Children often suffer dental injuries when playing soccer. The purpose of this study was to investigate the lay people knowledge and attitudes of parents and coaches regarding the emergency treatment of traumatized teeth, in particularly avulsed teeth, and the use of mouthguards. A questionnaire regarding common dental injuries, the replantation of avulsed teeth due to trauma, and mouthguards was submitted to 86 parents whose children were members of soccer teams and to 19 coaches. The following results were obtained. Although a statistically significant difference between the parents and the coaches was not recognized in the reply ratios for all the questionnaire, the ratio of positive answer of the coaches showed a lower tendency than the ratio of the parents regarding items relevant to tooth replantation. Only 9.3% of the parents and none of the coaches had ever been given advice concerning sports-induced dental injuries. On the other hand,65.1% of the parents and 84.2% of the coaches expressed a desire to attend courses regarding dental injuries.
As to the replantation of an avulsed tooth,74.4% of the pa rents and 85.2% of the coaches did not know that avulsed teeth could be replanted, and 75.6% of the parents and 94.7% of the coaches did not know that milk is a better transportation medium for an avulsed tooth. Fewer than 10.5% of the respondents knew that it is best to return an avulsed tooth into the alveolar socket by themselves as soon as possible. As to mouthguards, although 81.4% of the parents and 89.5% of the coaches were aware of the existence of mouthguards, only 35.7% of the parents and 41.2% of the coaches were prepered to require the use of mouthguards for their children while participating in sports. The above results suggest that it is essential to emphasize, especially to coaches, as well as to parents, the possibility of the replantation of an avulsed tooth due to trauma, the use of milk to preserve an avulsed tooth, and the use of a mouthguard, as part of their concern for dental injuries suffered while engaged in sports.

View full abstract

To investigate the correlations of the results of an investigation of functional development with the level of adaptability to dental Treatment among children aged 3 years, development investigation and an overall assessment of the level of adaptability of the children to dental treatment were conducted among 35 children (18 boys and 17 girls) aged 3 years who visited to the Dental Clinic A in Tokyo. The following results were obtained.1. Among the children who showed a high level of adaptability to dental treatment, the percentage of development investigated items for which the developmental quotient was below 100 was low.2. The items to be investigated correlated with the level of adaptability to dental treatment included “basic habits”, “personal relations” and “speech”.3. The children were divided into a “non-adapting group”, “adapting group” and “highly adapting group” based on overall judgment of the adaptability level and differences in the mean developmental quotient for development to be investigated items among the groups were investigated. The index for “movement (exercise)” was significant higher in “the highly adapting group” than in “the adapting group”. The index for “personal relations” was significant higher in “the highly adapting group” than in “the non-adapting group”. The index for “speech” was significant higher in “the accommodating group” than in “the non-adapting group”. All of the above-described research observations indicated that the development investigation provides materials for making judgments which are useful for predicting the adaptability level of children to dental treatment.

View full abstract

Our aim was to investigate, in combination with histomorphology and immunohistochemistry, the development and disintegration of Hertwig's epithelial root sheath (HERS) and associated phenotypic alterations throughout molar root formation in mice. ICR mice,3 through 28 days-old, were used and serial sagittal sections were prepared from the lower first molars. The development of HERS began with the formation of a bilayered extension of the inner and outer dental epithelium from the cervical loop of the enamel organ. The epithelial double layer continued to grow in an apical direction outlining the shape of the future root of the tooth. Through FGF signals HERS cells mediated the differentiation of dental papilla cells into dentin-secreting odontoblasts. HERS proliferation rates did not match the rate of odontoblast proliferation or root elongation, resulting in the separation at the cervical region from the coronal enamel epithelium and the fenestration or disintegration of the epithelial sheath Structure attached to the root dentin. The disintegration of HERS allowed for mesenchymal cells of the dental follicle to come in contact with the outer dentin surface. HERS-derived epithelial cells proved to have diverse rates: migration away from the root surface and incorporation into the cementum. Some of the migrated epithelial cells remained intact as the rests of Malasses in the periodontium, whereas the rest of the migrated cells appeared to undergo epithelial-mesenchymal transformation. The present study using ssDNA antibodies further proved that only a few or some HERS cells underwent apoptosis or cell death during root formation. The results obtained support the theory that HERS acts as a barrier between dental papillae and dental follicle and a guide for root elongation accompanying harmonious root dentinogenesis and cementogenesis. In this sense, the disruption of HERS appears to be a key event during early root formation and eruption.

