Publications by authors named "Ichiro Takahashi"

174 Publications

Characteristics of craniofacial morphology and factors affecting them in patients with isolated cleft palate.

PeerJ 2021 20;9:e11297. Epub 2021 Apr 20.

Section of Orthodontics and Dentofacial Orthopedics, Faculty of Dental Science, Kyushu University, Fukuoka, Fukuoka, Japan.

Background: Myriad maxillo-mandibular occlusal relationships are observed in patients with isolated cleft palate (ICP), unlike in patients with other cleft types, such as cleft lip and palate.

Objectives: This study aimed to categorise the characteristics of craniofacial morphology in patients with ICP, and investigate the clinical factors affecting these categorised morphological characteristics.

Methods: Thirty-six girls with ICP (age (mean ± SD): 5.36 ± 0.36 years) underwent cephalometric measurement. Their craniofacial morphology was categorised using cluster analysis. Profilograms were created and superimposed onto the standard Japanese profilograms to visualise the morphological characteristics of each group (cluster). The mean values and variations in the linear and angular measurements of each group were compared with the Japanese standards and statistically analysed using Dunnett's test after the analysis of variance. Fisher's exact test was used to analyse the differences between the cleft types (cleft in the hard and/or soft palate) and skills of the operating surgeons in the groups.

Results: Cluster analysis of craniofacial morphologies in patients with ICP resulted in the formation of three categories: the first cluster exhibited a relatively harmonious anteroposterior relationship between the maxilla and the mandible (22.2%); the second cluster exhibited crossbite owing to a significantly smaller maxilla (33.3%); and the third cluster exhibited a smaller mandible with posterior rotation showing skeletal class II malocclusion (44.4%). Differences in cleft types and surgeons were not associated with the distribution of patients in each cluster.

Conclusions: Patients with ICP exhibited characteristic morphological patterns, such as bimaxillary retrusion or severe mandibular retrusion, besides the anterior crossbite frequently found in patients with cleft lip and palate . Understanding the typical morphological characteristics could enable better diagnostic categorisation of patients with ICP, which may eventually improve orthodontic treatment planning.
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http://dx.doi.org/10.7717/peerj.11297DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8063870PMC
April 2021

Mathematical modeling of palatal suture pattern formation: morphological differences between sagittal and palatal sutures.

Sci Rep 2021 Apr 26;11(1):8995. Epub 2021 Apr 26.

Department of Anatomy and Cell Biology, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.

The median palatal suture serves as a growth center for the maxilla; inadequate growth at this site causes malocclusion and dental crowding. However, the pattern formation mechanism of palatal sutures is poorly understood compared with that of calvarial sutures such as the sagittal suture. In the present study, therefore, we compared the morphological characteristics of sagittal and palatal sutures in human bone specimens. We found that palatal suture width was narrower than sagittal suture width, and the interdigitation amplitude of the palatal suture was lower than that of the sagittal suture. These tendencies were also observed in the neonatal stage. However, such differences were not observed in other animals such as chimpanzees and mice. We also used a mathematical model to reproduce the differences between palatal and sagittal sutures. After an extensive parameter search, we found two conditions that could generate the difference in interdigitation amplitude and suture width: bone differentiation threshold [Formula: see text] and growth speed c. We discuss possible biological interpretations of the observed pattern difference and its cause.
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http://dx.doi.org/10.1038/s41598-021-88255-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8076228PMC
April 2021

Mouse Embryonic Tooth Germ Dissection and Culture Protocol.

Bio Protoc 2020 Feb 5;10(3):e3515. Epub 2020 Feb 5.

Division of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, Sendai, Japan.

A tooth germ organ culture allows visualization of its development in different stages, thus enabling investigation of the molecular mechanisms of regulatory factors. Tooth germs can be rapidly dissected from E13 mouse embryos and placed on cell culture inserts for observation of subsequent tooth germ development in a three-dimensional situation in real time. This method is also suitable for other organs that develop by epithelial-mesenchymal interactions, including salivary gland, hair, lung, and kidney. In addition, siRNAs or growth factors can be easily added to tooth germ cultures to investigate the detailed molecular function of specific genes. The present protocol provides an efficient and practical method for isolation and culture of embryonic tooth germs.
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http://dx.doi.org/10.21769/BioProtoc.3515DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7842286PMC
February 2020

Erratum for Compressive Force-Produced CCN2 Induces Osteocyte Apoptosis through ERK1/2 Pathway.

J Bone Miner Res 2020 Nov 16;35(11):2303-2304. Epub 2020 Sep 16.

Division of Orthodontics and Dentofacial Orthopedics, Tohoku University Graduate School of Dentistry, Sendai, Japan.

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http://dx.doi.org/10.1002/jbmr.4169DOI Listing
November 2020

Systemic Exposure to Lipopolysaccharide from Porphyromonas gingivalis Induces Bone Loss-Correlated Alzheimer's Disease-Like Pathologies in Middle-Aged Mice.

J Alzheimers Dis 2020 ;78(1):61-74

Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.

Background: Alzheimer's disease (AD) and bone loss are clinically exacerbated. However, the mechanism of exacerbation remains understood.

Objective: We tested our hypothesis that periodontitis is involved in the exacerbation, contributing to AD pathologies.

Methods: The bone, memory, and inflammation in bone and brain were examined in 12-month-old mice after systemic exposure to lipopolysaccharide from Porphyromonas gingivalis (P gLPS) for 3 consecutive weeks.

