In June 2007, the "Declaration of Promotion of Shokuiku" was announced for parties concerned in dentistry. The declaration emphasizes the importance of promoting Shokuiku activities. An adequate eating manner including tasting and relaxing habits through the five senses must be encouraged by accumulating knowledge and experience. It also indicates that diet becomes sound mental and physical nourishment with the aid of obtained knowledge and experience of foods and eating manner, resulting in a rich humanity.

The "Eating manner" as the core of the Shokuiku promoted by the field of dentistry usually develops in response to the growth of oral region during infantile and schoolchild periods. The oral health during these periods is generally taken under the charge of pediatric dentists. Therefore, pedodontists are required to share the promotion of Shokuiku, mainly 'the eating manner,' for both children and their parents during functional development including chewing, drinking and tasting habits.

Shokuiku in childhood is desirable, which should begin with the manner of eating, to encourage adequate masticating habits for development of the five senses and/or an eating manner such as tasting and relaxing, in accordance with the degree of growth and development during individual stages of life including conventional so-called mother and child health as well as school health periods.

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In recent years, the use of lasers for cavity preparation has been attracting attention in dental treatment, however, there are very few reports regarding children's psychological evaluation in regard to the treatment of primary teeth caries. Therefore, we evaluated the level of pain and discomfort in the treatment of primary teeth caries using an Er:YAG laser and assessed the effectiveness of using an Er:YAG laser on pediatric patients.

The subjects comprised of 26 pediatric patients ranging from 2 to 10 years of age (11 boys, 15girls, mean age: 4.9 years) who visited the Pediatric Dental Clinic at Nippon Dental University Hospital. The pediatric patients were diagnosed to have dental caries in a dentin lesion, in whom we performed composite resin restoration using the Er:YAG laser on 34 primary teeth. For the evaluation of pain and discomfort, we used the Face Scale (FS) with six grades (0−5), and the dentist asked the pediatric patients about pain and discomfort during the use of the Er:YAG laser based on the FS immediately after the treatment.

As a result, the mean for pain and discomfort were 0.7±0.9 and 0.7±1.0, respectively, wherein pediatric patients felt very little pain or discomfort. In comparing boy and girl pediatric patients, the girl patients exhibited a slightly higher value of pain than the boy patients, however, no significant difference was observed. In a comparison of the maxillary primary teeth and mandibular primary teeth and the primary anterior teeth and molars, no significant difference was observed in regard to pain and discomfort. In response to the question as to whether they would like to have the an Er:YAG laser used for subsequent dental treatments, 81% of the pediatric patients answered "yes."

These results may suggest that the treatment of primary teeth caries using an Er:YAG laser is effective for pediatric patients.

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Laser irradiation has been widely used in dental clinics for cutting and evaporating hard tissue. However, there are only a few studies on the crystallographic change of the enamel caused by the heat evolved during laser irradiation. We investigated the crystallographic change of bovine enamel powder by CO₂ laser irradiation at various energy levels using Fourier-transform infrared absorption spectroscopy (FT-IR), X-ray diffraction(XRD) and scanning electron microscopy(SEM). We also performed thermo gravimetric analysis (TG) of enamel powder.

The following results were obtained;

1. Average temperature rises were estimated at 800℃ or more, 1000℃, 1200℃ and 1400℃ or more when the CO₂ laser was irradiated at 1W, 3W, 5W and 7W of output levels, respectively. However, the maximum temperature was probably even higher around the focus point of the irradiation area at each output level.

2. HAP of the bovine enamel seemed to be completely melted over 3W of the laser output level and α-TCP and TTCP re-crystallized during cooling after the irradiation.

3. SEM observation clearly showed spherical particles of various sizes, which were formed by the melting of bovine enamel during the laser irradiation. The surface of the spherical particles become smoother at the higher output level over 5W.

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For sophisticated instruction of dental educators, it is essential to comprehend educational contents for pre-clinical practice of pediatric dentistry among all dental schools in Japan. Because there are no publications on this problem, this questionnaire survey was conducted to investigate it. This study provides an actual situation of the pre-clinical practice of pediatric dentistry at all dental schools in Japan.

The results were as follows:

1. Rubber-dam installation was most frequently performed on the first molar.

2. Giving tooth brushing instruction to the guardian of the pediatric patient was most frequently per formed with children 3 years of age.

3. Gel was used most frequently for the topical application of fluoride.

4. Pit and fissure sealant was most frequently performed on the first molar.

5. Study model analysis was taught among 17 dental schools. Mixed dentition analysis was learned among 13 dental schools.