View full abstract

The purpose of this study was to investigate the effects of calcium carbonate (CaCO₃) on the mlneralization ability of human dental pulp (HDP) cells. HDP cells were treated with 1mM,100μM,10μM and 1μM of CaCO3 for up to 12 days. Non-treated cells served as a control. The cytotoxicity effeet on HDP cells were not detected by treatment with each concentration of CaCO₃. The cell productivity of HDP cells was highest in cultures treated with 10μM-CaCO₃ group. We compared the alka-, line phosphatase (ALP) staining and ALP activity of treatment with each concentration of the CaCO₃groups and control. A larger number of the 10μM-CaCO₃ groups showed positive with ALP staining than other groups. The ALP activity was also highest in cultures treated with 10μM in the CaCO3groups. These results suggested that the mineralization ability of HDP cells was enhanced by treatment with 10μM in the CaCO3 groups.

View full abstract

We have reviewed the records of 114 patients receiving minor surgical procedures as outpatients in the department of Pediatric Dentistry in Kyushu University Dental Hospital from 2003 to 2006.
The mean of number of outpatients with minor surgical procedures in our clinic was about 30 per year, and the male to females ratio was 2: 1. The number of procedures was follows. The extraction of impacted supernumerary teeth accounted for 60 percent of the total, followed by exposure of impacted permanent teeth, application of traction and extraction.
Regarding extraction of impacted excessive teeth, the number of impacted supernumerary teeth was one, the while direction of the dental crown was inverted, and the impacted site was the palatal side in the majority of the cases. Average surgical time was about 40 minutes.
We classified the position of The impacted supernumerary teeth using panorama X-ray films. This classification was useful for the determination of difficulty level of the extraction. The preoperative examination, including blood sampling was effective in assessment of the reaction of the patients before surgery.

View full abstract

We have been conducting a dental examination program for children (ages 3-5 years) at four preschools in S Village since 1986. The prevalence of tooth decay among 3-year-olds was 77.1% in 1986, and rose to 77.4% in 1994. Starting in 1996, we began providing dental examinations and fluoride treatment three times a year rather than twice. To examine the effects of this change, we conducted a survey of tooth decay for three years from 2002 to 2004 and compared the results to figures from 1986 and 1994. We also conducted a questionnaire-based survey of lifestyle habits and used odds comparison to rank the items that will require greater attention and education in the future. The results showed that the percentage of children with decayed and filled teeth (df rate) had decreased among all age groups, from 3- to 5-year-olds, in 2003 and 2004 compared to 2002. The df rate was also down from 1986 and 1994, when dental examinations and fluoride treatment were only given twice a year. However, among the 32 children who were 3 years old in 2002 and who were given dental examinations and fluoride treatments in the subsequent three years, the df rate was 53.1%. That rate increased to 68.8% one year later, when the children were 4 years old and to 71.9% again after two years, when the children were 5 years old. The questionnaire-based survey showed that the answers to two questions,“Do you drink a lot of juice or soft drinks?” and“Do you chew a lot of gum or eat a lot of chocolate or caramel?”had a risk rate o f 1% and 5%, respectively, and that these factors correlated to the presence of tooth decay. The odds ratios were 6.07 and 3.52, respectively, indicating that improving dental health at the day care centers located near this school requires concentrated guidance regarding these two components of the eating habits of children, respectively. This shows the necessity for having primary care dentistry for children to prevent tooth decay and shows the importance of promoting community-based oral hygiene instruction.

View full abstract

Pharmaceutical Sciences Behavior Oral Pediatric Dentistry (Director: Tsutomu Shimono)**Health Care Products Laboratory, KAO Corporation (Director: Toshiyuki Suzuki)Patients found with initial dental caries (white spots) under the recall system in The Pediatric Dental Clinic of Okayama Medical and Dental School and Hospital (14 Infants involving 37 teeth) were monitored under the special recall program using dual component dentifrice. This recall was undertaken 3 times.
The findings are as follows:
1. At the start of the program, The average age of the patients was 11 years 10 months. The average Cariostat®was 1.8. Their teeth were all anterior teeth.
2. To evaluate the effect of the program, we used the light-induced fluorescence method, and picked up an area of initial caries and a luminance rate of initial caries. Area of the initial caries signifies the width of the initial caries. And at the time immediately before beginning, the average of it was 7.4mm². As the program, the area of initial caries decreased. At the area, there was a significant difference between the time of before beginning and the first recall, between the time before beginning and the second recall, between the time before beginning and the third recall.
3. The luminance rate of initial caries means the depth of the initial caries. As the program, the luminance rate of the initial caries decreased. There was however no significant difference between the time before beginning and other the recalls.