Results: Compared with control mice, bone loss in tibia (26% decrease) and memory decline (47% decrease) were induced in mice with a positive correlation after exposure to P gLPS (r = 0.7378, p = 0.0011). The IL-6 and IL-17 expression in tibia was negatively correlated with the bone volume/total tissue volume (r = -0.6619, p = 0.0052; r = -0.7129, p = 0.0019), while that in the cortex was negatively correlated with the memory test latency (r = -0.7198, p = 0.0017; p = 0.0351, r = -0.5291). Furthermore, the IL-17 expression in microglia was positively correlated with Aβ42 accumulation in neurons (r = 0.8635, p < 0.0001). In cultured MG6 microglia, the P gLPS-increased IL-6 expression was inhibited by a PI3K-specific inhibitor (68% decrease), and that of IL-17 was inhibited by IL-6 antibody (41% decrease). In cultured N2a neurons, conditioned medium from P gLPS-stimulated microglia (MCM) but not P gLPS increased the productions of AβPP, CatB, and Aβ42, which were significantly inhibited by pre-treatment with IL-17 antibody (67%, 51%, and 41% decrease).

Conclusion: These findings demonstrated that chronic systemic exposure to P gLPS simultaneously induces inflammation-dependent bone loss and AD-like pathologies by elevating IL-6 and IL-17 from middle age, suggesting that periodontal bacteria induce exacerbation of bone loss and memory decline, resulting in AD progression.
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http://dx.doi.org/10.3233/JAD-200689DOI Listing
January 2020

Extracellular vesicles from deciduous pulp stem cells recover bone loss by regulating telomerase activity in an osteoporosis mouse model.

Stem Cell Res Ther 2020 07 17;11(1):296. Epub 2020 Jul 17.

Department of Molecular Cell Biology and Oral Anatomy, Division of Oral Biological Sciences, Graduate School of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.

Background: Systemic transplantation of stem cells from human exfoliated deciduous teeth (SHED) recovers bone loss in animal models of osteoporosis; however, the mechanisms underlying this remain unclear. Here, we hypothesized that trophic factors within SHED-releasing extracellular vesicles (SHED-EVs) rescue osteoporotic phenotype.

Methods: EVs were isolated from culture supernatant of SHED. SHED-EVs were treated with or without ribonuclease and systemically administrated into ovariectomized mice, followed by the function of recipient bone marrow mesenchymal stem cells (BMMSCs) including telomerase activity, osteoblast differentiation, and sepmaphorine-3A (SEMA3A) secretion. Subsequently, human BMMSCs were stimulated by SHED-EVs with or without ribonuclease treatment, and then human BMMSCs were examined regarding the function of telomerase activity, osteoblast differentiation, and SEMA3A secretion. Furthermore, SHED-EV-treated human BMMSCs were subcutaneously transplanted into the dorsal skin of immunocompromised mice with hydroxyapatite tricalcium phosphate (HA/TCP) careers and analyzed the de novo bone-forming ability.

Results: We revealed that systemic SHED-EV-infusion recovered bone volume in ovariectomized mice and improved the function of recipient BMMSCs by rescuing the mRNA levels of Tert and telomerase activity, osteoblast differentiation, and SEMA3A secretion. Ribonuclease treatment depleted RNAs, including microRNAs, within SHED-EVs, and these RNA-depleted SHED-EVs attenuated SHED-EV-rescued function of recipient BMMSCs in the ovariectomized mice. These findings were supported by in vitro assays using human BMMSCs incubated with SHED-EVs.

Conclusion: Collectively, our findings suggest that SHED-secreted RNAs, such as microRNAs, play a crucial role in treating postmenopausal osteoporosis by targeting the telomerase activity of recipient BMMSCs.
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http://dx.doi.org/10.1186/s13287-020-01818-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7367365PMC
July 2020

The development, validation, and psychometric properties of the Japanese version of the Child Oral Health Impact Profile-Short Form 19 (COHIP-SF 19) for school-age children.

Health Qual Life Outcomes 2020 Jul 11;18(1):224. Epub 2020 Jul 11.

Section of Orthodontics and Dentofacial Orthopedics, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka, 812-8582, Japan.

Background: This study was performed to develop and validate a Japanese version of Child Oral Health Impact Profile-Short Form (COHIP-SF) 19 and to assess its psychometric properties in Japanese school-age children.

Methods: The original English COHIP-SF 19 was translated into Japanese (COHIP-SF 19 JP) using a standard forward and backward translation procedure. The psychometric properties of the COHIP-SF 19 JP were assessed in 379 public school students between 7 and 18 years of age in Fukuoka, Japan. Internal consistency (Cronbach's alpha) and test-retest reliability (intraclass correlation coefficient, ICC) were the metrics used for evaluation of this questionnaire. The discriminant validly was examined using the Wilcoxon rank sum test to identify significant differences in COHIP-SF 19 JP scores according to the results of dental examinations. The convergent validity was examined using the Spearman correlations to determine the relationships between COHIP-SF 19 JP scores and the self-perceived oral health ratings. Confirmatory factor analyses (CFA) were performed to verify the factor structure of the questionnaire.

Results: The COHIP-SF 19 JP revealed good internal consistency (Cronbach's alpha, 0.77) and test-retest reliability (ICC, 0.81). Discriminant validity indicated that children with dental caries or malocclusion had significantly lower COHIP-SF 19 JP scores (P <  0.05); convergent validity indicated that the self-perceived oral health rating was significantly correlated with the COHIP-SF 19 JP total score and subscores (rs = 0.352-0.567, P <  0.0001), indicating that the questionnaire had a sufficient construct validity. CFA suggested that the modified four-factor model had better model fit indices than the original three-factor model.

Conclusion: The collected data showed that the COHIP-SF 19 JP possesses sufficient psychometric properties for use in Japanese school-age children.
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http://dx.doi.org/10.1186/s12955-020-01469-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7353691PMC
July 2020

microRNA-875-5p plays critical role for mesenchymal condensation in epithelial-mesenchymal interaction during tooth development.

Sci Rep 2020 03 18;10(1):4918. Epub 2020 Mar 18.

Division of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, Sendai, Japan.

