT was the highest score for the children although a 14-year-old pupil had DMFT score of 6. Female children had higher mean DMFT score of 2.03±1.13 compared with 1.78±1.0 for males (P > 0.05). The Restorative Index (RI) and Met Need Index (MNI) for the children were very low as only the 14-year-old children had an RI of 3.45% and MNI of 0.11. Restorative Index reflects the restorative care of those who have suffered the disease and it is measured as a ratio of filled to filled plus decayed teeth percent that is F/F+D percent. Met Need Index is an indication of treatment received by an individual and it is measured by the ratio of the mean missing plus filled teeth to mean decayed, missing and filled teeth that is M+F/DMF. Since cost of management, which may be out of the reach of these children, has been identified as one of the factors militating against their receiving treatment, the result of this study suggest that oral health education with emphasis on correcting snacking habits of school children is desirable.

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To clarify the effects of a vibration stimulus 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 application of the vibration stimulus (referred to as S_pre) and after the application of the vibration stimulus (S_post); 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 the ability of healthy subjects to discriminate between S_pre and S_post during LG inhalation using different test sticks, when the test stick diameter was 9.5 mm (smaller than the reference stick diameter), the rate of mis-estimation (RME) for S_post was significantly larger than that for S_pre (P < 0.05). No significant differences were observed for any other test sticks.
2) In comparing the ability of CP patients to discriminate between S_pre and S_post during LG inhalation using different test sticks, when the test stick diameter was 9.5 mm (smaller than the reference stick diameter), the RME for S_post was significantly smaller than that for S_pre (P < 0.05). No significant differences were observed for any other test sticks.
These results suggest the following: the combination of LG for sedation with vibration stimulus further inhibits neuronal functions at the upper level of the central nervous system in CP patients, compared with cases in which each variable is applied separately, and the combination also inhibits the sustained increase in muscle tonus, which is characteristic of CP patients. LG reduces the activity of γ-motor neurons via the upper level of the central nervous system. In addition, tonic vibration reflex (TVR) develops due to the vibration stimulus, which increases the threshold value of sensitive muscle sensation and decreases the activity of γ-motor neurons, and furthermore decreases the activity of muscle spindles attached to the lower jaw. Consequently, a tendency toward increased ability to discriminate lower-jaw position is observed.

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This study is to compare the fluoride uptake of three fluoride agents and the effect of remineralization on artificial enamel lesions. Eight human third molars were all divided into four slabs. The slabs were randomly assigned to the following four groups: group A (9,040 ppm F, APF gel), group B (968 ppm F, SnF₂ home gel), group C (22,600 ppm F, fluoride varnish, FV) and a control group. After 72-hour demineralizing and 10-day pH-cycling period with the application of corresponding fluorides. The distribution of fluoride and mineral change was analyzed with EPMA and CMR respectively. There was a significant increase in the amount of F uptake after the application of the three fluoride agents compared to the control group. Group A showed an extremely greater F uptake compared to group C and B. The amount of F uptake from group C was greater than that of group B. The three tested groups showed signs of significantly greater amounts of remineralization as compared to the control group. Remineralization of group C was detected to be the greatest, followed by group A and group B, but there was no significant difference in them under statistical analysis. It can be concluded that all of the tested agents were effective in regaining mineral loss. FV may be recommended as a professional topical fluoride. It is as effective, if not more so, as traditionally used APF gel. Also 0.4% SnF₂ home gel is an efficient self-applied topical fluoride for daily use.

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Although studies have identified several genes that are involved in tooth root formation, little is known about the genetics of root fusion. The purpose of the present study was to identify the chromosomal region that includes the candidate gene causing root fusion, using SMXA recombinant inbred (RI) strains of mice. Fusion of the mesial and palatal roots of the upper second molars (M²) was observed in 16 of 21 substrains of SMXA RI mice. The incidence of root fusion of the M² in substrains and parental strains showed a continuous spectrum of distribution between 0 and 85%. In a genome-wide linkage analysis, a high Lod score exceeding the suggestive threshold level was found between D5Mit97 and D5Mit31 on chromosome 5. These findings suggest that a polygenic system with incomplete penetrance is involved in the fusion of roots, and that one of the genes causing root fusion of the M² in mice is located in a distal region on chromosome 5.