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For sophisticated instruction of dental educators, it is essential to establish educational guidelines for pre-clinical practice of pediatric dentistry among all dental schools in Japan. However, there is too little information on this problem. Therefore, with the aim of realizing a good quality of pre-clinical practice, an educational workshop was organized by the Japanese society of pediatric dentistry. This workshop was held over two days at Hiroshima University in Hiroshima, Japan. Forty-two dental educators from all the dental schools in Japan participated in this workshop. The following 5 topics were discussed : rubber-dam, oral hygiene counseling for parents/guardians, fluoride therapy, fissure sealant and space maintenance and space regaining.

The efforts of this workshop were as follows :

1. This workshop provided useful information about pre-clinical practice of pediatric dentistry of all the dental schools in Japan.

2. All participants understood the ideal and common objectives of instruction of the topics.

3. The bases of educational contents on the topics were discussed and identified.

In conclusion, this article provided on outline of dental education of pediatric dentistry and contributes to a better understanding of the importance of educational guidelines. Continuous interchange of ideas is going to be expected to develop the quality of education and the ability of instruction.

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The aim of this study was to examine the most effective traction direction of the chin cap treating the anterior cross bite on the primary dentition. We therefore created a three-dimensional finite element method model of the mandibulary bone from a dry skull in the primary dentition period. We assumed the effect of the 0 degree, 10 degree and -10 degree of the traction direction from the chin cap to the mandibular condyle loaded on the chin of the mandibulary bone and analized the distribution of the stress and the change in form of the lower primary dentition and mandibulary bone.

The following results were obtained:

1. In the primary dentition, the 0 degree of the traction direction from the chin to the mandibular condyle showed the largest amount of back movement of the primary anterior dentition and lateral movement of the primary posterior teeth.

2. In the mandibulary bone, the 0 degree of the traction direction from the chin to the mandibular condyle showed the largest amount of back movement of the chin, lateral movement of the mandibular angle and under movement of the mandibular angle.

3. In the mandibulary bone, the 0 degree of the traction direction from the chin to the mandibular condyle showed the largest amount of stress of the mandibular cervix.

We believe that this research can be utilized for the guidance, the diagnosis and the treatment of the anterior cross bite on the primary dentition.

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In order to know the present status and problems in pediatric dental care, a questionnaire was answered by 956 pediatric dental specialists who belong to the Japanese Society of Pediatric Dentistry. Summarizing the 455 collected answers, the findings on pediatric dental care of the pediatric dental specialists were as follows.

1. 60% of the pediatric dental specialists estimated that the role of the pediatric dentistry will increase in bringing up the morphology and function of the mouth and teeth of children.

2. Pediatric dental specialists were worrying about the future of pediatric dental care in Japan because the present dental reward system is heading for a structure that is economically difficult for dental offices that focus on pediatric dentistry.

3. Although 70% of the pediatric dental specialists expressed the necessity of a dental office that specializes only in pediatric dentistry, they were thinking it necessary to practice orthodontic and general dentistry at the same time from an economic view point.

4. 90 % of the pediatric dental specialists desire that they can treat patients on both dental treatments covered by the Japanese health insurance and occlusal guidance treatments that are not covered by the insurance, at the same time in order to reduce the frequency and fee of the dental treatment.

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Most studies dealing with the connection between dentition/occlusion and mouth breathing in children were done on hospital-based patients. The purpose of this study was to make a dentitional analysis of primary school children utilizing the raising of children with normal occlusion project conducted in Yamanashi Prefecture in 2002〜2003.

The following results were obtained :

1. The incidence of breathing through the mouth was 29.0% in all children, and that of the lip incompetence was 50.5%.

2. The incidence of abnormal swallowing was 29.9% in all children, and that of the tongue thrust habit was 18.9%. Each of which incidence decreased with age.

3. The mean of lip force increased with age. The mean of lip force of children with incompetent lips was significantly smaller than that of children who constantly closed their lips.

4. Otorhinolaryngological evaluation revealed that the most prevalent conditions present in children were rhinitis, which was found in 18.5% of subjects, and allergic rhinitis, 10.0%.

5. The appearance of maxillary protrusion comparing normal occlusion correlated to the "mouth breathing,""abnormal swallowing,""rhinitis,"of the dental and otorhinolaryngological evaluation ; and "lip biting,""bruxism,""runny nose,""mouth breathing,""swimming school"of the questionnaire survey.

6. The"mouth breathing"of the dental evaluation correlated to the factor of "oral habits",while that of the questionnaire survey correlated to the factor of "nasal airway".

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We surveyed the progression of permanent molar eruption to analyze its difference between the right and left side of the jaw. A total of 476 children were selected among children who visited our clinic, based on specific criteria for this study.

