A lot of autoimmune diseases are known to develop in postmenopausal women. However, the mechanisms by which estrogen deficiency influences the onset or development of autoimmunity remain unclear. Sjögren's syndrome (SS) is characterized by a 9 : 1 ratio of women/men. In particular, almost patients with SS are postmenopausal women. Drastic change of estrogenic action in women has been discussed for a long time in the points of the phenotypes, functions and signaling pathways of immune cells and target cells in autoimmunity. Estrogen deficiency due to menopause influences the systemic homeostasis including immune system. Phonotypic changes of immune cells or dysfunction of target cells are associated with the onset or development of autoimmune diseases, such as SS. In this review article, the roles of estrogen were focused on to understand the pathogenesis of SS based on the previous data including our reports.

  Introduction : Dental calculus is a major risk factor for the accumulation of dental plaque, which leads to the progression of periodontitis. Dental calculus forms through the mineralization of dental plaque with the involvement of bacterial communities, and its formation may be influenced by the distinct environments of the supragingival and subgingival regions, similar to dental plaque. Additionally, calculus itself may affect periodontitis progression. However, no studies have examined the bacterial compositions and the differences between supragingival calculus (SUP) and subgingival calculus (SUB) in Japanese populations. This study aims to clarify and compare the bacterial communities and structures in SUP and SUB.

  Methods : SUP and SUB samples were collected from 31 patients. The bacterial communities were analyzed using 16S rDNA amplicon sequencing, differential abundance analysis, and network analysis.

  Results : While alpha diversity showed no significant differences between SUP and SUB, beta diversity analysis revealed distinct bacterial communities between the two groups. Aerobic bacteria dominated in SUP, whereas anaerobic bacteria were more prevalent in SUB. Corynebacterium matruchotii exhibited a high average relative abundance in both SUP and SUB. Mogibacterium timidum had a statistically significantly higher relative abundance in SUB compared to SUP and was strongly correlated with many bacterial taxa in the network of SUB.

  Conclusion : The bacterial communities in dental calculus are shaped by the specific environment in which they form, leading to differences between the supragingival and subgingival regions. C. matruchotii was a prominent bacterial taxon in both regions, while M. timidum played a central role in the subgingival region.

  Introduction : Post-treatment apical periodontitis (PoAP) represents an inflammatory condition of the periradicular tissue because of intracanal (re) infection after orthograde root canal treatment, whereas little is known about the etiological role of microbiota in PoAP. The purpose of this study was to investigate the diversity of microbiota among multiple intraradicular and extraradicular sites of a tooth associated with a PoAP lesion and to find out whether and how the diversity is related to several clinical parameters.

  Materials and Methods : Fifty-one microbiota samples from 12 patients with PoAP were collected according to 5 categories : granulation tissue, plaque on the extraradicular surface, dissected apex, root filling material, and cemental tear. Bacterial composition of a microbiota within each sample was investigated by sequencing a 16S rRNA gene library from bacterial DNA in the sample. The composition was compared between samples with several clinical parameters including the presence/absence of sinus tract and the lesion size as determined with the cone-beam computed tomography-periapical volume index (CBCT-PAVI).

  Results : The bacterial composition in each patient was either highly similar among sites or unique to each site. In the principal coordinate analysis plot, samples were clustered according to some of clinical parameters, regardless of the similarity and uniqueness of composition ; however, no bacterial phyla and genera showed clear relation to any clusters in terms of their abundance.

  Conclusion : The microbiota at intraradicular and extraradicular sites associated with the PoAP lesion was either homogenous or heterogenous among sites, and would be formed and change its composition under the surrounding clinical conditions.

  Introduction : Facial soft tissue morphological records are essential for the treatment planning and postoperative evaluation of facial deformities. In this study, we evaluated whether three-dimensional (3D) models of facial features reconstructed using photogrammetry software and smartphone-based image acquisition can be used in clinical practice.