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The purpose of this study was to assess the effects of prolonged breast- and bottle-feeding on the growing primary dentition. This longitudinal study was conducted through a survey questionnaire and clinical examination of 592 children from 18 months to 36 months of age. Selected occlusal characteristics were compared among groups of children with different durations of breast- or bottle-feeding. The prevalence of breast-feeding at 18 months, 24 months and 36 months of age was 9.3%, 3.2% and 0.2% respectively. Prevalence of bottle-feeding was 14.4%, 2.9% and 0.7% respectively. Deepbite showed tendencies towards increasing prevalence with increased bottle-feeding duration. One third of the children who continued bottle-feeding at 24 months of age exhibited deepbite. Anterior crossbite were significantly more prevalent among those with continued breast-feeding at 18 months but ceased by 24 months (28.0%) than for that in the habit-free group (11.7%). However, anterior crossbite showed tendencies towards decreasing prevalence with increased breast-feeding duration. The prevalence of anterior crossbite was 6.7% in the children who continued breast-feeding at 24 months of age. However, the study suggests that spontaneous change in the occlusion following feeding discontinuation, although longer-term longitudinal studies are needed to demonstrate such changes directly.

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Brain activation is known to occur in the process of visual recognition, but the details of the mechanism are still unknown. In this study, we examined the behavioral and visual scanning patterns of rats to investigate the effectiveness of visual recognition of a triangle as visual stimulus in the Progressive Relaxation Method. The results indicated no difference in the rats’ residence time between an inverted and upright triangle when the figures were displayed. For the gazing pattern, the rats gazed more at the right side of the inverted triangle (angled upwards to the right) than at the left side (angled upwards to the left). The opposite result was seen for the upright triangle with the rat gazing more at the left than the right side. The cause for this difference in the gazing frequency is in the angulation of the side, angled upwards to the right or left, rather than the location of the side, situated on the left or right. Furthermore, the gazing time for an inverted triangle was longer than that for an upright triangle, clearly indicating the effect of location of the upper-right angled side on the frequency of gazing. These results suggest the possibility of a high level of ease and preference in rats for visual scanning of an inverted triangle and its right side.

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Mutans group streptococci play an important role in the formation of dental caries, while mitis group streptococci are considered to be associated with subacute bacterial endocarditis. Both mitis and salivarius group streptococci, which are early colonizers in the human oral cavity, have an effect on the infection and colonization of mutans streptococci. In the present study, a rapid and exact PCR method to detect those oral streptococci was developed using the 16S-23S ribosomal RNA intergenic spacer gene, which is present between 16S rRNA and 23S rRNA within the RNA operon. The PCR analysis was able to correctly identify mutans and mitis group streptococcal species. Our results indicate that the combined PCR analysis method established in the present study is useful for detecting oral streptococcal species, as well as in clinical applications to predict and prevent dental caries and etiological studies of streptococcal infective endocarditis.

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The aim of this study is construct a systematic classification system of children by their behavior. The study population consisted of 104 children who visited the pediatric dentistry at the Dental Hospital of Tsurumi University for the first time. The behavior of the children was evaluated by the Frankl Behavior Rating Scale and the behavior evaluation score developed by Kurosu. For the classification, k-means and two-step cluster and a large scale clustering method, the Kohonen network were used. The Frankl Behavior Rating Scale and all clusters were statistically significant according to Fisher’s exact tests. Among them, the results using the two-step cluster analysis were well classified for the Frankl Behavior Rating Scale and may seem to be clinically available. Decision analysis to clarify the decision rules for affiliation extracted 5 items such as ‘Moving the body left and right’, ‘Putting hands over the mouth’, ‘Crying softly’, ‘Holding the hands of the dentist’, ‘Closing the eyes’. And these items would be key items to peg uncooperative behavior in clinical practice. By the observation of some of the behavior of the children and using decision tree, systemic decisions can be made for the obscured Frankl Behavior Rating Scale.

