Hemophilia is a rare disorder that is characterized by excessive bleeding after injury. This condition requires additional medical attention, including the supplementation of blood coagulation factors, before invasive dental treatment or surgery can be performed. For these reasons, it is important for hemophilic children to make special efforts to prevent oral disease, such as receiving regular dental check-ups. In this study, we investigated the oral health conditions of hemophilic children. The study was carried out during a medical examination in multiple clinical departments at Hiroshima University Hospital in 2015.

The subjects included 31 pediatric patients, of which 30 were male and one was female. The ages of the children ranged from 2 years, 2 months to 17 years, 11 months. The average age was 9 years, 6 months. The results indicated that the prevalence of dental caries was higher in children with hemophilia compared to other children in the same age group. Furthermore, the mean dft/DMFT was higher in children with hemophilia. In terms of periodontal conditions, most of the children with hemophilia displayed pathological findings that included gingival bleeding and calculus deposition. According to the questionnaire, less than half of the hemophilic children were advised to go for regular dental check-ups by a medical doctor and/or dentist.

This survey showed that the oral health conditions of hemophilic children were poor in terms of both dental caries and periodontal conditions. In addition, the study showed that healthcare professionals did not provide these patients with sufficient information to prevent oral disease. A desirable outcome would be to get medical professionals to cooperate in this regard and to educate these patients about the importance of good oral health practices, as well as regular dental check-ups.

We investigated the relationship between sleep nasal obstruction and wearing a device. The indicators of nasal obstruction were nasal airway resistance in the supine position and the five questions about obstructive sleep apnea syndrome (Japanese Sleep Questionnaire for Elementary School Students (JSQ-ES)) of the sleep questionnaire for elementary school children. We compared the two indicators between the group that wore removable orthodontic appliances and the group that did not. As a result, the supine wearing group showed nasal airway resistance values of 0.50 ± 0.13 Pa/cm³/s, and the non-wearing group showed values of 0.70 ± 0.16 Pa/cm³/s, which were significantly larger (p＜0.01). The ratio of resistance in the supine position to that in the sitting position was higher in the non-wearing group than in the wearing group. The total score of the five items of JSQ-ES was 10.5 ± 3.2 points in the wearing group and 12.2 ± 4.0 points in the non-wearing group, which were significantly higher (p＜0.05). A significant positive correlation was found between the supine nasal resistance and the total score of the five JSQ-ES items. We found that nasal obstruction during sleep made it difficult to wear the device. The sum of the five JSQ-ES items in the sleep questionnaire, in which parents of patients subjectively evaluated nasal congestion, reflects supine stuffy nose, which can objectively evaluate nasal congestion. For efficient and safe treatment, we recommend wearing a removable orthodontic appliance based on the diagnosis of nasal resistance.

With the announcement of an action plan to promote countermeasures against antimicrobial drug resistance (AMR) in Japan, our hospital has been working on AMR countermeasures since 2016. Accordingly, we investigated changes over time in the use of oral antimicrobials in pediatric dentistry. Daily Outpatients Dose (density of use of antimicrobials per 1,000 outpatients per day ; DOD) was used to standardize the data. In addition, a comparison with pediatrics was also performed, with Days of Therapy (antimicrobial use period ; DOT) also used as an index.

Before the AMR measures, second- and third-generation cephalosporins accounted for 95% or more of the total ; however, after the measures, the number of antimicrobial drug prescriptions started to decrease. After 2019, the penicillin system accounted for 95% or more. The DOD value for each fiscal year also showed a declining trend, with the lowest value being in 2021.

In the comparison between pediatrics and pediatric dentistry using two kinds of indicators, DOD and DOT, the two indicators indicated similar trends in the prescriptions from pediatric dentistry ; however, it was found that the proportions tended to differ in pediatrics. This was thought to be due to the fact that in pediatric dentistry, the number of prescription days, etc. was determined uniformly.

This survey confirmed the effectiveness of education on AMR countermeasures for healthcare professionals. In order to promote the appropriate use of further antimicrobial drugs, it is necessary to continue to provide education on AMR countermeasures on a regular basis.

Germinated teeth have an incidence rate of 0.05–0.35%, which makes the condition a rare morphological abnormality. Germinated teeth are characterized by the fusion of normal teeth with excess dental germs. When geminated teeth cause abnormal tooth eruption, malalignment, dysfunction, or other problems, comprehensive testing and diagnosis are necessary, followed by an effective treatment plan involving the fusion of normal teeth and excess teeth, and sharing of pulp.

We report a case of spontaneous eruption of an impacted geminated tooth on the right lateral incisor of the maxilla due to separation and removal of the excess tooth. An 8-year, 10-month-old patient had visited a local doctor after experiencing delayed eruption of the maxillary lateral incisor and was referred to our department for further treatment. CT imaging showed the fusion of tooth-like hard tissue in the mesial part of the crown of the maxillary lateral incisor. Since no defect in the adjacent normal tooth was observed and its crown was larger than that of the normal tooth, it was diagnosed as a geminated tooth. We also observed that the pulp cavity was not shared commonly; hence, we decided to promote spontaneous eruption by separating and removing the fused part. After the impacted geminated tooth was separated and removed under general anesthesia, spontaneous eruption of the impacted germinated tooth was observed two months later.