Epithelial-mesenchymal interaction has critical roles for organ development including teeth, during which epithelial thickening and mesenchymal condensation are initiated by precise regulation of the signaling pathway. In teeth, neural crest-derived mesenchymal cells expressed PDGF receptors migrate and become condensed toward invaginated epithelium. To identify the molecular mechanism of this interaction, we explored the specific transcriptional start sites (TSSs) of tooth organs using cap analysis of gene expression (CAGE). We identified a tooth specific TSS detected in the chromosome 15qD1 region, which codes microRNA-875 (mir875). MiR875-5p is specifically expressed in dental mesenchyme during the early stage of tooth development. Furthermore, PRRX1/2 binds to the mir875 promoter region and enhances the expression of mir875. To assess the role of miR875-5p in dental mesenchyme, we transfected mimic miR875-5p into mouse dental pulp (mDP) cells, which showed that cell migration toward dental epithelial cells was significantly induced by miR875-5p via the PDGF signaling pathway. Those results also demonstrated that miR875-5p induces cell migration by inhibiting PTEN and STAT1, which are regulated by miR875-5p as part of post-transcriptional regulation. Together, our findings indicate that tooth specific miR875-5p has important roles in cell condensation of mesenchymal cells around invaginated dental epithelium and induction of epithelial-mesenchymal interaction.
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http://dx.doi.org/10.1038/s41598-020-61693-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7080778PMC
March 2020

Expression of protocadherin-20 in mouse taste buds.

Sci Rep 2020 02 6;10(1):2051. Epub 2020 Feb 6.

Section of Oral Neuroscience, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.

Taste information is detected by taste cells and then transmitted to the brain through the taste nerve fibers. According to our previous data, there may be specific coding of taste quality between taste cells and nerve fibers. However, the molecular mechanisms underlying this coding specificity remain unclear. The purpose of this study was to identify candidate molecules that may regulate the specific coding. GeneChip analysis of mRNA isolated from the mice taste papillae and taste ganglia revealed that 14 members of the cadherin superfamily, which are important regulators of synapse formation and plasticity, were expressed in both tissues. Among them, protocadherin-20 (Pcdh20) was highly expressed in a subset of taste bud cells, and co-expressed with taste receptor type 1 member 3 (T1R3, a marker of sweet- or umami-sensitive taste cells) but not gustducin or carbonic anhydrase-4 (markers of bitter/sweet- and sour-sensitive taste cells, respectively) in circumvallate papillae. Furthermore, Pcdh20 expression in taste cells occurred later than T1R3 expression during the morphogenesis of taste papillae. Thus, Pcdh20 may be involved in taste quality-specific connections between differentiated taste cells and their partner neurons, thereby acting as a molecular tag for the coding of sweet and/or umami taste.
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http://dx.doi.org/10.1038/s41598-020-58991-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7005180PMC
February 2020

Persistent colonization of non-lymphoid tissue-resident macrophages by Stenotrophomonas maltophilia.

Int Immunol 2020 02;32(2):133-141

International Research and Development Center for Mucosal Vaccines, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.

Accumulating evidence has revealed that lymphoid tissue-resident commensal bacteria (e.g. Alcaligenes spp.) survive within dendritic cells. We extended our previous study by investigating microbes that persistently colonize colonic macrophages. 16S rRNA-based metagenome analysis using DNA purified from murine colonic macrophages revealed the presence of Stenotrophomonas maltophilia. The in situ intracellular colonization by S. maltophilia was recapitulated in vitro by using bone marrow-derived macrophages (BMDMs). Co-culture of BMDMs with clinically isolated S. maltophilia led to increased mitochondrial respiration and robust IL-10 production. We further identified a 25-kDa protein encoded by the gene assigned as smlt2713 (recently renamed as SMLT_RS12935) and secreted by S. maltophilia as the factor responsible for enhanced IL-10 production by BMDMs. IL-10 production is critical for maintenance of the symbiotic condition, because intracellular colonization by S. maltophilia was impaired in IL-10-deficient BMDMs, and smlt2713-deficient S. maltophilia failed to persistently colonize IL-10-competent BMDMs. These findings indicate a novel commensal network between colonic macrophages and S. maltophilia that is mediated by IL-10 and smlt2713.
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http://dx.doi.org/10.1093/intimm/dxz071DOI Listing
February 2020

Identification of Initial Colonizing Bacteria in Dental Plaques from Young Adults Using Full-Length 16S rRNA Gene Sequencing.

mSystems 2019 Sep 3;4(5). Epub 2019 Sep 3.

Section of Preventive and Public Health Dentistry, Division of Oral Health, Growth and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan

Development of dental plaque begins with the adhesion of salivary bacteria to the acquired pellicle covering the tooth surface. In this study, we collected dental plaque formed on hydroxyapatite disks for 6 h from 74 young adults and identified initial colonizing taxa based on full-length 16S rRNA gene sequences. A long-read, single-molecule sequencer, PacBio Sequel, provided 100,109 high-quality full-length 16S rRNA gene sequence reads from the early plaque microbiota, which were assigned to 90 oral bacterial taxa. The microbiota obtained from every individual mostly comprised the 21 predominant taxa with the maximum relative abundance of over 10% (95.8 ± 6.2%, mean ± SD), which included species as well as nonstreptococcal species. A hierarchical cluster analysis of their relative abundance distribution suggested three major patterns of microbiota compositions: a / sp. HMT-423-dominant profile, a //-dominant profile, and a complex profile with high diversity. No notable variations in the community structures were associated with the dental caries status, although the total bacterial amounts were larger in the subjects with a high number of caries-experienced teeth (≥8) than in those with no or a low number of caries-experienced teeth. Our results revealed the bacterial taxa primarily involved in early plaque formation on hydroxyapatite disks in young adults. Selective attachment of salivary bacteria to the tooth surface is an initial and repetitive phase in dental plaque development. We employed full-length 16S rRNA gene sequence analysis with a high taxonomic resolution using a third-generation sequencer, PacBio Sequel, to determine the bacterial composition during early plaque formation in 74 young adults accurately and in detail. The results revealed 21 bacterial taxa primarily involved in early plaque formation on hydroxyapatite disks in young adults, which include several streptococcal species as well as nonstreptococcal species, such as // and Given that no notable variations in the microbiota composition were associated with the dental caries status, the maturation process, rather than the specific bacterial species that are the initial colonizers, is likely to play an important role in the development of dysbiotic microbiota associated with dental caries.
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http://dx.doi.org/10.1128/mSystems.00360-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6722423PMC
September 2019

Transition of Bacterial Diversity and Composition in Tongue Microbiota during the First Two Years of Life.

mSphere 2019 05 29;4(3). Epub 2019 May 29.

