Elsevier BV Acta Medica Okayama 1349-0079 68 1 2026 Roles of the aryl hydrocarbon receptor and its ligands in osteoclast differentiation and temporomandibular joint osteoarthritis 100726 EN Takashi Izawa Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Islamy Rahma Hutami Department of Orthodontics, Universitas Islam Sultan Agung Yuri Yoshikawa Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Gohji Kozaki Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yusaku Hamada Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yuki Namba Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Misa Taguchi Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Jiamin Chen Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Janvier Habumugisha Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Background: The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that plays an essential role in skeletal homeostasis. Increasing evidence indicates that AhR critically regulates osteoclast differentiation and activity, thereby influencing bone mass, bone resorption, and susceptibility to skeletal diseases. Although AhR has also been implicated in osteoblast-lineage cells, its regulatory roles in osteoclasts and immune cells are less well understood but are increasingly recognized as central to bone remodeling. In particular, AhR signaling modulates immune cell subsets relevant to bone metabolism and governs the differentiation of bone marrow-derived macrophages into osteoclasts. Highlight: This review summarizes the recent findings regarding the regulation of osteoclast differentiation by AhR and its ligands under both physiological and pathological conditions. Special emphasis is placed on the interaction between AhR and the RANKL signaling axis in osteoclasts, as well as on how exogenous and endogenous ligands, including benzo[a]pyrene (B[a]P) and 6-formylindolo[3,2-b]carbazole (FICZ), modulate bone resorption and subchondral bone remodeling in temporomandibular joint osteoarthritis. Furthermore, the role of macrophages as osteoclast progenitors and immunomodulators has been highlighted, positioning AhR as a critical intermediary that links environmental exposure, inflammation, and skeletal metabolism. Conclusion: In this review, we outlined the diverse functions of AhR signaling and its ligands in oral and temporomandibular joint osteoarthritis. AhR plays a central role in bone remodeling. The harmful exogenous ligand B[a]P generally promotes bone loss, whereas the endogenous ligand FICZ exerts protective actions. These insights highlight AhR as a key regulatory switch linking the skeletal and immune systems and as a promising therapeutic target for bone-destructive disorders. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 1880-6546 76 2 2026 Pharmaceutical agents targeting KATP channel modulate sweet taste sensitivity in mice 100082 EN Chika Sawai Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kuanyu Wang Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kengo Horie Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yoshihiro Mitoh Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hirotaka Ueda Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ryusuke Yoshida Department of Oral Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Sweet detection involves at least two mechanisms: a G-protein coupled sweet taste receptor (Tas1r2/Tas1r3) and glucose transporters. As in pancreatic β-cells, glucose transport may lead to closure of ATP-sensitive potassium (KATP) channels. Since expression of KATP channels in sweet taste cells has been reported, modulation of KATP channel activity would affect sweet taste sensitivity. Here, we examined the effect of glibenclamide (a KATP channel closer) and diazoxide (an opener) on mouse taste behavior. Glibenclamide selectively reduced taste sensitivity to glucose without affecting responses to sucrose or sucralose compared to insulin, suggesting selective impairment of the transporter-dependent pathway. In contrast, diazoxide broadly suppressed responses to all tested sweeteners, indicating a generalized effect on sweet detection. Neither drug altered responses to non-sweet taste. These findings suggest that pharmacological modulation of KATP channel differently influences sweet taste; closers reduce glucose sensitivity whereas openers attenuate response to multiple sweeteners. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 8756-3282 209 2026 PPy-coated wire actuators for micromechanostimulation of cells – identification of immediate-early responsive mechanoregulatory genes in osteoblasts 117914 EN Jiamin Chen Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Amaia B. Ortega-Santos Department of Physics, Chemistry and Biology (IFM), Linköping University Satoru Hayano Department of Orthodontics, Okayama University Hospital Ziyi Wang Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Jose G. Martinez Department of Physics, Chemistry and Biology (IFM), Linköping University Emilio Satoshi Hara Department of Advanced International and Information Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Edwin W.H. Jager Department of Physics, Chemistry and Biology (IFM), Linköping University Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Mechanotransduction, i.e., the conversion of mechanical cues into biochemical signals, is essential for bone development, remodeling, and adaptation. Although mechanical loading is known to regulate osteoblast function and bone homeostasis, dissecting the early and sustained mechanotransductive responses at the microscale remains challenging due to limitations of existing in vitro models. Here, we report the development and application of a mechanostimulation system comprising a polypyrrole (PPy)-based wire actuator that expands and contracts (4 μm in radius) upon electrical actuation and enables precise, localized micromechanical stimulation of a small number of cells within standard culture formats. Using this system, we applied short-term (30 min) cyclic (Cyc30) or static (Stat30), as well as prolonged (120 min) cyclic (Cyc120) stimulations to two osteoblast-like cells (MC3T3-E1 or KUSA-A1). Subsequent transcriptomic profiling and computational network analyses revealed that Cyc30 was not capable of inducing significant changes in mRNA expression, suggesting cellular adaptation to short-term cyclic loading. In contrast, Stat30 induced the upregulation of Fos, Btg2, Egr1, and Fosl1, all known genes associated with mechanotransduction, supporting the validity and reproducibility of our experimental mechanostimulation system. Notably, two long non-coding RNAs (B930036N10Rik and 5430431A17Rik) were identified for the first time as being upregulated in response to Stat30 stimuli. Among the differentially expressed genes (DEGs) upregulated by Cyc120 stimuli, Hmox1, a stress-inducible enzyme known for its roles in maintaining cellular homeostasis and promoting survival, was the only DEG repeatedly observed across the Cyc30/Cyc120 and Stat30/Cyc120 comparisons in both cell types, potentially emerging as a key stress-response gene under prolonged mechanical loading. Collectively, these results establish the PPy-based microactuator as a powerful tool for microscale mechanobiology, and provide molecular insight into immediate-early responsive transcriptional programs underlying osteoblastic mechanoadaptation conserved across different cell types. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 2688-4046 6 3 2026 PPy‐Coated Wire Actuators for the Micromechanostimulation of Cells: Fabrication and Characterization e202500639 EN Amaia B. Ortega‐Santos Sensor and Actuator Systems, Department of Physics Chemistry and Biology (IFM), Linköping University Satoru Hayano Department of Orthodontics, Okayama University Hospital Emilio Satoshi Hara Advanced Research Center for Oral and Craniofacial Sciences Dental School, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Jose G. Martínez Sensor and Actuator Systems, Department of Physics Chemistry and Biology (IFM), Linköping University Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Edwin W. H. Jager Sensor and Actuator Systems, Department of Physics Chemistry and Biology (IFM), Linköping University Cellular mechanotransduction signals play a crucial role in physiological and pathological conditions, including skeletal disorders. Although various systems exist to mechanically stimulate cultured cells, most are constrained by incubator incompatibility, limited physiological relevance, nonuniform stimulation, or complexity. The objective of this article is to develop and validate a compact, incubator-compatible tool capable of delivering localized and physiologically relevant mechanical stimulation to small cell populations. Here, we introduce a polypyrrole-based wire-shaped microactuator designed to induce localized mechanical stress to adjacent cells. These wire-shaped microactuators are biocompatible, easy-to-use, and compact for use within standard in vitro cell culture systems. Using a noncontact optical method, we characterize the actuation of polypyrrole-coated wires in an aqueous NaDBS electrolyte, showing radial expansion of 1.5–8 µm depending on the deposited polypyrrole film thickness, comparable to cellular dimensions. Next, the actuation is confirmed to be robust and stable to use in cell culture media at physiological temperature. To evaluate biological relevance, osteoblastic KUSA-A1 cells are mechanically stimulated inside the incubator and transcriptomic changes are assessed. Mechanical stimulation resulted in upregulation of genes previously associated with mechanotransduction, including Fos and Fosb. Additionally, several uncharacterized long noncoding RNAs are differentially expressed, suggesting potential novel players in the mechanotransduction pathway. No potential conflict of interest relevant to this article was reported.