Results

1. The tooth germ of the first molar started moving for eruption at 3-4 years old intramandible, and at 4-5 years intra maxilla. Then the first molar was going to erupt and reached the occlusal plane at 7 years old in mandible, and at 8-9 years old in maxilla although there were individual variations.

2. The cases with differential progression between right and left sides in first molar eruption occupied 13.2%. Unexpectedly, however, the cases with such difference in first molar formation occupied only 7.4%. This suggests that tooth eruption is only partially correlated with its formation and, therefore,additional factors might play a role in tooth eruption, which remains to be elucidated in this study.

3. In most 6-year old children, the root of mandibular first molar completed up to 2/3 of the mature root length, while 1/2 in maxilla. Individual variations were also seen in maxilla.

4. In some cases with the delayed eruption of first molar, the second molars were also delayed to erupt. These first and second molars were not always side by side.

We clinically encounter many cases with a differential progress between the right and left sides in permanent molar eruption. It is not feasible to diagnose these cases as physiological variations or abnormal eruptions. The data presented here will give helpful information to determine whether any treatments are required for these cases.

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In our pediatric dental clinic, we usually apply direct bonding system (DBS) to minor tooth movement.

Accumulation of dental plaque and white spots is seen on the tooth surface around metal brackets in pediatric patients with DBS.

The ratio of S. mutans and S. sobrinus were checked before and after metal bracket attachment by brushing-plaque samples which include plaque, saliva and rinse water just after brushing, for the purpose of clarifying whether metal brackets applied by the DBS causes the dental caries induction. In addition, the frequency of eating snacks containing sucrose was examined before and after metal bracket attachment for 3, 6, 9 and 12 weeks.

The author observed that patients who had without S. mutans before the attachment continue to have the same bacteria condition at 3, 6, 9 and 12 weeks, after metal brackets attachment.

No S. sobrinus was detected before and after treatment in all subjects

In caries free and caries experienced children with detected S. mutans before brackets attachment,the ratio of S. mutans was significantly reduced compared with the initial ratio at 3, 6, 9 and 12 weeks, and 3, 6 and 9 weeks, respectively.

In caries free and caries experienced children with detected S. mutans, the frequency of eating snacks was significantly reduced compared with the initial ratio at 6, 9 and 12 weeks, and 3, 6 and 9 weeks, respectively.

In conclusion, It is suggested that attaching the bracket is not a main risk factor for dental caries in children.

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The present clinical statistic study was performed on 120 pediatric patients who underwent oral surgery at Asunaro Pediatric Dental Clinic in Toyama city over a period of 3 years (2005〜2007).

The results were summarized as follows:

1. The cases of surgery for outpatients had been increasing every year, and the boys to girls ratio was7:5.

2. The removal of impacted supernumerary teeth accounted for 47.5 percent of all surgeries.

3. This study mainly dealt with the removal of supernumerary teeth located around the central incisors, because they accounted for 89.5 percent of all impacted supernumerary teeth. The conclusions were as follows ; (1) The ratio of boys to girls was 5 : 2, (2) 78.4 percent of the cases had one supernumerary tooth, (3) 71.0 percent of the supernumerary teeth were inverted on X-ray films, and (4) the average surgical age was 7.0 years old.

We classified the position of the impacted supernumerary teeth using orthopantomograms. We classified the position of the impacted supernumerary teeth in three categories using orthopantomograms.This classification was useful to estimate the relationship between the vertical position of the impacted supernumerary teeth and the age, and moreover to speculate the difficulty of the surgery.

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Ectodermal dysplasia syndrome is a human inheritance syndrome that affects the hair, teeth, and glands. In four cases (case 3 and 4 are brothers) we managed, we met with the parents and examined the whole body and oral problem.

1.Heat resistance is low and body temperature rises easily because there aren't any sweat glands,therefore patients can't play sports or work when it is hot

2.Parents are dissatisfied with their children's appearances. We present that the recovery of chewing and pronouncing functions, taking the implant treatment into account, reduces their uneasiness.

3.From the questionnaire result we found that it is easy for patients to eat bred or noodles but it is difficult for patients to eat meat. Therefore, it is thought that we need to explain appropriate of meals.

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As the termination of breast-feeding was associated with dental caries susceptibility in our research,a total of 238 children who received dental examinations and obtained information through a ques tionnaire, were subjected to a dental survey. 114 children of the breast-feeding group were categorized into the five groups according to the termination of breast-feeding during the period of 6 months. The rate of maxillary incisors affected by dental caries per infant was calculated and the frequency of sweets and sweet beverages in one day and the Cariostat value were then calculated for each group. Furthermore,98 children with the termination of breast-feeding beyond one year were investigated to assess the frequency of feeding in one day, and the frequency of feeding in one night. Based on the analyses, the following interesting findings were obtained.