The fused part of the geminated tooth had low dentin calcification, and since the child was susceptible to dental caries and had poor oral prophylaxis, we continued to provide guidance and follow-up. When the child was 10 years old, tooth eruption was observed in the same area as the opposite side, and the periodontal examination showed a relatively good condition. This suggested that natural eruption can be expected by removing a part of the crown that impairs eruption.

In childhood, supernumerary teeth are often observed in the upper anterior teeth region; those observed in the lower premolar region are relatively rare. Supernumerary teeth in the premolar region develop more slowly than those in the anterior teeth region and are difficult to examine or diagnose. This report presents a case in which a supernumerary tooth was observed in the lower right premolar region.

The patient was found to have a supernumerary tooth-like structure in the premolar region by dental radiography performed for caries treatment at a local dental clinic and was referred to our department.

The patient was 4 years and 8 months at the first examination, the Hellman's dental developmental stage was IIA, and caries that reached the pulp cavity was confirmed in the deciduous molar region.

Panoramic radiography showed a supernumerary tooth-like structure above the crown of the lower right premolar, but the crown was in the formation stage, and details of the premolar and supernumerary tooth were unclear.

We first treated caries in the molar region and decided to periodically follow up, waiting for the development of the premolar, and to take necessary measures during the period of successional replacement.

At the age of 8 years and 8 months, the patient's dental developmental reached stage IIIB. As the roots of the first and second deciduous molars were shown to be resorbed by panoramic radiography, and as details of the supernumerary tooth and adjacent teeth could be evaluated in CBCT images, confirming that the supernumerary tooth was causing eruption disturbance of the premolar, the supernumerary tooth was extracted.

The course after tooth extraction was uneventful, and eruption of the premolar was confirmed 2 months after the procedure.

Hypophosphatasia (HPP) is a congenital bone disorder caused by mutations in the gene encoding tissue nonspecific alkaline phosphatase (TNSALP). It is typically associated with premature loss of deciduous teeth; thus, abnormal findings in a dental examination often lead to the diagnosis of HPP. Routine management of patients is critical as the loss of deciduous teeth can have a negative impact on nutritional intake and daily activities. We report the case of a patient with a suspected diagnosis of HPP.

The patient was 5 years and 3 months old at the time of the initial examination. His mother had been diagnosed with, and treated for, HPP. A clinical examination performed at a pediatric clinic showed that the patient had a low level of alkaline phosphatase (ALP); however, genetic testing had not been performed.

At the initial examination, the patient was in stage IIA of Hellman's stage of dental development with significant movement of the right mandibular deciduous central incisor. Dental X-ray performed at the initial examination revealed significant alveolar bone resorption while the root of the right mandibular deciduous central incisor was intact. Thus, we proceeded with plaque control.

At 1 month after the initial examination, the patient lost the right mandibular deciduous central incisor.Due to significant movement of the teeth adjacent to the tooth lost at 5 years and 4 months of age, we placed a pediatric denture in the position as a space maintainer. Since we observed plaque buildup in the maxillary and mandibular anterior teeth, we advised the mother of the patient to help him finish tooth brushing.

With continued management, we observed that the right mandibular central incisor started to grow by the time the patient had reached the age of 5 years and 10 months.

Paramolars are excess teeth that appear on the buccal side of the molars; however, there have been few reports on paramolars. We experienced a case in which a paramolar was found on the buccal side of the maxillary molar. We report here on the clinical course.

The patient was a girl who was 12 years old at the first visit and had an excess tooth on the buccal side near the maxillary molar. From orthopantomography, it was difficult to distinguish between a paramolar cusp (tubercle) of a molar and a paramolar. Therefore, we performed a cone beam CT examination and determined that it was a paramolar.

We planned a paramolar extraction because paramolars may prevent the eruption of and caries in the maxillary molar. In addition, we histologically examined the extracted paramolar, and found that the paramolar was highly likely to have formed at the same time as the adjacent first molar.

In this case, we showed that cone beam CT examination is useful for diagnosing paramolars. Based on a histological analysis of the paramolar, we also suggest that a paramolar may form together with the adjacent first molar.

An 11-year 7-month-old boy came to the pediatric dentistry clinic of the Tokyo Medical and Dental University after a traumatic injury to the jaw 20 days ago. Traumatized teeth were accompanied by increased mobility, percussion pain, and periodontal pocket depth (PPD) of 5 mm. Radiographic examination showed that the left lower lateral incisor had a cervical fracture (root fracture and crown-root fracture). The initial treatment plan was repositioning and splinting of the coronal fragment. After repositioning the incisor, fixation with stainless steel square wire bonded with self-curing resin was performed immediately after cleaning the injured area. One month after the injury, the inflammatory symptoms of the periodontal tissue had improved. After two years of regular follow-up examinations and management, radiographic examination showed radiopacity in the pulp and part of the fractured line. The left lower lateral incisor responded normally to the vitality test. Clinical examination 17 years later revealed that the cervical fractured tooth had been preserved by repositioning, fixation, and thorough oral hygiene management. In addition, continued application of fixation while changing the anchorage unit so as not to inhibit jaw growth and tooth replacement to avoid new trauma enabled long-term tooth preservation.