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The purpose of this study was to investigate risk behaviors associated with the presence of S.mutans or S.sobrinus and caries activity. The subjects were 448 mother-child pairs who underwent dental health examinations between February 2004 and November 2004 when the children were 18 months old. Caries activity was assessed by the Cariostat test. The presence of S.mutans and S.sobrinus was detected using PCR techniques. Questionnaires regarding risk behaviors were completed by the mothers. A statistically significant correlation was found for the detection of S.mutans and/or S.sobrinus in children and mothers (P < 0.01). High-risk mothers were more likely to have high-risk children (P < 0.001). In children in whom bacteria were detected, breast-feeding was ranked as the most important risk factor (P < 0.01), followed by eating snacks while playing (P < 0.01), getting snacks from neighbors (P < 0.05), being cared for by grandparents (P < 0.05) and pre-chewing of children’s food by mothers (P < 0.05). In children with high caries risk, breast-feeding and pre-chewing were the most important risk factors (P < 0.01), followed by taking meals at irregular intervals and mothers not attending maternity classes (P < 0.05).

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Objectives: To analyze the relationship between caries risk and the presence of S.mutans and S.sobrinus from plaques of pregnant women using the Cariostat method and the polymerase chain reaction (PCR) technique.
Materials and Methods: The subjects consisted of 269 pregnant women who were in their 3rd, 4th or 5th month of pregnancy. The presence of S.mutans and S.sobrinus was assessed from their plaques cultured in the Cariostat medium and assessed by PCR.
Results: The correlation between caries risk scores assessed by the Cariostat method and the presence of S.mutans was statistically significant (P < 0.05). The tendency of positive correlation was found between the presence of S.sobrinus and caries activity.
Conclusion: This study suggested that pregnant women who have high caries activity should be more aware of the possibility of transmission of cariogenic bacteria to their infants.

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I-cell disease is a rare autorecessive metabolic disorder that is classified as one of the lysosomal storage diseases. Gingival enlargement is a representative oral manifestation of patients with I-cell disease. This report describes a case with a satisfactory prognosis after gingivectomy for gingival enlargement accompanying I-cell disease in a 2-year-old boy. The chief complaints were both eating disorders and night terrors accompanied by gingival enlargement of both the maxillary and mandibular alveolar gingivae, especially in the region of the first deciduous molars. Although it was supposed that there were various hazards associated with gingivectomy caused by aortic incompetence, sigmoidal spinal curvature and hypertrophy of the laryngopharynx, gingivectomy with an internal bevel incision was performed under general anesthesia to improve the chief complaints. A piece of the enlarged gingivae dissected during the operation was examined histopathologically, and the histopathological diagnosis was gingival hyperplasia. The patient’s signs and symptoms of the eating disorders and night terrors have improved since the gingivectomy operation. Recurrence of the gingival enlargement has not been identified up to 18 months after the surgery. It is therefore concluded that gingivectomy for gingival enlargement accompanying I-cell disease was effective for this 2-year-old boy.

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Two cases with severe periodontal inflammation in areas of teeth applied with orthodontic bands are presented. Both were diagnosed as acute periodontitis, and removal of the orthodontic bands followed by professional oral hygiene procedures resulted in the recovery to the normal level of periodontal condition. The presence of 10 targeted species of Gram-negative periodontal bacteria in subgingival plaque samples taken from the corresponding teeth, which were not detected in either patient during the period of severe periodontal inflammation, was assessed several times using a polymerase chain reaction method. As the periodontal conditions of the patients improved, these bacteria were identified during the follow-up examination periods. Our results suggest that none of the 10 Gram-negative periodontal bacteria were associated the acute periodontitis at the teeth applied with orthodontic bands.

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We present a case of a triple-X syndrome in a Japanese girl who was treated from 5Y9M to 14Y6M of age at the Pedodontic Clinic of Osaka University Dental Hospital. At the first examination, multiple dental caries were identified, and a pulpectomy and extraction of the affected teeth were carried out. There were no congenitally absent teeth, including third molars, though the development of permanent teeth was approximately 2 years behind chronological age. At 14Y6M, a PCR analysis of 10 putative periodontopathic bacteria was performed, and all 10 species were found in saliva samples. At the same time, an oral examination revealed that the gingival tissues were highly inflamed with an extremely large amount of calculus, suggesting a risk for the early onset of periodontitis.

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