We implemented a caries prevention program in 2 nursery schools located in a small rural town. Seventy-one children aged 1-4 years were followed-up for 2 years. The program included fluoride application, dental check-ups every 3 months, and dental health education for guardians via printed media. As a result, the program was effective in preventing cavities of first molars. Also, caries incidence in primary teeth at nursery school A was considerably lower than that at nursery school B. We. therefore, compared A with B regarding factors associated with dental caries incidence. Concerning dental health behavior, we revealed that the number of guardians that brushed their childrens' teeth every day at nursery school A was higher than that at nursery school B during the term, not at the start of the program. 'Dental plaque deposition', 'presence of mutans streptococci', and irregular toothbrushing by guardians were related to increasing caries incidence at nursery school A but not at B. The frequency of toothbrushing by guardians was correlated with the amount of plaque at nursery school A but not at B. Continuity of 'the frequency of toothbrushing by guardians' was noted during the program in nursery school A, but only for one year in B. The questionnaire on dental health behavior for staff of the nursery schools indicated the lack of information provision regarding dental check-ups and irregular candy consumption in nursery school B. In conclusion, the caries prevention program in the nursery schools was effective for first molars, and we showed that direct dental health education for guardians and staff is needed for caries prevention of primary teeth.

View full abstract

The present study was conducted in order to identify risk factors associated with tooth loss among patients who underwent a long-term maintenance program at dental clinics. Subjects were selected from patients who had received a maintenance program for more than 15 years and made the last dental visit during the 4 months between July and October, 2004, at one of two private dental surgeries in Osaka. Annual tooth loss for each subject was calculated from the difference in tooth number between the first and last visits. The mean age of the 371 subjects in this study was 67.5 years old, and the average length of maintenance, between the base line and the last visit, was 26.6 years. The average annual tooth loss was 0.086 for males and 0.075 for females, not including wisdom teeth. Multiple regression analysis showed that individuals with an older age, fewer teeth, more non-vital teeth, and a periodontal pocket depth of 4mm and over at the first visit, had a higher rate of annual tooth loss. Also, individuals with diabetes mellitus, a smoking habit, and those who made infrequent dental visits had a higher rate. The present study suggested that age, number of teeth, periodontal pocket depth, general health status, and pulpectomy could be risk factors associated with tooth loss in patients of dental surgeries during a long-term maintenance program.

View full abstract

In 2004, we carried out a survey of 610 people who underwent basic physical examinations in Mizuho, (Ohnan-cho), Shimane Prefecture. Subjects completed questionnaires regarding food they could ingest. As an objective evaluation, each subject was given a Gummy (a soft chewy candy) to chew. After 15 seconds, the Gummy was expelled and the pieces counted. The results of these two methods were compared and analyzed. Subjects were divided into four groups depending upon the number of teeth (0, 1-9, 10-19, and 20 or more). Compared to the other three groups, the "10-19" group responded that it could chew the smallest variety of foods. When we put the percentage of people who could choose all foods on the vertical axis and the number of teeth they had on the horizontal axis, the resulting graph was U-shaped. On the other hand, the number of Gummy pieces was the smallest in the "0" group and increased according to the number of teeth. The greatest difference between subjective and objective evaluations was seen in the subjects with the fewest teeth. The Mann Whitney test was used to analyze the subjective evaluation of which foods could and couldn't be chewed based upon the number of Gummy pieces. As the number of teeth decreased, the p value increased, and it became difficult to confirm significance between both valuations. Moreover, even when utilizing multiple regression analysis in which the number of Gummy pieces is the objective variable, the subjective evaluation can be adopted as a valid explanatory variable in the "20 or more" group, but it can't be applied to the "0" group. Therefore, the subjective evaluation became less valid as the number of teeth decreased.

View full abstract

It has been reported that about half of infants and toddlers suck their fingers. This habit affects the development and arrangement of their teeth. The aim of this study was to elucidate factors associated with the onset and cessation of the finger sucking habit by a cross-sectional survey. The subjects were 512 children aged from 36 to 47 months that underwent health examinations at municipal health centers. The prevalence of the sucking habit was 15.8%. As a result of the attribution analysis for the onset of finger sucking, 'siblings also showing a finger sucking habit' and 'rural area' were strongly associated. The odds ratios were 3.05 (p<0.001) and 1.67 (p<0.05), respectively. Regarding the cessation of finger sucking, the attribution analysis showed that 'urban area', 'conceptions of their mothers', and 'breastfeeding for more than 11 months' were related. The odds ratios were 2.56 (p<0.05), 5.00 (p<0.05), and 6.14 (p<0.001), respectively. These results indicate that 'siblings also showing a finger sucking habit' and 'rural area' were the initiating factors for finger sucking, whereas breastfeeding for at least 12 months is important for the cessation of finger sucking.