Section of Preventive and Public Health Dentistry, Division of Oral Health, Growth and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan

Newborns are constantly exposed to various microbes from birth; hence, diverse commensal bacteria colonize the oral cavity. However, how or when these bacteria construct a complex and stable ecosystem remains unclear. This prospective cohort study examined the temporal changes in bacterial diversity and composition in tongue microbiota during infancy. We longitudinally collected a total of 464 tongue swab samples from 8 infants (age of <6 months at baseline) for approximately 2 years. We also collected samples from 32 children (aged 0 to 2 years) and 73 adults (aged 20 to 29 years) cross-sectionally as control groups. Bacterial diversities and compositions were determined by 16S rRNA gene sequencing. The tongue bacterial diversity in infancy, measured as the number of observed operational taxonomic units (OTUs), rapidly increased and nearly reached the same level as that in adults by around 80 weeks. The overall tongue bacterial composition in the transitional phase, 80 to 120 weeks, was more similar to that of adults than to that of the early exponential phase (EEP), 10 to 29 weeks, according to analysis of similarities. Dominant OTUs in the EEP corresponding to and exponentially decreased immediately after EEP, around 30 to 49 weeks, whereas several OTUs corresponding to , , and reciprocally increased during the same period. These results suggest that a drastic compositional shift of tongue microbiota occurs before the age of 1 year, and then bacterial diversity and overall bacterial composition reach levels comparable to those in adults by the age of 2 years. Evaluating the development of oral microbiota during infancy is important for understanding the subsequent colonization of bacterial species and the process of formation of mature microbiota in the oral cavity. We examined tongue microbiota longitudinally collected from 8 infants and found that drastic compositional shifts in tongue microbiota occur before the age of 1 year, and then bacterial diversity and overall bacterial composition reach levels comparable to those in adults by the age of 2 years. These results may be helpful for preventing the development of various diseases associated with oral microbiota throughout life.
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http://dx.doi.org/10.1128/mSphere.00187-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6541735PMC
May 2019

Effect of loaded orthodontic miniscrew implant on compressive stresses in adjacent periodontal ligament.

Angle Orthod 2019 03 19;89(2):235-241. Epub 2018 Sep 19.

Objectives: To describe the relationship between the proximity of miniscrew implants (MSIs) to the periodontal ligament (PDL) and stress in the PDL under different load magnitudes and different bone properties.

Materials And Methods: Sixteen subject-specific finite element models of the region of the maxillary first molar and second premolar were developed using computed tomography images of four patients. For each patient, an MSI surface model derived from micro-computed tomography was placed at four different distances from the premolar PDL. Finite element analysis was conducted with mesial load on the MSI, increasing from 1 N to 4 N. Peak absolute compression stress (CS) was calculated at each 1 N step. Stepwise multiple regression modeling was conducted to explain compressive stress by proximity, load magnitude, and bone properties.

Results: The multiple regression model explained 83.47% of the variation of CS and included all three factors: proximity, load magnitude, and bone properties. The model expected significant interaction between the bone properties and load magnitude, implying that strong bone properties could be associated with significant increases in CS at small increases in load.

Conclusions: To ensure the safety of adjacent roots, MSIs should be placed at least 1 mm from the roots. Assessment of alveolar bone properties is recommended when the use of MSI is intended, as some patients may present with strong bone properties and thereby a high risk of MSI-induced root resorption.
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http://dx.doi.org/10.2319/122017-873.1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8120879PMC
March 2019

Intracytoplasmic eosinophilic inclusion bodies with embryonic folliculosebaceous-apocrine unit differentiation in syringocystadenoma papilliferum.

J Cutan Pathol 2018 Dec 24;45(12):923-926. Epub 2018 Sep 24.

Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan.

We describe a case of syringocystadenoma papilliferum (SCAP) with a unique histopathology. A 50-year-old Japanese woman presented with a pedunculated tumor in the pubic region. Histopathological examination showed that the tumor was composed of basaloid cell proliferation interconnecting from the epidermis to the dermis. Ductal structures in the tumor were lined by club-shaped columnar cells with apical snouts. Interestingly, numerous vacuolated cells with hyaline globule-like cytoplasmic inclusions were present among the columnar cells, the content of which was identified as sialomucin. Electron microscopy revealed that the vacuolated cytosol of luminal cells represented intracytoplasmic lumens with a structure similar to embryonic apocrine ducts. We assumed that this case represents a rare variant of SCAP that had differentiated toward the embryonic folliculosebaceous-apocrine unit.
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http://dx.doi.org/10.1111/cup.13344DOI Listing
December 2018

The transcription factor NKX2-3 mediates p21 expression and ectodysplasin-A signaling in the enamel knot for cusp formation in tooth development.