Ovid Technologies (Wolters Kluwer Health) Acta Medica Okayama 2169-7574 14 2 2026 A Technique for Repositioning the Posteriorly Displaced Premaxilla Following Prior Repair of Complete Bilateral Cleft Lip e7467 EN Yuki Arimura Department of Oral and Maxillofacial Reconstructive Surgery, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Seiji Iida Department of Oral and Maxillofacial Reconstructive Surgery, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Aiko Hyodo Advanced Cleft Lip and Cleft Palate Center, Okayama University Hospital Ayaka Mikami Department of Oral and Maxillofacial Reconstructive Surgery, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Satoru Hayano Advanced Cleft Lip and Cleft Palate Center, Okayama University Hospital Fumiko Takemoto Advanced Cleft Lip and Cleft Palate Center, Okayama University Hospital Hiroshi Kamioka Advanced Cleft Lip and Cleft Palate Center, Okayama University Hospital It is well known that osteotomy of the premaxilla is an effective surgical procedure for the correction of a displaced premaxilla in patients with bilateral cleft lip and palate. In cases with a posteriorly displaced premaxilla, it is not easy to move the premaxilla forward because of scarring of the palatal mucosal attachment, narrowing of the adjacent maxillary segments, and the stable fixation of this bone segment after its movement. This fixation is also important in cases without secondary bone grafting. We propose a new method that combines osteotomy and a method such as bone distraction for cases with significant premaxilla displacement that are difficult to repair by osteotomy alone. A conventional orthodontic palatal expander was used as the distractor. The anterior arms were bent at the posterior part of the lingual side of the anterior teeth, and a resin base was attached to the arm parts. The posterior arms were bent and waxed onto the bands of both first molars. Supportive stainless steel wire arms, which are attached to the rest of the deciduous molars, stabilize the distractor. After the osteotomy of the premaxilla, distraction was performed at a rate of 1.0 mm per day, starting the day after surgery. Because the premaxilla of patients with bilateral cleft lip and palate has undergone multiple surgical interventions, the soft tissue is not mobile, making it impossible to guide the premaxilla to an ideal position in a single stage. However, this procedure, using this semirigid distractor, makes it possible to move the osteotomized premaxilla to the planned position with firm stability. No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 2221-3759 14 1 2026 The Influence of Fluidic Flow Stress on the Development of the Secondary Palate 9 EN Masayo Nagata Department of Orthodontics, Okayama University Hospital Satoru Hayano Department of Orthodontics, Okayama University Hospital Ziyi Wang Department of Molecular Biology and Biochemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Takahiro Kosami Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Craniofacial development is orchestrated by a finely regulated interplay of numerous genes and signaling pathways. Palatogenesis proceeds through a complex, stepwise process, in which endogenous mechanical stresses within tissues have been implicated. However, the impact of exogenous fluidic flow mechanical stress derived from maternal movement on palatal development remains unclear. In this study, we investigated the effect of exogenous fluidic flow mechanical stress on palatal morphogenesis, focusing on the horizontal outgrowth of palatal shelves after elevation. Palatal tissues dissected from mouse embryos were subjected to organ culture with or without mechanical loading (loaded and unloaded groups, respectively). Stress magnitude was quantified by calculating wave energy, and morphometric and molecular analyses were performed. Compared with the unloaded group, palatal shelves in the loaded group showed significant increases in thickness and volume, accompanied by enhanced cell proliferation, nuclear translocation of YAP and β-catenin, and upregulation of the osteogenic markers Osterix and Osteocalcin. No significant difference in apoptosis was observed. These findings indicate that exogenous mechanical stress promotes cell proliferation and osteogenic differentiation through the Hippo and WNT/β-catenin pathways in palate explants. Our results suggest that moderate maternal movement-induced mechanical stress contributes to normal palatogenesis, providing new insights into the mechanisms underlying cleft palate. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 1349-0079 68 1 2026 Dynamin 2 is involved in osteoblast migration by regulating the organization of F-actin 100720 EN Takumi Moriya Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University A. Surong Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Nanami Tatsumi Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroshi Yamada Department of Neuroscience, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Fumiko Takemoto Department of Orthodontics, Okayama University Hospital Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hirohiko Okamura Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Mika Ikegame Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Objectives: Dynamin, a GTPase that regulates membrane dynamics, has recently been implicated in actin cytoskeletal remodeling. This study aimed to elucidate the role of dynamin in osteoblast migration by examining the effects of dynamin inhibition on the localization and organization of F-actin and dynamin 2 in MC3T3-E1 cells. Methods: MC3T3-E1 cells were treated with dynamin inhibitors (Dyngo 4a and Dynole 34-2), and cell migration was assessed using a