The epithelial-mesenchymal interaction plays an important role in craniofacial development.It is spatiotemporally regulated by growth and transcription factors and adhesion molecules.Fibroblast Growth Factor (FGF) signaling plays a curial role in not only early gastrulation, but also organogenesis and development related to the epithelial-mesenchymal interaction.We developed epithelial tissue inactivation in fgfr1 or fgfr2 mice. Abnormal tooth calcification and attrition were observed epithelial tissue inactivation in the fgfr1 mouse, and the same symptoms were noticed in the patient with Kallmann syndrome.Epithelial tissue inactivation in the fgfr2 mouse resulted in anomalies of the ears, digits, tooth initiation, and palate development. These are the same symptoms observed in a patient with lacrimoauriculo-dento-digital (LADD) syndrome. A cleft palate and delay in tooth development were observed inactivation in FRS2α mouse.These results revealed that the epithelial and mesenchymal FGF signal plays a curial role in organogenesis and development of the craniofacial region. Genetically modified animals were useful for investigating the cause and determining the therapy of hereditary disorders.

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Recently, several studies have demonstrated that periodontal ligament (PDL) cells differentiate into cementoblastic cells and adipogenic cells in vitro. Therefore, the PDL probably contains pluripotent progenitor cells or putative stem cells. Until now, bone-marrow-derived MSCs (BMMSCs) are good candidates for the treatment of mesenchymal tissue as a source of cells for cell-based therapeutic strategies. Although BMMSCs are very usuful for clinical applications, bone marrow aspiration for MSCs extraction is an invasive and painful procedure for the donor. In addition, the number, proliferation and differentiation potential of BMMSCs decline with increasing age. However, isolating MSCs derived from PDL tissue of deciduous tooth can be non-invasive and economical procedure when permanent tooth replace deciduous tooth.Therefore, it has been thought that PDL cell line from deciduous teeth could be useful tool for the investigation of regenerative medicine. Nevertheless, clonal PDL cell lines have not been established from deciduous teeth.Here, we used human telomerase reverse transcriptase (hTERT) induction to establish the first immortalized PDL cell lines derived from deciduous teeth. We successfully obtained 3 single-cell clones, and named them single cell derived from human deciduous PDL (SH) 9, 10 and 11. All the SH cells showed hTERT expression and stable proliferation after ＞80 population doublings and expressed the marker genes of PDL cells, including scleraxis, periostin, cementum-derived protein 23,and tenomodulin. Although all the clones expressed osteoblastic markers, only the clones from the SH9 cell line differentiated into mature osteoblastic cells which could form calcified nodules in vitro. Recent study have showed that stromal cell-derived factor (SDF)-1 α play a crucial role in stem cell homing and recruitment to injured sites. However, no information is available about SDF-1 α in periodontal tissues. The second aim of this study was to evaluate whether fibroblast growth factor (FGF)-2 and transforming growth factor (TGF)-β1 could affect SDF-1 α expression by immortalized PDL cells derived from deciduous tooth (SH 9 cells) in vitro. FGF-2 inhibited SDF-1 α expression at about 10% of control by 48 h, TGF-β1 induced it at about 6 fold of control between 6 h and 12 h after treatment. These results suggested that SDF-1 α produced by PDL might play an important role in adult stem cell and progenitor cell release, recruitment and homing to injury sites.This is the review of the immortalization of PDL cells derived from deciduous teeth and the regulation of SDF-1 α expression in PDL cells with FGF-2 and TGF-β1. These cells could be useful in studies investigating the cellular mechanisms and regenerative processes of human PDL cells.

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Stomatognathic function in children must not be considered to be the function of small adults. Functional development corresponds with growth during childhood. Adults require maintenace of acquired and known functions. If one of these functions becomes dysfunctional due to disease or trauma, the function can be recovered by rehabilitation. The concept of “habilitation”, namely development of function, is important during childhood, because children need to acquire new functions. It is important to recognize the stage of development at each age by the limitations and inadequacy of aquired functions. Because our research group has pursued various approaches to scientific exploration of stomatognathic function in children, the present review gives an overview of masticatory function in children.Children can perform typical masticatory movements until four years of age, but they don't have mature and developed masticatory function. Pediatric dentists need to recognize the developmental stage of the patient, and find the difference between the present goal of healthy function and the present state of dysfunction. If the dysfunction is a problem, “habilitation” must be performed to achieve the present goal and lead to healthy function in children.

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Streptococcus pyogenes (group A streptococcus) is a pathogen that invades non-phagocytic host cells, and causes a variety of acute infections such as pharyngitis. Our group previously reported that intracellular S. pyogenes is effectively degraded by the host-cell autophagic machinery, and that a cholesterol-dependent cytolysin, streptolysin O (SLO), is associated with bacterial escape from endosomes in epithelial cells. However, the details of both the intracellular behavior of S. pyogenes and the process leading to its autophagic degradation remain unknown. In this study, we found that host small G protein, Rab5, was associated with the pathway of autophagosome formation and the fate of intracellular S. pyogenes. Rab5 was involved in bacterial invasion and endosome fusion. In addition,this study showed that the bacterial cytolysin SLO supported the escape of S. pyogenes into the cytoplasm from endosomes, and surprisingly, a SLO-deficient mutant of S. pyogenes was viable longer than the wild-type strain although it failed to escape the endosomes. This intracellular behavior of S.pyogenes is unique and distinct from that of other types of bacterial invaders. Our results provide a new picture of S. pyogenes infection and host-cell responses in epithelial cells.

