Background : Human beta-defensins (hBDs) belong to a group of antimicrobial peptides, expressed mainly in epithelial cells, that contribute to both innate and adaptive immunity. Stress affects multiple components of the immune systems. The human stress response is orchestrated by the hypothalamicpituitary-adrenal axis acting via corticosteroids. Recently, dexamethasone (Dex), a potent synthetic corticosteroid, was shown to alter expression of hBDs in bronchial, tracheal and corneal epithelia, and carcinoma cell lines. Expressions of hBD-2 and hBD-3 are upregulated by stimulation during bacterial infection. It is, however, still unknown how Dex alters hBDs expression in human keratinocytes during bacterial infection. Bacterial structures are recognized by innate immunity receptors such as Tolllike receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) on the surface of oral mucosa. Therefore, the present study investigated the effect of Dex on hBDs expression by stimulation with TLR2 and TLR4 in human normal keratinocytes.Methods : Human normal keratinocytes (NHEK) were grown in hydrocortisone-free keratinocyte basal medium. The cells were treated in the presence or absence of 10, 1 and 0.1 μM Dex for 24 hrs,followed by 24 hrs with or without TLRs agonists. The cells were treated with MAPK/ERK inhibitor(PD 98059) for intracellular pathways in a series of experiments. Expression of hBD-1, hBD-2, hBD3, TLR2 and TLR4 in NHEK cells were observed by RT-PCR, quantitative RT-PCR and ELISA. The expression level of hBD-1, hBD-2 and hBD-3 mRNA were standardized against GAPDH mRNA. The relative expression of each mRNA was calculated as the 2^{−ΔΔ Ct} method. The data was analyzed using the student-t test. Differences between experimental groups were considered statistically significant at the p＜0.05 levels.Results : Both TLR2 and TLR4 agonists induced upregulation of hBD-1 and hBD-2 in NHEK. The hBD-3 peptide level in the cells incubated with Dex was significantly lower than in the non-treated control cells (p＜0.05). The MAPK/ERK inhibitor significantly decreased the expression levels of hBDs mRNA in the cells incubated with Dex (p＜0.05). In the cells incubated with both Dex and TLR4 agonist, the expression level of hBD-1 and hBD-2 mRNA was significantly lower than in cells incubated with TLR4 agonist alone (p＜0.05). The expression levels of hBD-3 mRNA was significantly lower than that of controls in the cells incubated with both Dex and TLR2 agonist (p＜0.05) Conclusion : The results indicate that corticosteroids may inhibit upregulated expression of hBDs in human normal keratinocytes during bacterial infection via the MAPK/ERK pathway.

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The factors involved in melanin pigmentation in children's gingiva was examined. The subjects were 50 Japanese children aged 3−11 years, and their mothers, visiting the Department of Pediatric Dentistry, Hiroshima University Hospital. They participated in this study after receiving sufficient informed consent. Melanin pigmentation was evaluated for darkness of the gingiva and the area of the coloration. Gingival darkness was categorized into four stages. The area of the coloration was categorized into five stages, according to a previous manuscript. Other factors examined for involvement in melanin pigmentation in the present study were : passive exposure to tobacco smoke, exposure of the maxillary gingiva during laughing (so-called gummy smile), suntan, color of hair, concentration of cotinine in the saliva, an unbalanced diet, oral breathing, age and sex.Statistical correlations were found between gingival darkness and suntan, color of hair, period of passive exposure to tobacco smoke, age and oral breathing. The area of gingival coloration correlated with suntan, color of hair and period of passive exposure to tobacco smoke.

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As the birthrate continues to fall and extreme aging of the population progresses, the governmentand social systems tend to focus on aged individuals. However, health conditions during childhoodgreatly affect the presence or absence of dental problems in adulthood and the older years. Oralhealth and treatment in childhood are therefore extremely important. In this study, questionnaire surveyswere conducted regarding 1) the results of the 2010 revisions in payment for dental service, and2) the periodontal tissue examination of the mixed-dentition. Questionnaires were given to 130 executivemembers of the Japanese Society of Pediatric Dentistry, and analysis was performed on 58 memberswho responded (44.6%). The following results were obtained :1. Results of the revisions in the payment for dental service were considered “very good” by 3.5% ofrespondents, “slightly good” by 39.6%, “quite bad” by 5.2%, “slightly bad” by 17.2%, and “no different”by 34.5%, respectively.2. Comparing the total payment between this year and last year, there was a 1.7% increase in April, a0.6% decrease in May, and a 0.7% decrease in June.3. Causes for the increases in the total payment were given as “an increase of the payment in firstand subsequent visits” by 92.9% of participants, “re-implementation of the additional payment forthose under 6 years old” by 88.9%, and “expansion of infant medical and dental expense aid in municipalities”by 48.0%.4. Causes for decreases of the payment were given as “a decrease in the number of visits by children”by 55.6% of participants, and “a decrease in dental caries” by 52%. Furthermore, 39.1% recognizedthe introduction of ”the periodontal tissue examination of the mixed dentition” as causing a decreasein the payment while 60.9% did not.5. Regarding the ratios of executing the various periodontal tissue examinations, the ratio of executingthe periodontal tissue examination of the mixed-dentition was 30.7% in April, 35.7% in May, and35.2% in June. The ratio of executing the basic periodontal examinations was 31.4% in April, 29.1%in May, and 29.8% in June. The ratio of not making an estimate was 37.9% in April, 35.2% in May,and 35.0% in June, which was more than one third.6. Regarding the amount of time required for examinations, “the periodontal tissue examination of themixed dentition” took roughly 7.3 minutes, “the basic periodontal examinations” took roughly 7.2minutes, and “the complete periodontal examinations” took roughly 13.3 minutes.7. Widespread implementation of the periodontal tissue examination of the deciduous- and mixeddentitionis necessary for prevention of periodontal diseases in adulthood. Examination methods touse during the deciduous- and mixed-dentition period and examination forms were devised.