J Biol Chem 2018 09 8;293(38):14572-14584. Epub 2018 Aug 8.

the Division of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, Sendai 980-8575, and

Tooth morphogenesis is initiated by reciprocal interactions between the ectoderm and neural crest-derived mesenchyme. During tooth development, tooth cusps are regulated by precise control of proliferation of cell clusters, termed enamel knots, that are present among dental epithelial cells. The interaction of ectodysplasin-A (EDA) with its receptor, EDAR, plays a critical role in cusp formation by these enamel knots, and mutations of these genes is a cause of ectodermal dysplasia. It has also been reported that deficiency in , encoding a member of the NK2 homeobox family of transcription factors, leads to cusp absence in affected teeth. However, the molecular role of NKX2-3 in tooth morphogenesis is not clearly understood. Using gene microarray analysis in mouse embryos, we found that is highly expressed during tooth development and increased during the tooth morphogenesis, especially during cusp formation. We also demonstrate that NKX2-3 is a target molecule of EDA and critical for expression of the cell cycle regulator p21 in the enamel knot. Moreover, NKX2-3 activated the bone morphogenetic protein (BMP) signaling pathway by up-regulating expression levels of and in dental epithelium and decreased the expression of the dental epithelial stem cell marker SRY box 2 (SOX2). Together, our results indicate that EDA/NKX2-3 signaling is essential for enamel knot formation during tooth morphogenesis in mice.
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http://dx.doi.org/10.1074/jbc.RA118.003373DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6153296PMC
September 2018

Enhancement of Self-Aggregation Properties of Linear Elastin-Derived Short Peptides by Simple Cyclization: Strong Self-Aggregation Properties of Cyclo[FPGVG] , Consisting Only of Natural Amino Acids.

Biomacromolecules 2018 08 9;19(8):3201-3211. Epub 2018 Jul 9.

Faculty of Arts and Science , Kyushu University , Fukuoka 819-0395 , Japan.

Elastin-like peptides (ELPs) consist of distinctive repetitive sequences, such as (VPGVG) , exhibit temperature-dependent reversible self-assembly (coacervation), and have been considered to be useful for the development of thermoresponsive materials. Further fundamental studies evaluating coacervative properties of novel nonlinear ELPs could present design concepts for new thermoresponsive materials. In this study, we prepared novel ELPs, cyclic (FPGVG) (cyclo[FPGVG] , n = 1-5), and analyzed their self-assembly properties and structural characteristics. Cyclo[FPGVG] ( n = 3-5) demonstrated stronger coacervation capacity than the corresponding linear peptides. The coacervate of cyclo[FPGVG] was able to retain water-soluble dye molecules at 40 °C, which implied that cyclo[FPGVG] could be employed as a base material of DDS (drug delivery system) matrices and other biomaterials. The results of molecular dynamics simulations and circular dichroism measurements suggested that a certain chain length was required for cyclo[FPGVG] to demonstrate alterations in molecular structure that were critical to the exhibition of coacervation.
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http://dx.doi.org/10.1021/acs.biomac.8b00353DOI Listing
August 2018

The Rare Disease Bank of Japan: establishment, current status and future challenges.

Hum Cell 2018 Jul 2;31(3):183-188. Epub 2018 Apr 2.

Laboratory of Rare Disease Biospecimen, Center for Rare Disease Research, National Institutes of Biomedical Innovation, Health and Nutrition, 7-6-8, Saito-Asagi, Ibaraki, Osaka, 567-0085, Japan.

Research on rare diseases cannot be performed without appropriate samples from patients with such diseases. Due to the limited number of such patients, securing biosamples of sufficient quality for extensive research is a challenge and represents an important barrier to the advancement of research on rare diseases. To tackle this problem, the Rare Disease Bank (RDB) was established in 2009 at the National Institute of Biomedical Innovation (NIBIO; currently, the National Institutes of Biomedical Innovation, Health and Nutrition in Japan). Since then, the RDB has focused on three objectives: (1) emphasizing the importance of collecting biosamples from patients with rare diseases, together with appropriate clinical information, from various medical facilities nationwide; (2) maintaining strict high-quality sample management standards; and (3) sharing biosamples with research scientists across Japan for the advancement of research on rare diseases. As of August 2017, the bank has collected 4147 biosamples from patients with rare diseases, including DNA, serum, plasma, and cell samples from various university hospitals and other medical institutions across the country, and provided various research institutions with 13,686 biosample aliquots from 2850 cases. In addition, the management committee has successfully established a bank system that provides high-quality biosamples together with the results of human leukocyte antigen analysis. It is anticipated that the RDB, through the collection and sharing of biosamples with the medical research community, will enhance the understanding, prevention, and treatment of rare diseases in Japan and the world at large.
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http://dx.doi.org/10.1007/s13577-018-0204-3DOI Listing
July 2018

Three-dimensional titanium miniplates for fixation of subcondylar mandibular fractures: Comparison of five designs using patient-specific finite element analysis.

J Craniomaxillofac Surg 2018 Mar 26;46(3):391-397. Epub 2017 Dec 26.

Department of Orthodontics and Dentofacial Orthopedics, Faculty of Dental Science, Kyushu University, Japan. Electronic address:

Purpose: The purpose of the current study is to compare the performance of five designs of three-dimensional titanium miniplates (lambda, strut, delta, rhombic and trapezoid) for fixation of subcondylar mandibular fracture.

Materials And Methods: Three-dimensional models were constructed for the five miniplates with their screws and integrated into a virtually fractured mandible that was derived from a computed tomographic image of living human. Patient-specific finite element models were analyzed to compare the performances of the miniplates. Miniplates were compared for titanium hardware volume, condylar head displacement, bone strains and miniplates' stresses.

Results: Least condylar head displacement, and thereby best fixation primary stability, was found in the trapezoid miniplate. On the other hand, the greatest displacements were found in lambda and strut miniplates. Bone strains, as an indicator of secondary stability, predicted high strains in bone around the screws affixing the delta miniplate. Therefore, high risk of failure due to screws loosening is expected when using the delta miniplate. Stresses in miniplates were excessive in the strut and lambda miniplates, which implies a high risk of miniplate fracture.