View full abstract

The authors previously reported that a lining of titanium oxide liquid between a dentine surface and the tip of a laser apparatus was effective for removing decalcified dentine using Nd-YAG laser irradiation.
Clinical tests of the Nd-YAG laser with titanium oxide was considered, but, it is quite difficult to retain the liquid on the surfaces of decade enamel and soft dentine during laser irradiation.
The purpose of this study was to evaluate the effectiveness of removing sound dentine and decalcified dentine using Nd-YAG laser irradiation with interposition of titanium oxide paste, because the property of the paste is allows it to remain on the surface of teeth easily during the laser irradiation.
The mounts of removed dentine by interposition in all kinds of the pastes containing 10%,20%,30%,40%,50% titanium oxide were significantly higher than that using paste without titanium oxide as control, and the amount was increased by the dose of titanium oxide.
In clinic, a selective removal of soft dentine is recommended us ing a laser irradiation, that is to say less removal of a sound dentine is required.
Based on the results, it was found that 10% to 20% concentration of titanium oxide paste is available for use in the clinic. The reason that the concentration paste displayed relatively high removal of a decalcified dentine and less removal of a sound dentine.

View full abstract

The purpose of this study was to investigate the causative factors of attrition. The authors analyzed two strains of mice which have different susceptibility to attrition. These mice,21 days old, were divided into 2 groups as follow, the solid standard chow group and the powdered high-cholesterol diet group. Mandibular bones were obtained at 240 days after the start of the experiment. The authors compared the mandibular angle, dentin exposure in the occlusal surface and the volume of saliva between the two strains.
The mandibu lar angles of the solid standard chow group were significantly smaller in the C3H mice than those in the C57 BL/6 mice. The results suggested that the C3H mice might have a stronger occlusal force.
The dentin exposure in occlusal the surface of the powdered high-cholesterol diet group was observed using SEM. The exposure in the C57 BL/6 mice was smooth while on the other hand, that in the C3H mice was rough. It is also thought that there are differences in the tooth substance and the jaw movement between the two strains.
The authors gave medicated p ilocarpine to the mice in the solid standard chow group at 90 days, and measured the volume of the saliva extracted for three minutes. The results showed that the volume was obviously greater in the C3H mice than that in the C57 BL/6 mice, and the possibility of a connection between saliva and tooth attrition was suggested.
In this study, we suggest that tooth attrition is connected with the mandibular angle, tooth substance and jaw movement.

View full abstract

The use of fluoride toothpaste was surveyed using a questionnaire regarding 181 primary school children from 1 st to 6th grade in a primary school near the University Dental Hospital. The purpose of the study was to promote the use of fluoride toothpaste among primary school children. The survey was carried out from June to July,2006 using a questionnaire prepared by the Committee for the Promotion of Fluoride Use of the Japanese Society for Dental Health, and the results were as follows.
1. The rate of fluoride toothpaste usage among all of the children was 82.3%. This result indicates that the rate of fluoride toothpaste usage was 7.7 points lower than the“Kenkou Nippon 21”target figure (more than 90%) proposed by the Ministry of Welfare and Health in 2000. Because of this, we must urge increased usage of fluoride toothpaste.
2. Forty-three percent of the subjects used an amount of toothpaste equivalent to size of the 1/3 of the toothbrush head. Also,43.7% of the subjects rinsed their mouth more than 3 times following toothbrushing.
3. Most of the reasons given for the selection of toothpaste were“for dental caries prevention”.
4. The reasons given by parents for not using toothpaste were“never having used toothpaste”,“cannot brush for a few minutes because of bubbles”.
We concluded that accurate and adequ ate information targeting not only parents but also children is necessary to promote the appropriate use of fluoride toothpaste for prevention of dental caries in children.