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A girl, 8 years and 8 months old, with congenitally missing mandibular second premolars was treated with this altered method of serial extraction. Extraction was chosen because her teeth were large. The mandibular second deciduous molars were extracted according to following steps. First, the distal crown portion of each mandibular second deciduous molar was sliced with high-speed bar. Second, the distal crown and root portion of each mandibular second deciduous molar was hemisectioned and extracted, allowing the mandibular first molars to drift mesialy. Third, the maxillary first premolars and the mesial crown and root portion of the mandibular second deciduous molars were extracted when the mandibular first molars moved mesialy and were close to them. Finally, the mandibular first molars moved further mesially closing the space spontaneously.The extraction spaces were closed spontaneously and the dentition was in alignment until 13 years and 6 months of age. Space closure was finished after the mandibular second molars had alreadyerupted, suggesting that the mandibular third molars are especially related to the space closure.Although long-term observation was necessary in this case, this altered method of serial extraction has the advantage of using no appliances and facilitating orthodontic treatment.

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Irritation fibroma is an overgrowth of submucosal tissue caused by prolonged local irritation from teeth or dental prostheses. It is extremely rare during the first decade of life and usually occurs in adult women.We encountered a one-year-11-month-old boy who had an overgrowth of palatal gingival tissue,subsequently diagnosed as irritation fibroma.A good prognosis was obtained after the removal of the fibroma with Er : YAG laser. We used Erwin AdvErL, (Morita MGF) as the laser apparatus, and the irradiation condition was 100 mJ, 10 pps or 20 pps performed with either a cone- or brush- shaped irradiation tip. The boy was cooperative throughout the surgical procedure and did not complain of any discomfort after the operation. The definitive diagnosis of irritation fibroma was provided after pathological examination, and gingival stimulation from thumb sucking was thought to be the cause of the progression of the lesion.These results suggest that the Er : YAG laser is useful for minor surgery in pediatric dentistry.

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Congenital insensitivity to pain with anhidrosis (CIPA) is a type IV hereditary sensory and autonomic neuropathy associated with an autosomal recessive genetic disease with mental retardation.CIPA individuals lack pain sensation and perspiration function due to the absence of unmyelinated Cand thin myelinated Aδ fibers. However, since thick myelinated Aβ fibers are present, tactile sensation is considered to be functioning. Patients with this disease show bite wounds to the tongue, lips,and fingers due to self-mutilation, and conduct self tooth extraction that occasionally causes mandibular osteomyelitis ; therefore, it is a disease for which dental treatment and care are important.In this study, an 11-year and 5-month-old girl, diagnosed with CIPA, exhibited mandibular osteomyelitis due to self tooth extraction. Six teeth were lost in 2 months, and sequestrectomy was performed in the area.Before surgery, dental pulp vitality was assessed in our department to determine the removal range of mandibular sequesters and indicate which teeth required extraction. Since all of the teeth measured were non-responsive to a conventional electric pulp test (EPT) this dental pulp vitality diagnostic test was considered useless, and the presence of pulp pulse waves was examined using transmitted-light plethysmography (TLP), in which the presence of pulpal blood flow could be objectively measured.As a result, the presence of pulp pulse waves in the mandibular right second premolar, located in the border region of sequesters, was confirmed. The tooth was diagnosed as vital, and was preserved without performing tooth extraction. TLP appears to be very useful for the diagnosis of teeth in patients with congenital insensitivity to pain with anhidrosis. At 10 months after surgery, a favorable clinical course has been shown based on TLP and X-ray examinations of the preserved tooth and mandibular bone.

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Pediatric dentists examine various traumata of deciduous teeth in clinical practice. Root fractures are relatively uncommon among the dental traumata. A treatment for a root-fractured deciduous tooth without dislocation and mobility is not necessary. A treatment for the root-fractured deciduous tooth with dislocation and mobility is tooth extraction by IADT guidelines. Because self-reparation by hard tissue formation, which is observed in a permanent tooth, is not observed in the deciduous tooth fixed for a long time.We reduced and fixed a deciduous maxillary central incisor with the root fracture of a 1-year and5-month-old infant to preserve the deciduous central incisor. The process of healing by hard tissue formation has been good for 1-year and 6-months. The present paper describes the healing process.

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Although impaction of primary teeth is much rarer than that of permanent teeth, detecting impaction early is extremely important to prevent delayed eruption, malposition, and hypoplasia of permanent successor teeth. We encountered a case of a completely impacted mandibular right primary second molar with eruption by fenestration and traction.A 2-year-8-month-old boy who had been periodically examined since age 1 was suspected of having an impacted mandibular right primary second molar. He was diagnosed using panoramic radiography at 4 years and 3 months of age. The mandibular right primary second molar was impacted with distal inclination and had a pericoronal radiolucent area with radiopaque object. The mandibular right permanent first molar had a cystic lesion around the crown.At 5 years 2 months of age, elimination of a hamartomatous lesion and fenestration were done under general anesthesia. After the observation period of six months from the operation, traction was started. The mandibular right primary second molar erupted after one year. The mandibular right permanent first molar erupted at 8 years 7 months of age. Soon after the mandibular right primary second molar was shed, the mandibular right permanent second premolar erupted at 10 years 11 months of age.In this case, early discovery and initiation of treatment at the correct time facilitated eruption of the mandibular right primary second molar. Long-term observation revealed prompt growth of the mandibular right permanent first molar and the mandibular right permanent second premolar. Results show that continued periodic examination is important for growth of a healthy permanent dentition.

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