Oral myofunctional therapy (MFT) is a specialized training technique taught to patients for selftreatment of a variety of oral muscle functional disorders and habit patterns that disrupt normal oral and dental development. Although various training methods have been proposed, there are few reports on the effects of training in individual subjects. The purpose of this study was to clarify the effects of various MFT methods in 20 children (15 boys, 5 girls : average age 7 years 7 months) who underwent training at our hospital. The results revealed that the percentage of children with poor lip seal improved from 55% to 33%,while tongue thrust during swallowing and articulating improved from 100% to 50% and 95% to 60% respectively. We also found that “Water Slurp Swallow” training significantly contributed to improved tongue thrust during swallowing. However, even though the subjects were able to master the training methods, they failed to obtain correct oral functions, thus new training methods as well as the timing for starting training must be considered. Oral function is regarded as important throughout life, with childhood a crucial stage for establishing a healthy foundation. Our results also showed that 20% of the child subjects had oral functional difficulties without morphological problems, indicating that both morphological and functional problems should be evaluated. MFT is an effective method for support of oral function and development.

A clinic for treating dysphagia disorders in children was established as part of the Department of Pediatric Dentistry of Kagoshima University Hospital in July 2010. We evaluated the state of dysphagia in all patients at the time of their first visit to the clinic during a 5-year period. There were 194 patients (112 males, 82 females; average age 3 years 9 months, range 0 to 17 years 11 months) who visited our clinic for dysphagia disorder. Approximately half were referred by medical facilities near our clinic, while only 1% were introduced from remote hospitals in rural areas. Nearly all of the patients were affected by underlying disease, and 20% had low body weight at birth or preterm delivery, or showed immature basic motor functions. It is important to provide patient support in the early stage by use of an interdisciplinary approach for improvement of dysphagia. A pediatric dentist is also needed to manage improvement of orofacial form and function for development of eating function.

We conducted a survey to examine the effects of mouth breathing in children on sleep and daytime activities. There were 165 subjects aged 3 to 12 years (73 boys, 92 girls ;mean age 8.3±2.3 years) without a significant medical history who were examined at dental clinics in Kagoshima Prefecture,Japan, in July and August 2017. We found that 27.3% snored and 2.4% stopped breathing during sleep, while mouth breathing was observed in 16.4%. Children who exhibited mouth breathing also showed chest retraction, open mouth during sleep, snoring, difficulty with waking, history of common colds, a runny nose, dysphagia, daytime somnolence, attention deficit, and hyperactivity. We consider that our findings indicate that mouth breathing has major effects on sleep and daily activities of chil­dren. Pediatric dentists seek to contribute to the healthy growth and development of children by care for their oral cavity. In addition to addressing morphological and functional problems, such as caries, hard­-tissue disease, maxillofacial, dentition and occlusion disorders, and mastication and swallowing disorders, the present results show the importance of providing sufficient attention to potential respira­tory disorders.

The prevalence of dental caries is low in younger children, while rapid progression occurs in adolescence. The purpose of this study was to clarify the association of prevalence of dental caries in children and daily lifestyle habits. A total of 100 children (57 boys, 43 girls, average age 4 years 6 months) who visited our department were enrolled and divided into the caries and non-caries group. Each parent or guardian was asked regarding the daily lifestyle of the child, including nutrition and oral health. We found that "maternal employment", "bedtime", and "frequent snacks" were correlated with dental caries prevalence. There was no significant differences in regard to "living with grandparents","presence of brothers and/or sisters", "wake-up time", and "knowledge of dental health". Furthermore, we found that all children with caries ate excessively during meals, excluding snacks. Dental health promotion contributes to specifically target dental caries, while establishment of healthy lifestyle habits in children, particularly healthy habits for eating, is important.

We conducted a survey to select questions that teachers could easily and reliably answer as part of a basic research project to create a questionnaire based on characteristic behaviors exhibited by abused children at primary school for screening of those who may need welfare assistance. Questionnaires comprised of 35 items were sent to 64 primary school teachers, with the same questionnaire sent again 2 weeks later. Responses to both were compared to examine ease of assessing the contents of the questions, reproducibility of the responses, and written expressions.

1) Items that teachers found difficult to assess at school were "Does not wash hands after using the toilet," "Does not bring homemade lunch to events," "Does not meet guardian's eyes ;appears apprehensive," "Has experienced a change in familial relations," "Uses sexual speech and behavior that is not age appropriate," "Does not see a doctor despite being sick," and "Is excessively wary."