View full abstract

We have been studying the site-specificity of dental plaque cariogenecity that may be related to the caries status of associated tooth surfaces. The aim of this study was to clarify the two different sites of acid production in dental plaque by determining the plaque pH curves following sucrose exposure. Two-day plaque samples were collected from the upper-anterior-buccal (UAB) and the lower-anteriorlingual (LAL) in each of the 9 adult subjects. Wet plaque samples were transferred to plastic sticks and immediately put into pre-weighed plastic tubes. The samples were weighed and 0.85% KCl solution (1 mg wet plaque/100μl)was added. A stir bar was then added to the p1astic tubes. A micro pH electrode was then inserted and the pH was determined. After 5 minutes,10% sucrose (1 mg wet plaque/30μl) was added, plaque pH was then measured at 60 different time points (1-60 min), and the plaque pH curves were recorded. After plotting the curves, the area under each curve (AUC) was calculated. Mean pH values were reported as the log of the mean hydrogen ion activity (i. e.,10^-pH), and all statistical comparisons were made based on the hydrogen ion activities. Statistical analyses between 2 different sites were carried out using the Mann-Whitney U test.
The results were as follows.
1. The initial pH (without acid) of plaque in the LAL (mean±S. D.: 7.18±0.36)was significantly higher than in the UAB (6.09±0.37) (p<0.01).
2. The AUC of plaque in the UAB (mean±S. D.: 9,01±6.84(mmol/L⋅min))was significantly larger than the LAL(0,52±0.64(mmoVL⋅min))(p<0.01).
In conclusion, the site-specific acid production, which may reflect the differences in exposure to saliva, plaque in the UAB is more cariogenic than in the LAL.

View full abstract

This article presents a rare case of epulis with hard tissue after the extraction of the natal teeth.
A young Japanese girl was found to have epulis with hard tissue after the extraction of the natal teeth in the anterior mandibular alveolar ridge. The hard tissue was observed at about 2 months of age. The lesion was excised under local anesthesia at the about 8 months of age. Histopathologically, the mucosal elevated lesion shows moderately chronic inflamed fibrous and vasophilic connective tissue covered with parakeratotic stratified squamous epithelium. The hard tissue reveals irregularly and incompletely formed tooth dentine and bony cementum. Enamel and root formation were not observed. These findings suggested that the hard tissue had originated from the developing odontogenic remnant of the extracted natal teeth, which must have remained in the gingival tissues and that the epulis was formed by the response to the irritation after the extraction of the natal teeth.
Management of such a case is based on the clinical findings and due to long term observation, because the hard tissue is noted after the extraction of the natal or neonatal teeth.

View full abstract

Live donor liver transplantation is now a standard treatment for children with terminal-stage liver disease, including congenital biliary atresia, with excellent 1- and 5-year survival ratios. Supernumerary teeth may be encountered by the general dental practitioner as a chance finding on a radiograph or as the cause of an impacted central incisor. The most common supernumerary tooth, which appears in the maxillary midline, is called a mesiodens. Supernumerary teeth in the molar region are rare compared with the anterior region. Treatment depends on the type and position of the supernumerary tooth and on its effect on adjacent teeth.
We report a case of multiple supernumerary teeth in the molar region of mandible after Live donor liver transplantation. The patient was 9-year-old boy. He had a congenital biliary atresia and underwent live-liver transplant surgery at the age of 5. All of his permanent teeth showed brownish pigmentation due to bilirubin. The patient showed a rapid growth of nails, feet, and body height after transplantation. There were no supernumerary teeth in the X-ray examination at age 7. However, total four supernumerary teeth were observed at age of 9. These teeth were extracted surgically. Supernumerary teeth did not show any pigmentation indicating that these were formed after Live donor liver transplantation. This result indicate that we need to have careful X-ray examination of supernumerary teeth after Live donor liver transplantation.

View full abstract

Early treatment of malocclusion is often performed with the assumption that it leads to normalized maxillofacial growth and development, removes any dysfunction caused by the malocclusion, and satisfies the demands of patients and their parents. However, it is not possible to use orthodontic appliances in very young infants. In these cases, it may be possible to initiate orthodontic movements with intermittent force applied by the parents. We treated a female infant (1.5 years old) who had anterior cross bite in her primary dentition. Her parents were instructed to press a wooden spatula against the lingual side of her maxillary anterior left incisors for 3 sets of 3 seconds with 2 seconds intervals 50times per day. As a result of this wooden spatula exercise, her cross bite improved in five weeks. The wooden spatula exercises were then terminated, and her maxillary arch form corrected itself in accordance with her maxillofacial growth and development. Normal maximal intercuspal position and anterior occlusion were retained 26 weeks after initiation of the exercises. Although early orthodontic treatment of malocclusion in the primary dentition remains controversial, our results indicate that early treatment of anterior cross bite in primary dentition can lead to normalized growth and development of the maxillofacial morphology.

View full abstract