wound-healing assay. Fluorescent staining was performed to analyze the intracellular localization of F-actin and dynamin 2. Results: Dynamin inhibition significantly reduced the migration of MC3T3-E1 cells. Fluorescence analysis revealed a marked decrease in the accumulation and colocalization of F-actin and dynamin 2 at the protrusion edge. Additionally, dynamin inhibition suppressed the formation of lamellipodia and stress fibers while promoting the appearance of abnormal F-actin clusters in the cytoplasm. Conclusions: These findings suggest that dynamin plays an essential role in osteoblast migration by regulating actin cytoskeletal remodeling, particularly through the formation of lamellipodia and stress fibers. No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 1422-0067 26 19 2025 Critical Requirement of Senescence-Associated CCN3 Expression in CD44-Positive Stem Cells for Osteoarthritis Progression 9630 EN Janvier Habumugisha Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ryuichiro Okuda Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kazuki Hirose Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Miho Kuwahara Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ziyi Wang Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Mitsuaki Ono Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Satoshi Kubota Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takako Hattori Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Osteoarthritis (OA) is a degenerative joint disease characterized by progressive cartilage breakdown, synovial inflammation, and subchondral bone remodeling. Previous studies have shown that cellular communication network factor 3 (CCN3) expression increases with age in cartilage, and its overexpression promotes OA-like changes by inducing senescence-associated secretory phenotypes. This study aimed to investigate the effect of Ccn3 knockout (KO) on OA development using a murine OA model. Destabilization of the medial meniscus (DMM) surgery was performed in wild-type (WT) and Ccn3-KO mice. Histological scoring and staining were used to assess cartilage degeneration and proteoglycan loss. Gene and protein expressions of catabolic enzyme (Mmp9), hypertrophic chondrocyte marker (Col10a1), senescence marker, and cyclin-dependent kinase inhibitor 1A (Cdkn1a) were evaluated. Single-cell RNA sequencing (scRNA-seq) data from WT and Sox9-deficient cartilage were reanalyzed to identify Ccn3+ progenitor populations. Immunofluorescence staining assessed CD44 and Ki67 expression in articular cartilage. The effects of Ccn3 knockdown on IL-1β-induced Mmp13 and Adamts5 expression in chondrocytes were examined in vitro. Ccn3 KO mice exhibited reduced cartilage degradation and catabolic gene expression compared with WT mice post-DMM. scRNA-seq revealed enriched Ccn3-Cd44 double-positive cells in osteoblast progenitor, synovial mesenchymal stem cell, and mesenchymal stem cell clusters. Immunofluorescence showed increased CCN3+/CD44+ cells in femoral and tibial cartilage and meniscus. Ki67+ cells were significantly increased in DMM-treated Ccn3 KO cartilage, mostly CD44+. In vitro Ccn3 knockdown attenuated IL-1β-induced Mmp13 and Adamts5 expressions in chondrocytes. Ccn3 contributes to OA pathogenesis by promoting matrix degradation, inducing hypertrophic changes, and restricting progenitor cell proliferation, highlighting Ccn3 as a potential therapeutic target for OA. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 2045-2322 15 1 2025 Effect of mechanical stretching stimulation on maturation of human iPS cell-derived cardiomyocytes co-cultured with human gingival fibroblasts 30648 EN Mengxue Wang Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Harumi Idei Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Chen Wang Department of Nursing, School of Life and Health Sciences, HuZhou College Yin Liang Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yun Liu Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yusuke Matsuda Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ken Takahashi Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Keiji Naruse Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University In the realm of regenerative medicine, despite the various techniques available for inducing the differentiation of induced pluripotent stem (iPS) cells into cardiomyocytes, there remains a need to enhance the maturation of the cardiomyocytes. This study aimed to improve the differentiation and subsequent maturation of iPS-derived cardiomyocytes (iPS-CMs) by incorporating mechanical stretching. Human iPS cells were co-cultured with human gingival fibroblasts (HGF) on a polydimethylsiloxane (PDMS) stretch chamber, where mechanical stretching stimulation was applied during the induction of cardiomyocyte differentiation. The maturation of iPS-CMs was assessed using qRT-PCR, immunocytochemistry, transmission electron microscopy, calcium imaging and contractility comparisons. Results indicated significantly elevated gene expression levels of cardiomyocyte markers (cTnT) and the mesodermal marker (Nkx2.5) in the stretch group compared to the control group. Fluorescent immunocytochemical staining revealed the presence of cardiac marker proteins (cTnT and MYL2) in both groups, with higher protein expression in the stretch group. Additionally, structural maturation of iPS-CMs in the stretch group was notably better than in the control group. A significant increase in the contractility and calcium cycle of iPS-CMs was observed in the stretch group. These findings demonstrate that mechanical stretching stimulation enhances the maturation of iPS-CMs co-cultured with HGF. No potential conflict of interest relevant to this article was reported.