2) Items that showed responses with low reliability were "Is too thin," "Does not bring homemade lunch to events," "Is often absent from the classroom," and "Does not meet guardian's eyes; appears apprehensive."

3) Items indicated to use inappropriate expressions were "Sometimes tells lies," "Is bullied by friends," and "Does not fit in with group in some ways."

Next, use of a questionnaire that does not include the above items should be done with actual children to examine its effectiveness as an indicator for screening children who require welfare assistance.

The aim of this study was to investigate the recent tendency of first-time patients examined at the Department of Pediatric Dentistry of a university hospital in central Tokyo to be affected by mucosal disease. We conducted a survey of 315 children (181 boys, 134 girls; infancy to 15 years of age, mean age 4.7 years, largest age group 6 years) who first visited our hospital between April 2010 and March 2016 for an oral mucosal condition. They comprised 6.8% of all pediatric patients who visited for the first time during this 6-year span. Of those 315 patients with oral mucosal complaints, 243 were from the 23 wards of Tokyo, 26 lived in other areas of Tokyo, and 46 lived outside of Tokyo. Moreover, 221 were referred from another hospital or dental clinic, whereas 104 patients came without a referral letter.

The investigated patients were diagnosed with various forms of oral mucosal lesions, including ankyloglossia (n=91), abnormal superior labial frenulum (n=58), and mucosal cysts (n=53). Following the initial examination, a medical follow-up examination was recommended for 263 and mucosa treatment for 37, while referral to another professional within the hospital, such as an oral surgeon or speech-language-hearing specialist, was recommended for 15. Most of the 6-year-olds were diagnosed with ankyloglossia. A majority of patients who underwent a frenotomy procedure, or received either speech therapy or evaluation by a speech-language-hearing specialist were 5 years old. Of the 7-year-old patients, most showed an abnormal superior frenulum and underwent a frenotomy. Patients with a mucosal cyst ranged in age from 1 to 8 years, most of whom underwent enucleation at 5 to 7 years old.

Young children with oral mucosal lesions are increasingly coming to our university hospital, thus accurate diagnosis is necessary to determine whether medical or surgical treatment is needed. For management of patients with oral mucosal lesions, cooperation of university hospital dental staff with those of nearby hospitals and dental clinics, as well as other specialists within the university hospital, including oral surgeons and speech-language-hearing therapists, is vital.

To examine strategies for prevention of injury in primary dentition, we determined the number of children with dental trauma, and place and cause of injury according to age, and analyzed details of similar cases using the medical records of 0- to 5-year-old children who visited Osaka Dental University Hospital over the recent decade. The following findings were obtained.

1)A total of 3238 medical records of first-visit patients who were 0-5 years old were reviewed. Of those patients, 312 (9.6%) showed primary tooth dental trauma. Dental trauma was seen most often in those aged 1 year, followed by patients 2 years old.

2)Of children aged 2-4 years, 65-75% were injured at home, while 3- to 4-year-old children were injured at various places, such as kindergarten or nursery school, parks, and roads. Indoor facilities were often the place of injury for 5-year-old children.

3)Regarding occurrence at home, about 40% of the 1- and 2-year-old groups in particular were injured in the living room, kitchen, or bedroom, with most cases in association with and impact with furniture, especially tables. Stairs accounted for 7.4% of the injuries at home, with the majority injured there in the 1-year-old group. At kindergarten and nursery school, more injuries occurred at indoor rather than outdoor locations. The number of children injured at parks increased with age. Playground equipment, especially slides (about 40%), were frequently associated with injury.

4)The most common cause of injury in all age groups was falling. Many of the children in the 0- and 5-year-old groups suffered from a fall, while collisions were common in children aged 1 to 4 years old.

5)There were 9 similar cases in which a specific primary injury frequently occurred.

Our results suggest that education is necessary regarding prevention of dental trauma for guardians, especially those with younger children with a high risk of dental trauma due to the early stage of development.

Using anonymous data of the Comprehensive Survey of Living Conditions, a relative evaluation of oral and other subjective symptoms and disease during childhood was carried out, and their relationship to living conditions was examined. The subjects were 2,129 respondents of the 2010 Comprehensive Survey of Living Conditions aged 0-14 years.

A comparative analysis of items was carried out using a contingency table. For items with a high response rate, a hierarchical cluster analysis was performed to find similarity between responses. The results were as follows :

1.The number of persons with subjective symptoms was 502 (23.6%), and the number of persons attending hospital was 413 (19.4%).