Conclusions: The current findings predicted significant differences in performance among the different designs of three-dimensional miniplates. The trapezoid miniplate seems to have the best performance, as it provided the greatest rigidity with relatively low bone strains.
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http://dx.doi.org/10.1016/j.jcms.2017.12.020DOI Listing
March 2018

Cathepsin S Is Involved in Th17 Differentiation Through the Upregulation of IL-6 by Activating PAR-2 after Systemic Exposure to Lipopolysaccharide from .

Front Pharmacol 2017 17;8:470. Epub 2017 Jul 17.

Section of Orthodontics and Dentofacial Orthopedics, Kyushu UniversityFukuoka, Japan.

Positive links have been found between periodontitis and numerous diseases in humans via persistent inflammation throughout the body. However, the main factors responsible for maintaining this pro-inflammatory condition are poorly understood. The spleen, the largest secondary immune organ, is a central hub regulating the immune response/inflammation due to the dendritic cell (DC) response to CD4 T cell subtype differentiation, and lysosomal proteinase cathepsin S (CatS) is known to be involved in DC functions. In the present study, we found that CatS-induced IL-6 production by splenic DCs subsequently promotes Th17 differentiation, in response to systemic exposure to lipopolysaccharide derived from (PgLPS). The population of CD11c DCs was significantly increased in the splenic marginal zone (MZ) locally of wild-type (DBA/2) mice with splenomegaly but not in that of CatS deficient ( ) mice after systemic exposure to PgLPS for 7 consecutive days (5 mg/kg/day, intraperitoneal). Similarly, the population of Th17CD4 T cells was also significantly increased in the splenic MZ of wild-type mice but not in that of mice after PgLPS exposure. Furthermore, the increase in the Th17 CD4 T cell population paralleled increases in the levels of CatS and IL-6 in CD11c cells in the splenic MZ. In isolated primary splenic CD11c cells, the mRNA expression and the production of IL-6 was dramatically increased in wild-type mice but not in mice after direct stimulation with PgLPS (1 μg/ml), and this PgLPS-induced increase in the IL-6 expression was completely abolished by pre-treatment with Z-Phe-Leu-COCHO (Z-FL), the specific inhibitor of CatS. The PgLPS activated protease-activated receptor (PAR) 2 in the isolated splenic CD11c cells was also significantly inhibited by deficiently. In addition, the PgLPSinduced increase in the IL-6 production by splenic CD11c cells was completely abolished by pre-treatment with FSLLRY-NH, a PAR2 antagonist, as well as Akti, a specific inhibitor of Akt. These findings indicate that CatS plays a critical role in driving splenic DC-dependent Th17 differentiation through the upregulation of IL-6 by activating PAR2 after exposure to components of periodontal bacteria. Therefore, CatS-specific inhibitors may be effective in alleviating periodontitis-related immune/inflammation.
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http://dx.doi.org/10.3389/fphar.2017.00470DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5511830PMC
July 2017

A case of cutaneous polyarteritis nodosa with PR3-ANCA.

Eur J Dermatol 2017 10;27(5):524-525

Department of Dermatology, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo, 060-8638, Japan.

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http://dx.doi.org/10.1684/ejd.2017.3070DOI Listing
October 2017

Mediator 1 contributes to enamel mineralization as a coactivator for Notch1 signaling and stimulates transcription of the alkaline phosphatase gene.

J Biol Chem 2017 08 3;292(33):13531-13540. Epub 2017 Jul 3.

From the Laboratory of Cell and Developmental Biology, NIDCR, National Institutes of Health, Bethesda, Maryland 20892,

Tooth enamel is mineralized through the differentiation of multiple dental epithelia including ameloblasts and the stratum intermedium (SI), and this differentiation is controlled by several signaling pathways. Previously, we demonstrated that the transcriptional coactivator Mediator 1 (MED1) plays a critical role in enamel formation. For instance, conditional ablation of in dental epithelia causes functional changes in incisor-specific dental epithelial stem cells, resulting in mineralization defects in the adult incisors. However, the molecular mechanism by which deficiency causes these abnormalities is not clear. Here, we demonstrated that ablation causes early SI differentiation defects resulting in enamel hypoplasia of the -deficient molars. deletion prevented Notch1-mediated differentiation of the SI cells resulting in decreased alkaline phosphatase (ALPL), which is essential for mineralization. However, it does not affect the ability of ameloblasts to produce enamel matrix proteins. Using the dental epithelial SF2 cell line, we demonstrated that MED1 directly activates transcription of the gene through the stimulation of Notch1 signaling by forming a complex with cleaved Notch1-RBP-Jk on the promoter. These results suggest that MED1 may be essential for enamel matrix mineralization by serving as a coactivator for Notch1 signaling regulating transcription of the gene.
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http://dx.doi.org/10.1074/jbc.M117.780866DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5566513PMC
August 2017

Nephronectin plays critical roles in Sox2 expression and proliferation in dental epithelial stem cells via EGF-like repeat domains.

Sci Rep 2017 03 27;7:45181. Epub 2017 Mar 27.

Division of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan.

Tooth development is initiated by epithelial-mesenchymal interactions via basement membrane (BM) and growth factors. In the present study, we found that nephronectin (Npnt), a component of the BM, is highly expressed in the developing tooth. Npnt localizes in the BM on the buccal side of the tooth germ and shows an expression pattern opposite that of the dental epithelial stem cell marker Sox2. To identify the roles of Npnt during tooth development, we performed knockdown and overexpression experiments using ex vivo organ and dental epithelial cell cultures. Our findings showed that loss of Npnt induced ectopic Sox2-positive cells and reduced tooth germ size. Over expression of Npnt showed increased proliferation, whereas the number of Sox2-positive cells was decreased in dental epithelial cells. Npnt contains 5 EGF-like repeat domains, as well as an RGD sequence and MAM domain. We found that the EGF-like repeats are critical for Sox2 expression and cell proliferation. Furthermore, Npnt activated the EGF receptor (EGFR) via the EGF-like repeat domains and induced the PI3K-Akt signaling pathway. Our results indicate that Npnt plays a critical scaffold role in dental epithelial stem cell differentiation and proliferation, and regulates Sox2 expression during tooth development.
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http://dx.doi.org/10.1038/srep45181DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5366923PMC
March 2017

Translational Repression of a Splice Variant of Cynomolgus Macaque CXCL1L by Its C-Terminal Sequence.