BMC Acta Medica Okayama 1472-6831 25 1 2025 Exploring the relationship between posture-dependent airway assessment in orthodontics: insights from kinetic MRI, cephalometric data, and three-dimensional MRI analysis 745 EN Naoki Oka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Janvier Habumugisha Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Masahiro Nakamura Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Tomoki Kataoka Division of Oral and Maxillofacial Surgery, Tottori University Atsuro Fujisawa Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Noriaki Kawanabe Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Takashi Izawa Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Background Previous studies have assessed the upper airway using various examination methods, such as cephalometric imaging and magnetic resonance imaging (MRI). However, there is a significant gap in the research regarding the relationship between these different imaging modalities. This study compares airway assessments using kinetic MRI and cephalometric scans, examining their correlation with three dimensional (3D) MRI data. Materials and methods Kinetic MRI, cephalometric scans, and 3D MRI of forty-seven participants were used in the present study. Airway areas and widths were measured at the retropalatal, retroglossal, and hypopharyngeal levels in both kinetic MRI and cephalometric scans. Airway volumes were calculated from 3D MRI data. Statistical analyses, including the Wilcoxon Signed Rank test, Spearman correlation, and multiple linear regression, were performed to evaluate the data and identify significant differences, correlations, and prediction models, respectively. Results Significant differences were found between kinetic MRI and cephalometric scans. Cephalometric data showed larger airway areas and widths compared to kinetic MRI measurements. Although both cephalometric and kinetic MRI showed a correlation with 3D MRI, kinetic MRI demonstrated stronger correlations with 3D MRI airway volumes than cephalometric scans. According to our linear regression model equations, RPA-Max (maximum retropalatal airway area) and RPA (retropalatal airway area) can elucidate variations in RPV (retropalatal airway volume). RGA-Med (median retroglossal airway area) and RGA-Min (minimum retroglossal airway area) can explain variations in RGV (retroglossal airway volume). HPA (hypopharyngeal airway area) and ULHPAW-Max (maximum upper limit hypopharyngeal airway width) account for variations in HPV (hypopharyngeal airway volume). Additionally, TA-Max (maximum total airway area) can account for variations in TPV (total pharyngeal airway volume).ConclusionBoth cephalometric data and kinetic MRI data showed correlations with 3D MRI data. The shared posture of kinetic MRI and 3D MRI led to stronger correlations between these two modalities. Although cephalometric data had fewer correlations with 3D MRI and predictors for 3D airway volume, they were still significant. Our study highlights the complementary nature of kinetic MRI and cephalometric imaging, as both provide valuable information for airway assessment and exhibit significant correlations with 3D MRI data. No potential conflict of interest relevant to this article was reported.