View full abstract

It is important that fluoride mouth rinsing continues until an appropriate age for caries prevention. During elementary school, upper grade children's realization of autonomous morality arises, and it is thought that children's preferences influence their participation in fluoride mouth rinsing programs. Therefore, we investigated their knowledge of fluoride mouth rinsing and their present participation in the program. Furthermore, we examined improvement in the situation by education. Data were collected by questionnaire surveys for upper grade children from all elementary schools (about 330 children) of a town : Districts A and B in 2003-5. The fluoride mouth rinsing program is performed in all elementary and junior high schools in the town. District B teaches the children about the positive effects of fluoride mouth rinsing, whereas District A does not. In children that participated in the fluoride mouth rinsing programs in Districts A and B during all 4-6 years of schooling, 61.1% of them reported in 2003 that they "did it every time" when questioned about fluoride mouth rinsing. Five factors were related to fluoride mouth rinsing : "school", "grade", "tooth brushing in the morning", "tooth brushing after lunch", and "knowledge of fluoride mouth rinsing's effects". The children who were in 4 th and 5 th grades in the 2003 and in the 4 th grade in the 2004 fluoride mouth rinsing programs showed a tendency to increase in District B, but decrease in District A. Among elementary school upper grade children, only about 60% of them "did it every time" when asked about fluoride mouth rinsing. To increase the number of children who participate in fluoride mouth rinsing, it is suggested that positive education is effective.

View full abstract

Periodontal disease is the most prevalent of all diseases, affecting about 90% of adults around the world. As it is directly associated with tooth loss, effective community programs for the prevention of periodontal disease are essential to achieve a society in which all people have their own natural and functional teeth. In this study, a 14-year community-based program for the prevention of periodontal disease was evaluated. The periodontal disease prevention program was conducted from 1992 to 2005 in association with annual medical health screening in a rural area of Japan. The participants of the program were examined based on the Community Periodontal Index (CPI) and numbers of decayed, filled, and missing teeth, followed by person-to-person toothbrushing instructions. The "Toothpick method" of toothbrushing, indicated for interdental cleaning, was demonstrated intra-orally by dentists or dental students and practiced for about 15 minutes. The brushing method enabled us to easily remove dental plaque and to stimulate gingival tissue in interdental areas, without using dental floss or an interdental brush. The 14-year data were analyzed using a statistical package. A total of 1, 012 adults (297 males and 715 females) participated during the 14 years. The mean age of the subjects calculated each year ranged between 49 and 56 and gradually increased with time. The mean numbers of decayed and missing teeth were reduced from 0.9 to 0.2 and from 3.2 to 1.6, respectively. The mean number of filled teeth was increased from 10.0 to 12.0. The percentage of subjects with a CPI score of 3 or more decreased during the 14 years. In the 14 years, 446 people participated in the program more than once. The percentage of male subjects who participated more than once was significantly lower than that in subjects who participated only once. Participants who joined the program frequently showed a better periodontal status at the final examination. Logistic regression analysis was performed to investigate the association between independent variables including age, sex, numbers of decayed, filled, and missing teeth, and the number of participations in the program, with the presence (CPI score of 3 or 4) or absence (CPI score of 0, 1 or 2) of periodontitis, disclosing that male gender, old age, and a lower frequency of participation increased the risk of periodontitis. These results show that a continual community-based program for the prevention of periodontal disease, including examination and individual toothbrushing instructions with the "Toothpick method", was effective in improving the periodontal condition.

View full abstract

Some social factors, such as the advancement of dental technology and the increase of in-home care, have recently changed the two-year vocational schools and junior colleges for dental hygienists to three-year vocational schools and junior colleges, or to university departments. Therefore, it seems necessary to construct new clinical training methods. The Preventive Dentistry Department in Hiroshima University Hospital has given clinical training to many students of dental hygiene from some schools, and received the last students from a two-year vocational school in the 2005 academic year. Thereafter, the university hospital has been expected to train more educated students and produce better dental hygienists. Thus, it seems urgently necessary to evaluate he present training methods, before the preparation of new methods. This study investigated the self-evaluation of clinical skills by students from a two-year vocational school for dental hygienists, before and after the clinical training at the reventive Dentistry Department in Hiroshima University Hospital in the 2005 academic year. Self-evaluation can be considered as one of the methods of evaluation of clinical training, since better clinical training should produce an improvement in self-evaluation. As a result, the level of self-evaluation of most clinical skills after clinical training was significantly higher than that before training. Therefore, it was suggested that the students were conscious of the effectiveness of the clinical training. The results of this study might be useful as a standard to evaluate new training methods.

View full abstract

On the evening of October 23, 2004, a series of unusually powerful earthquakes ripped through Japan's northwestern Niigata Prefecture, registering at a maximum intensity of 7 on the Japanese seismic scale. In April 2005, the authors visited one of the villages in the quake-devastated district of Chuetsu. With the cooperation of a dental clinic there, a survey was conducted to clarify the state of oral health among villagers who took shelter immediately after the tremor and about 50 days or so afterward, when they were settled into temporary housing units. The survey was participated in by 388 patients of the village clinic. The findings are as follows : 1. The number of times they brushed their teeth decreased for a while following the shock. After they started to live in temporary housing, the frequency of toothbrushing increased compared with that before the quake, with the majority of subjects saying that they brushed their teeth in the same way as before. A little over 10% of the respondents admitted that they performed toothbrushing more half-heartedly than before. 2. For some days following the quake, many subjects rinsed their mouth with mouthwash. More than 80% of them obtained toothbrushes within three days after the earthquake. 3. What they wanted the most among items related to oral hygiene was toothbrushes, which was followed by cups and gargle solution in that order. Although the subjects in the present study were the inhabitants of a small rural community and showed an age bias, we think that the actual facts brought to light regarding toothbrushing and oral health and what is needed before and after such a natural disaster were clarified.

View full abstract