2.With both the name of the symptoms and the name of the disease, items relating to the respiratory system and skin ranked high.

3.Dental symptoms ranked low in the ranking of symptoms, but among the names of disease of greatest concern, a dental disease was in second place.

4.In the hierarchical cluster analysis results, name of skin symptoms and name of disease were positioned near everyday awareness and total home income on the dendrogram, suggesting a relation ship.

These results indicate a need to understand the characteristics of the responses and the relative evaluation of the names of symptoms and disease during childhood in order to examine future dental health measures on the basis of the trends observed.

The authors evaluated the level of cooperation by 255 healthy children (147 boys, 108 girls ;2­9 years old) during their initial examination as well as in 3 subsequent examinations performed at the outpatient clinic of the Pediatric Dentistry Department, Tsurumi University Dental Hospital. Changes in level of cooperation with the progress of treatment were evaluated using Frankl's Behavior Rating Scale, with the following results obtained.

1.Overall, Class 3 cooperation had the highest and Class 1 the lowest frequency at each recording point of all 4 visits for each age group. Moreover, the frequency of Class 1 and 2 tended to de­ crease with increasing age.

2.When the level of cooperation was classified into 2 groups, namely, "uncooperative" (Class 1 and 2)and "cooperative" (Class 3 and 4), the time point of assessment was an independent factor in 3­ -year-­old children. In addition, the frequency of "cooperative" and "uncooperative" became reversed at the age of 3 years.

3.When changes in the level of cooperation in each age group were evaluated, the most frequently observed patterns were "continually cooperative" in all subjects, "continually uncooperative" in 2­ and 3­-year-­old children, and "continually cooperative" in 4­ to 9­-year-­old children. In addition, the frequency of being "continually cooperative" was significantly low in 2­ and 3­-year-­old children and significantly high in 6­ to 9­-year-­old children, that of "becoming cooperative" was signifi­cantly low in 2­-year-­old children and significantly high in 3­-year-­old children, that of "inconsis­tent" was significantly high in 4­ and 5­-year-­old children, and that of "less cooperative" was sig­nificantly high in 4­-year-­old children.

Our results indicated that the level of cooperation was low in 2­-year-­old children at every assess­ment point from the first to fourth visits. In 3­-year-­old children, the level of cooperation was low at the first visit but increased as treatments continued. In children 4 years old and older, the level of co­ operation was high from the first visit. Finally, the level of cooperation was nearly satisfactory in all by the time the children reached school age.

Dens evaginatus is an anomaly frequently observed in mandibular premolars. In affected patients with a fracture that occurs during the process of tooth eruption, treatments that induce root lengthening and apical root closure are crucial. During performance of such procedures, formation of a dentin bridge and apical root closure are mainly confirmed by dental radiography or with use of a file, though the latter technique provides less conclusive clinical findings.

We perform pulp treatment for immature mandibular secondary premolars with acute suppurative pulpitis secondary to fractured dens evaginatus. Dental pulp and apical root closure are examined by microscopy and dental cone beam computed tomography (CBCT). A patient came to our hospital with pain in the left mandibular premolars due to fractured dens evaginatus, which had been diagnosed by the referring physician. An intraoral examination revealed fractured dens evaginatus and a diagnosis of acute suppurative pulpitis was made. We performed tooth extraction under local anesthesia, though the apical pulp remained. We then conducted apexogenesis, which encouraged apical root closure and root lengthening as a result of dentin bridge-like hard tissue formation on the dental pulp section, confirmed by dental radiography observation. For the final restoration, we conducted close visual examinations using microscopy and CBCT after obtaining consent from the legal guardians. Finally, we performed composite resin treatment after confirming that the dental pulp section was sealed and the apical root was closed into a form that most resembled its normal shape, with consideration of the thickened dentin bridge-like hard tissue.

Our results suggest that visual examinations via microscopy and CBCT are important for root canal structural analysis following treatment of immature teeth among the wide range of available therapies.

Teeth with a supernumerary root, such as a double, additional, extra, or accessory root, or multiple roots, are a deviation from the general form. A supernumerary root can occur in nearly all types of permanent teeth, while it is extremely rare in deciduous teeth. In Japan, there are only a few clinical reports of such an occurrence in maxillary and mandible primary canines, or maxillary second and mandibular primary molars, while clinical reports of a maxillary primary central incisor with a supernumerary root are available. Here, we report a case of a maxillary primary central incisor with an additional root that caused disturbance of permanent tooth eruption.