1.The longer children were breast-fed, the significantly higher the rate of teeth affected by dental caries was.

2.The longer children were breast-fed, the more significantly the mean number of the frequency of feeding in one day and in one night (beyond one year) was.

3.The longer children were breast-fed, the more significantly the mean number of the frequency of sweets and sweet beverages in one day was.

In conclusion, the children with a longer duration of breast-feeding had a higher rate of teeth affected by dental caries. The children with a longer duration of breast-feeding had a higher frequency of feeding and higher frequency of sweets and sweet beverages.

Moreover, the present results indicate that the higher the frequency of feeding is, the higher the frequency of sweets and sweet beverages is. These findings indicated that a longer duration of breast feeding induced a higher rate of teeth affected by dental caries.

These findings indicated that infant feeding habits, 'Termination of breast-feeding' and 'Frequency of breast-feeding', were strongly associated with dental caries susceptibility per infant.

Moreover, it is indicated that infant feeding habits could be associated with the frequency of sweets and sweet beverages.

It will be important for the support of infant breast-feeding to advise a preventive dental care appropriately.

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A girl, aged 8-years and 10-months old, was brought to our hospital for treatment of the maxillary impacted supernumerary teeth. A radiographic examination revealed that the right maxillary central incisor was impacted, and two supernumerary teeth were located palatal to the left maxillary central incisor and nasally to the impacted right maxillary central incisor.

The right maxillary central incisor was planned to be preserved in this patient. The left supernumerary tooth was first extracted, and through the extraction space, the right supernumerary tooth was exposed and removed. Orthodontic therapy was then performed using a maxilla fixing device and sectional arch to gradually bring the right maxillary central incisor to its proper position. Since the patient's family was planning to move in one year, multibrackets were used during this period to achieve favorable tooth position and occlusion.

In this patient, it was difficult to bring the inverted and impacted central incisor to the proper position orthodontically. Thorough examination and good clinical skills were required to perform the or thodontic therapy, while preserving the dental pulp without damaging the root apex of the central incisor. The impacted supernumerary teeth had to be carefully removed to prevent damage to the central incisor.

The patient and her parents were satisfied with the treatment outcome. In addition to promoting oral development, we were able to gain knowledge and improve our clinical skills.

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Benign cementoblastoma is a comparatively rare odontogenic tumor characterized by hypercementosis. This tumor generally occurs in the lower molar tooth region but rarely in the incisor region.

We experienced a case of benign cementoblastoma that developed around the root apex of the maxillary left central incisor in a 15-year-3-month-old girl. The affected incisor showed a slight discoloration and extrusion of the crown in comparison with the right central incisor. Radiographic examination combined with computed tomography revealed a well-defined, round, radiopaque mass confluent with the root apex of the tooth. After the root canal treatment of the affected incisor was performed because the dental pulp was devitalized, the tumor was removed accompanied with the root resection. Following-up 5 years after the treatment revealed no signs of recurrence.

We attempted a conservative treatment of the affected tooth since the patient was young and the tumor was relatively small. To do the conservative treatment appropriately, the radiographic examination with the computed tomography was important and useful for the diagnosis.

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Traumatic oro-facial injuries are not rare among children. Fractures of one or more teeth, especially young permanent anteriors are common in school children. The partial pulpotomy for traumatic expo sures is a procedure in which the inflamed pulp tissue beneath the exposure is removed to a depth of 2mm to reach the deeper healthy tissue. Pulpal bleeding is controlled, and the site is then covered with calcium hydroxide or MTA. A restoration that seals the tooth from microleakage is placed.

The aim of this case report was to introduce partial pulpotomy treatment and its 5-year- follow-up success in a traumatized permanent incisor of a healthy Japanese boy aged 12 years. Guidelines of the American Academy of Pediatric Dentistry indicate that objectives and procedures for employing available techniques and medicaments, and state that partial pulpotomy technique is a worthy alternative,particularly for immature permanent teeth with exposed vital pulp.

In this case, a healthy permanent left incisor with traumatically complicated crown fracture was treated by partial pulpotomy 2 days after injury, and had been monitored clinically and radiographically for 5 years. At each recall visit, neither spontaneous pain nor periapical radiolucency was found ; the pulp had showed signs of vitality and no periapical lesion had developed. This report suggested that partial pulpotomy was one of the successful pulp treatments for tooth fractures with pulp exposure to conserve as much healthy pulp as possible.

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[in Japanese]

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