  Materials and Methods : Photogrammetric 3D models of an inanimate object (a mannequin head) and human volunteers were reconstructed from smartphone recordings, and their trueness was evaluated using point-to-point measurements using a caliper and their precision by superimposing the 3D models. A trueness evaluation was performed by superimposing the CT data and 3D models for the mannequin head and patients.

  Results : The trueness of the point-to-point measurements was approximately 0.3% when measuring inanimate objects and approximately 0.5% when measuring humans  (volunteers). The trueness of the surface deviations was approximately 0.6mm when measuring inanimate objects and approximately 1mm when measuring humans (patients). The precision of the surface deviations between the photogrammetric 3D models was approximately 0.2mm when measuring inanimate objects and approximately 0.3mm when measuring humans (volunteers).

  Conclusion : The trueness and precision of the facial 3D models reconstructed using photogrammetry software and smartphone-based image acquisition were acceptable. Although technical stability and patient patience and cooperation are required, this method is considered sufficiently clinically applicable.

  Introduction : Periodontitis-associated fibroblasts (PAFs) have recently been identified in the tissues of periodontal disease and the interaction between the fibroblasts and epithelial cells has been reported to promote collagenolytic activity. However, the characteristics and genetic background of fibroblasts involved in peri-implantitis have not yet been clarified. In this study, we evaluated the collagen resolution activity and gene expression in peri-implantitis-associated fibroblasts (PIAFs) and investigated the effect of the inhibition of vascular endothelial growth factor (VEGF) /hepatocyte growth factor (HGF) signaling on PIAFs.

  Materials and Methods : Human connective tissue was collected from 17 patients during implant removal or peri-implant debridement. The epithelium was collected from one healthy patient during implant placement surgery. The collected tissues were digested and subsequently cultured three-dimensionally. Gene expression in PIAFs and non-PIAFs was evaluated using next-generation sequencing (NGS) analysis. VEGF/HGF inhibitors were applied to evaluate the effect on collagen degradation of PIAFs.

  Results : The 43 highly expressed genes in PIAFs compared to non-PIAFs, including those encoding VEGF/HGF signaling molecules. Inhibition of VEGF/HGF signaling significantly reduces collagen degradation in PIAFs.

  Conclusion : PIAFs significantly degrade collagen. However, the collagenolytic activity of PIAFs is inhibited by VEGF/HGF signaling inhibition. Further studies are required to identify the genetic background of PIAFs to elucidate the relationship between genetic variation and the pathological progression of peri-implantitis.

  Introduction : The Hippo signaling pathway plays a critical role in mediating mechanotransduction ; however, its specific role in orthodontic tooth movement (OTM) remains unclear. Therefore, we investigated the expression patterns of TEA domain family member 1 (TEAD1), a Hippo pathway transcription factor, in rat periodontal tissues during OTM and determined its role in osteoblast differentiation of periodontal ligament (PDL) cells.

  Materials and Methods : OTM was performed on 8-week-old male Sprague-Dawley rats for 1, 7, and 14 days (n=6 each). The expression levels of TEAD1, Yes-associated protein (YAP), transcriptional coactivator with PDZ binding motif  (TAZ), and runt-related transcription factor 2  (RUNX2)  in PDL cells were determined using immunohistochemical staining. In addition, Tead1 was silenced in PDL cells using small interfering RNA. Reverse transcription quantitative polymerase chain reaction, alkaline phosphatase staining, and 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide assay were used to evaluate the role of TEAD1 in the differentiation and proliferation of PDL cells.

  Results : On OTM day 7, the highest TEAD1, YAP, and TAZ expression was observed on the compression side of the PDL cells, whereas the highest RUNX2 expression was observed on the tension side. Tead1, Yap, and Taz mRNA levels were significantly increased after three days and gradually decreased after seven days of culture in osteogenic differentiation medium. Tead1 suppression significantly increased Runx2 mRNA levels and alkaline phosphatase activity and significantly decreased cell proliferation.

  Conclusions : The YAP/TAZ-TEAD1 axis may be involved in the regulation of osteoblast differentiation during the early stages of OTM.