J Interferon Cytokine Res 2017 03 10;37(3):129-138. Epub 2017 Feb 10.

5 The Health and Kampo Institute , Sendai, Japan .

We previously isolated a cDNA clone from cynomolgus macaque encoding a novel CXC chemokine that we termed CXCL1L from its close similarity to CXCL1. However, the cDNA consisted of 3 exons instead of 4 exons that were typically seen in other CXC chemokines. Here, we isolated a cDNA encoding the full-length variant of CXCL1L that we termed CXCL1Lβ. CXCL1Lβ is 50 amino acids longer than the original CXCL1L, which we now term CXCL1Lα. The CXCL1Lβ mRNA is much more abundantly expressed in the cynomolgus macaque tissues than CXCL1Lα mRNA. However, CXCL1Lβ protein was poorly produced by transfected cells compared with that of CXCL1Lα. When the coding region of the fourth exon was fused to the C-terminus of CXCL1 or even to a nonsecretory protein firefly luciferase, the fused proteins were also barely produced, although the mRNAs were abundantly expressed. The polysome profiling analysis suggested that the inhibition was mainly at the translational level. Furthermore, we demonstrated that the C-terminal 5 amino acids of CXCL1Lβ were critical for the translational repression. The present study, thus, reveals a unique translational regulation controlling the production of a splicing variant of CXCL1L. Since the CXCL1L gene is functional only in the Old World monkeys, we also discuss possible reasons for the conservation of the active CXCL1L gene in these monkeys during the primate evolution.
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http://dx.doi.org/10.1089/jir.2016.0085DOI Listing
March 2017

Bullous lichen planus accompanied by elevation of serum anti-BP180 autoantibody: A possible transitional mechanism to lichen planus pemphigoides.

J Dermatol 2017 Jun 20;44(6):e124-e125. Epub 2017 Jan 20.

Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan.

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http://dx.doi.org/10.1111/1346-8138.13732DOI Listing
June 2017

Exploration of bacterial species associated with the salivary microbiome of individuals with a low susceptibility to dental caries.

Clin Oral Investig 2017 Nov 24;21(8):2399-2406. Epub 2016 Dec 24.

Section of Preventive and Public Health Dentistry, Division of Oral Health, Growth and Development, Kyushu University Faculty of Dental Science, Fukuoka, Japan.

Objective: Dental caries is caused by acidogenic plaque microbiota formed on saliva-bathed tooth surfaces, in which multiple organisms act collectively to initiate and expand a cavity. We explored bacterial species associated with the salivary microbiome of individuals with low susceptibility to dental caries.

Materials And Methods: The bacterial composition of saliva from 19 young adults was analyzed using barcoded pyrosequencing of the 16S rRNA gene; we compared 10 caries-experienced (CE) and nine caries-free (CF) individuals. A quantitative PCR assay of saliva from 139 orally healthy adults aged 40-59 years was carried out to confirm the result obtained by pyrosequencing analysis.

Results: The microbiomes of CF individuals showed more diverse communities with a significantly greater proportion of the genus Porphyromonas. Among operational taxonomic units (OTUs) corresponding to the genus Porphyromonas, the OTU corresponding to P. pasteri was the most predominant and its relative abundance in CF individuals was significantly greater than in CE individuals (P < 0.001, Wilcoxon rank sum test). A quantitative PCR assay of saliva confirmed that the amounts of P. pasteri were significantly higher in individuals with lower caries experience (filled teeth <15, n = 67) than in those with higher caries experience (filled teeth ≥15, n = 72) (P < 0.001, Student's t test).

Conclusion: These results revealed an association between a greater abundance of P. pasteri and lower susceptibility to dental caries.

Clinical Relevance: P. pasteri may be a bacterial species that could potentially be used as a marker for maintaining a healthy oral microbiome against dental caries.
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http://dx.doi.org/10.1007/s00784-016-2035-5DOI Listing
November 2017

Simian immunodeficiency virus SIVmac239 infection and simian human immunodeficiency virus SHIV89.6P infection result in progression to AIDS in cynomolgus macaques of Asian origin.

J Gen Virol 2016 Dec 21;97(12):3413-3426. Epub 2016 Oct 21.

Laboratory of Immunoregulation and Vaccine Research, Tsukuba Primate Research Center, National Institutes of Biomedical Innovation, Health and Nutrition, Tsukuba, Ibaraki 305-0843, Japan.

Simian immunodeficiency virus (SIV) infection models in cynomolgus macaques are important for analysis of the pathogenesis of immunodeficiency virus and for studies on the efficacy of new vaccine candidates. However, very little is known about the pathogenesis of SIV or simian human immunodeficiency virus (SHIV) in cynomolgus macaques from different Asian countries. In the present study, we analysed the infectivity and pathogenicity of CCR5-tropic SIVmac and those of dual-tropic SHIV89.6P inoculated into cynomolgus macaques in Indonesian, Malaysian or Philippine origin. The plasma viral loads in macaques infected with either SIVmac239 or SHIV89.6P were maintained at high levels. CD4+ T cell levels in macaques infected with SIVmac239 gradually decreased. All of the macaques infected with SHIV89.6P showed greatly reduced CD4+ T-cell numbers within 6 weeks of infection. Eight of the 11 macaques infected with SIVmac239 were killed due to AIDS symptoms after 2-4.5 years, while four of the five macaques infected with SHIV89.6P were killed due to AIDS symptoms after 1-3.5 years. We also analysed cynomolgus macaques infected intrarectally with repeated low, medium or high doses of SIVmac239, SIVmac251 or SHIV89.6P. Infection was confirmed by quantitative RT-PCR at more than 5000, 300 and 500 TCID50 for SIVmac239, SIVmac251 and SHIV89.6P, respectively. The present study indicates that cynomolgus macaques of Asian origin are highly susceptible to SIVmac and SHIV infection by both intravenous and mucosal routes. These models will be useful for studies on virus pathogenesis, vaccination and therapeutics against human immunodeficiency virus/AIDS.
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http://dx.doi.org/10.1099/jgv.0.000641DOI Listing
December 2016

Kaposi's varicelliform eruption presenting with extensive skin lesions and sepsis.