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In this article, the historical background of a clinical treatment guideline based on scientific evidence and the build process of the guideline are explained. This article is summarized as follows.1.Eight guidelines associated with dentistry have already been released in Medical information network distribution service (Minds), as of October 2011.2.Ninety-three reviews associated with dentistry have already been released in Cochrane Review, as of October 2011.3.It is important for drawing up clinical treatment guidelines to search systematic literatures. However, it is difficult to find the literatures with high-leveled scientific evidence. As a result, it is also difficult to give high-leveled recommendation to the guideline.4.If a clinical question “What is the effective treatment for the primary tooth with extensive caries when caries removal results in a carious or mechanical pulp exposure with no pulpitis or with reversible pulpitis” is raised, “Guideline on pulp therapy for primary and young permanent teeth” is obtained in the American Academy of Pediatric Dentistry guidelines. Furthermore, the review “Complete or ultraconservative removal of decayed tissue in unfilled teeth” is obtained in Cochrane Review.

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The purpose of this study was to examine the effectiveness of medical support for children with autistic spectrum disorder (ASD) concerning their eating problems in rehabilitation and at home using a survey of eating conditions and assessment of eating and swallowing functions.We studied chief complaints, assessment of eating and swallowing functions, contents of instruction, processes and other factors in 25 children with ASD who visited the eating and swallowing clinic in the Regional Care and Guidance Center.Among the chief complaints, many children had unbalanced diets, swallow foods whole or keep foods in the mouth. Age-related differences were observed. Immaturities in oral function and in the use of goods for eating emerged as eating problems in the younger ASD children, and characteristics such as obsessiveness resulted in unbalanced diets in the older ASD children. The chief complaints in some children did not correspond to their problems in eating and swallowing, possibly caused by incorrect understanding by the parents about eating and swallowing in their children. The way of eating affected oral function. We suggest that medical support should be based on an assessment of eating and swallowing function to deal with eating problems in children with ASD.Because children who received continuous instruction tended to be at a lower development level and have stronger characteristics of autism, we think it is important to stimulate the entire development.

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Human chromogranin A (CgA) in saliva has been used as a stress marker in recent years, however,there have been some negative reports about it. In a pilot study of 88 boys and 90 girls we examined whether CgA was related to Frankl's Behavior Rating Scale and whether it can be applied in today's dental practice through the fisher sealant. The following conclusions were obtained.1.The value of CgA, [after 10 minutes of treatment] was 17.560±12.544 pmol/mg protein, [immediately before treatment] was 16.075±13.019 pmol/mg protein and [10 minutes after treatment] was 11.764±10.239 pmol/mg protein. Moreover, a significant difference was observed between [immediately before treatment] and [10 minutes after treatment], and between [after 10 minutes of treatment] and [10 minutes after treatment], and no significant difference between the sexes was observed.2.A significant negative correlation was observed between the age and the value of CgA at [after 10 minutes of treatment] and [immediately before treatment].3.No relation was observed between the value of CgA and the measurement time.4.Frankl's Behavior Rating Scale was observed in order of Class 3, Class 4, and Class 2.5.A significant correlation was not observed between Frankl's Behavior Rating Scale and the value of CgA in all ages.Quantiative changes in CgA tended to reflect psychological stress, however, it is highly variable and it is almost impossible to arrange conditions for measuring it. It appears that a single clinical application of CgA in saliva is time dependent.

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I report a clinical case of eruption guidance of a partially impacted ankylosed lower left permanent first molar.At the age of 9 years and 6 months the patient had received fenestration because of an unerupted lower left permanent first molar. At the age of 10 years and 1 month, tooth germ of the lower left permanent third molar had been extracted and surgical luxation had been performed on the lower left permanent first molar. Records indicated that the lower left permanent first molar was not ankylosed at that time. However, there was no tendency to erupt.At the age of 11 yaers and 3 months I applied traction. Because there was no tendency to erupt I judged the lower left permanent first molar to be ankylosed, probably due to the surgical luxation at 10 years and 1 month. I applied traction after surgical luxation, but the lower left permanent first molar recured ankylosed. The first time, surgical luxation and traction were spaced 18 days apart. The second time, surgical luxation and traction were spaced 7 days apart. The eruption process was successfully completed under careful observation.We should treat delayed eruption of permanent first molars as soon as possible, choosing the proper treatment plan.

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Heamophilia A is an X-chromosome-linked congenital bleeding disorder, caused by a deficiency of the coagulant factor. Typical manifestations of this disorder are soft tissue, muscle, and joint hemorrhages. Heamophilia occurs in approximately 1 in 10,000 males for factor-VIII deficiency- heamophilia A and 1 in 50,000 for factor-IX deficiency-heamophilia B. Individuals with less than 1 IU/dl active factor are classified as having severe heamophilia, those with 2−5 IU/dl active factor have moderate heamophilia, and those with mild heamophilia have between 6−40 IU/dl of normal levels of active clotting factor.Patients with heamophilia often report a history of prolonged and unusual bleeding associated with minor trauma or oral surgical procedures.Exfoliation and extraction of the primary teeth can lead to unusual bleeding and it is often difficult to stop bleeding in children with bleeding disorders.A 10-year-old boy reported to our hospital with a chief complaint of pain in the upper left first primary molar. The X-ray revealed advanced root resorption. We asked the patient for his medical and dental history. Although the patient had several prior episodes of internal bleeding from stumbling since infancy, periodic medical examinations had ruled out a bleeding disorder. The management of hemostasis presented difficulties after tooth extraction and we suspected case of mild bleeding disorder. The diagnosis of heamophilia A was confirmed by a blood test. The patient was allowed to return home after hemostasis had been confirmed within 20 minutes.However, bleeding was observed several times after the extraction, and hemostasis was achieved using suture and CO2 laser under infiltration anesthesia. We recommended a blood examination at a children's hospital where, the activated partial thromboplastin time (APTT) was 27.8% and 33.8% on two different laboratory tests. The patient was diagnosed as having heamophilia A.

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