J Dermatol 2017 Oct 24;44(10):1180-1181. Epub 2016 Nov 24.

Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan.

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http://dx.doi.org/10.1111/1346-8138.13674DOI Listing
October 2017

A Longitudinal Study of the Presence of Dental Anomalies in the Primary and Permanent Dentitions of Cleft Lip and/or Palate Patients.

Cleft Palate Craniofac J 2017 05 31;54(3):309-320. Epub 2016 Mar 31.

Objective: The aim is to survey primary and permanent dental anomalies: hypodontia, microdontia, a supernumerary tooth, and fused teeth in patients with cleft lip and/or palate.

Design: Retrospective longitudinal study Subjects :  The subjects were selected from all 1724 patients with cleft lip and/or palate who were registered at the orthodontic clinic of Kyushu University Hospital, Fukuoka, Japan, from 1970 to 2009. Finally, 994 subjects were evaluated for primary dentition, 1352 for permanent dentition, and 871 for the longitudinal changes from primary to permanent dentition.

Methods: The prevalence of dental anomalies was compared for each tooth type, among various cleft types, between males and females, and between the alveolar cleft area and the noncleft area.

Results: The prevalence of hypodontia was 16.2% for primary dentition and 52.7% for permanent dentition in the subjects with cleft lip and/or palate. Hypodontia increased with the severity of the cleft type. Multiple hypodontia was found more frequently in the subjects with bilateral cleft lip and palate and the subjects with unilateral cleft lip and palate. Microformed lateral incisors were found in 22.7% of permanent lateral incisors but not in primary dentition. Supernumerary teeth were found in 17.7% of the subjects with cleft lip and/or palate for primary maxillary dentition and in 5.7% for permanent maxillary dentition.

Conclusion: The prevalence of hypodontia was greater in permanent dentition than in primary dentition; although, it was not much different between males and females or between the right and left sides. The prevalence of dental anomalies was significantly different among four groups by cleft type: cleft lip, cleft lip and alveolus, cleft lip and palate, and cleft palate.
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http://dx.doi.org/10.1597/15-186DOI Listing
May 2017

Plakophilin-1, a Novel Wnt Signaling Regulator, Is Critical for Tooth Development and Ameloblast Differentiation.

PLoS One 2016 24;11(3):e0152206. Epub 2016 Mar 24.

Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.

Tooth morphogenesis is initiated by reciprocal interactions between the ectoderm and neural crest-derived mesenchyme, and the Wnt signaling pathway is involved in this process. We found that Plakophilin (PKP)1, which is associated with diseases such as ectodermal dysplasia/skin fragility syndrome, was highly expressed in teeth and skin, and was upregulated during tooth development. We hypothesized that PKP1 regulates Wnt signaling via its armadillo repeat domain in a manner similar to β-catenin. To determine its role in tooth development, we performed Pkp1 knockdown experiments using ex vivo organ cultures and cell cultures. Loss of Pkp1 reduced the size of tooth germs and inhibited dental epithelial cell proliferation, which was stimulated by Wnt3a. Furthermore, transfected PKP1-emerald green fluorescent protein was translocated from the plasma membrane to the nucleus upon stimulation with Wnt3a and LiCl, which required the PKP1 N terminus (amino acids 161 to 270). Localization of PKP1, which is known as an adhesion-related desmosome component, shifted to the plasma membrane during ameloblast differentiation. In addition, Pkp1 knockdown disrupted the localization of Zona occludens 1 in tight junctions and inhibited ameloblast differentiation; the two proteins were shown to directly interact by immunoprecipitation. These results implicate the participation of PKP1 in early tooth morphogenesis as an effector of canonical Wnt signaling that controls ameloblast differentiation via regulation of the cell adhesion complex.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0152206PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4806907PMC
August 2016

Predisposing Factors for Orthodontic Mini-Implant Failure Defined by Bone Strains in Patient-Specific Finite Element Models.

Ann Biomed Eng 2016 10 16;44(10):2948-2956. Epub 2016 Mar 16.

Section of Orthodontics and Dentofacial Orthopedics, Faculty of Dental Science, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.

Factors responsible for the success or failure of orthodontic mini-implants (OMIs) in clinical settings are unclear. Failure of OMIs was found to be associated with increased maximum principal strain (MaxPN) when assessed using the subject-specific finite element (FE) modeling technique. The purpose of the present study was to identify factors that increase MaxPN and thereby predispose the OMI to failure. Using the FE method, MaxPN was calculated around 28 OMIs placed in orthodontic patients, 6 of which failed during the first 5 months. Sixteen potential risk factors related to patients or to OMI position were measured on computerized tomographic images or calculated in FE models. The impact of these factors on MaxPN was verified using regression analysis. Three factors were found to have significant nonlinear relationships with MaxPN: cortical bone quality, vertical angulation of the OMI, and proximity of the OMI to the tooth in the direction of force. In conclusion, failure of an OMI is a multifactorial problem, and position and angulation of the implant are among the affecting factors. Slight apical inclination and positioning at least 1 mm off the root in the direction of force may significantly decrease failure probability.
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http://dx.doi.org/10.1007/s10439-016-1584-8DOI Listing
October 2016