Nature Portfolio Acta Medica Okayama 2045-2322 13 1 2023 Bundling of collagen fibrils influences osteocyte network formation during bone modeling 22028 EN Mana Hashimoto Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Haruka Takahashi Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kaori Tabata-Okubo Department of Orthodontics, Okayama University Hospital Noriyuki Nagaoka Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School Kazuaki Tokunaga Nikon Corporation Haruka Matsumori Nikon Corporation Yoshihito Ishihara Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Masaru Kaku Division of Bio‑prosthodontics, Faculty of Dentistry and Graduate School of Medical and Dental Sciences, Niigata University Tadahiro Iimura Department of Pharmacology, Faculty and Graduate School of Dental Medicine, Hokkaido University Toru Hara Research Center for Structural Materials, National Institute for Materials Science Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Osteocytes form a cellular network by gap junctions between their cell processes. This network is important since intercellular communication via the network is essential for bone metabolism. However, the factors that influence the formation of this osteocyte network remain unknown. As the early stage of osteocyte network formation occurs on the bone surface, we observed a newly formed trabecular bone surface by orthogonal focused ion beam-scanning electron microscopy. The embedding late osteoblast processes tended to avoid bundled collagen fibrils and elongate into sparse collagen fibrils. Then, we examined whether the inhibition of bundling of collagen fibrils using a potent lysyl oxidase inhibitor, beta-aminopropionitrile (BAPN) changed the cellular network of the chick calvaria. The osteocyte shape of the control group was spindle-shape, while that of the BAPN group was sphere-shaped. In addition, the osteocyte processes of the control group were elongated vertically to the long axis of the cell body, whereas the osteocyte processes of the BAPN group were elongated radially. Therefore, it was suggested that the bundling of collagen fibrils influences normal osteocyte network formation during bone modeling. No potential conflict of interest relevant to this article was reported.

Informa UK Limited Acta Medica Okayama 2770-5781 81 1 2022 Improvement of anterior disc displacement on the mandibular deviated side after intraoral vertical ramus osteotomy in a patient with facial asymmetry: a case report 58 67 EN Hirotaka Ueda Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Naoki Oka Department of Orthodontics, Okayama University Hospital Tsuyoshi Shimo Division of Reconstructive Surgery for Oral and Maxillofacial Region, Department of Human Biology and Pathophysiology, School of Dentistry, Health Sciences University of Hokkaido Akira Sasaki Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takashi Yamashiro Department of Orthodontics and Dentofacial Orthopedics, Osaka University Graduate School of Dentistry Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Purpose: We present the orthognathic treatment of an adult skeletal Class III patient with facial asymmetry, mandibular rightward deviation, and anterior disc displacement without reduction (ADDwoR) at the right temporomandibular joint (TMJ) by intraoral vertical ramus osteotomy (IVRO). Materials and methods: The patient was a 23-year-old man with complaints of mandibular deviation and crowded lower anterior teeth, resulting in facial asymmetry. The maxillary position was normal with protrusion and rightward deviation of the mandible. There was no cant of the maxilla. He experienced pain in the right TMJ during mastication, and Magnetic resonance imaging (MRI) revealed an ADDwoR on the right side. The patient was diagnosed with Class III malocclusion, skeletal Class III prognathism with mandibular deviation, and ADDwoR on the right side. Orthognathic surgery was proposed for jaw deformity, and IVRO was performed to correct mandibular deviation. Results: One year and 2 months after treatment onset, IVRO was performed with differential setback: 2 mm on the right and 8 mm on the left side of the mandible. The midline of the lower dentition was rotated by 6 mm to coincide with the facial midline. Symptoms of temporomandibular disorders were not observed post-operatively. Active-treatment period was for 31 months. MRI findings showed improvement in anterior disc displacement on the right side during the post-retention. Conclusion: In the case of facial asymmetry with anterior disc displacement on the mandibular deviated side, IVRO was suggested to have a potential effect on the positional relationship between the mandibular head and temporomandibular disc. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 2050-750X 11 3 2022 Important roles of odontoblast membrane phospholipids in early dentin mineralization 657 666 EN Risa Anada Department of Biomaterials, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Emilio Satoshi Hara Department of Biomaterials, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Noriyuki Nagaoka Advanced Research Center for Oral and Craniofacial Sciences, Dental School, Okayama University Masahiro Okada Department of Biomaterials, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Takuya Matsumoto Department of Biomaterials, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University The objective of this study was to first identify the timing and location of early mineralization of mouse first molar, and subsequently, to characterize the nucleation site for mineral formation in dentin from a materials science viewpoint and evaluate the effect of environmental cues (pH) affecting early dentin formation. Early dentin mineralization in mouse first molars began in the buccal central cusp on post-natal day 0 (P0), and was first hypothesized to involve collagen fibers. However, elemental mapping indicated the co-localization of phospholipids with collagen fibers in the early mineralization area. Co-localization of phosphatidylserine and annexin V, a functional protein that binds to plasma membrane phospholipids, indicated that phospholipids in the pre-dentin matrix were derived from the plasma membrane. A 3-dimensional in vitro biomimetic mineralization assay confirmed that phospholipids from the plasma membrane are critical factors initiating mineralization. Additionally, the direct measurement of the tooth germ pH, indicated it to be alkaline. The alkaline environment markedly enhanced the mineralization of cell membrane phospholipids. These results indicate that cell membrane phospholipids are nucleation sites for mineral formation, and could be important materials for bottom-up approaches aiming for rapid and more complex fabrication of dentin-like structures. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1447-6959 2023 Mechanical stretching determines the orientation of osteoblast migration and cell division EN Fumiko Takemoto Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yoko Uchida-Fukuhara Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Hirohiko Okamura Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Mika Ikegame Department of Oral Morphology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Osteoblasts alignment and migration are involved in the directional formation of bone matrix and bone remodeling. Many studies have demonstrated that mechanical stretching controls osteoblast morphology and alignment. However, little is known about its effects on osteoblast migration. Here, we investigated changes in the morphology and migration of preosteoblastic MC3T3-E1 cells after the removal of continuous or cyclic stretching. Actin staining and time-lapse recording were performed after stretching removal. The continuous and cyclic groups showed parallel and perpendicular alignment to the stretch direction, respectively. A more elongated cell morphology was observed in the cyclic group than in the continuous group. In both stretch groups, the cells migrated in a direction roughly consistent with the cell alignment. Compared to the other groups, the cells in the cyclic group showed an increased migration velocity and were almost divided in the same direction as the alignment. To summarize, our study showed that mechanical stretching changed cell alignment and morphology in osteoblasts, which affected the direction of migration and cell division, and velocity of migration. These results suggest that mechanical stimulation may modulate the direction of bone tissue formation by inducing the directional migration and cell division of osteoblasts. No potential conflict of interest relevant to this article was reported.

Taylor and Francis Acta Medica Okayama 1468-6996 24 1 2023 Electrochemical control of bone microstructure on electroactive surfaces for modulation of stem cells and bone tissue engineering 2183710 EN Danfeng Cao Sensor and Actuator Systems, Department of Physics, Chemistry and Biology (IFM), Linköping University Jose G. Martinez Sensor and Actuator Systems, Department of Physics, Chemistry and Biology (IFM), Linköping University Risa Anada Advanced Research Center for Oral and Craniofacial Sciences Dental School, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Emilio Satoshi Hara Advanced Research Center for Oral and Craniofacial Sciences Dental School, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Edwin W. H. Jager Sensor and Actuator Systems, Department of Physics, Chemistry and Biology (IFM), Linköping University Controlling stem cell behavior at the material interface is crucial for the development of novel technologies in stem cell biology and regenerative medicine. The composition and presentation of bio-factors on a surface strongly influence the activity of stem cells. Herein, we designed an electroactive surface that mimics the initial process of trabecular bone formation, by immobilizing chondrocyte-derived plasma membrane nanofragments (PMNFs) on its surface for rapid mineralization within 2 days. Moreover, the electroactive surface was based on the conducting polymer polypyrrole (PPy), which enabled dynamic control of the presentation of PMNFs on the surface via electrochemical redox switching, further resulting in the formation of bone minerals with different morphologies. Furthermore, bone minerals with contrasting surface morphologies had differential effects on the differentiation of human bone marrow-derived stem cells (hBMSCs) cultured on the surface. Together, this electroactive surface showed multifunctional characteristics, not only allowing dynamic control of PMNF presentation but also promoting the formation of bone minerals with different morphologies within 2 days. This electroactive substrate could be valuable for more precise control of stem cell growth and differentiation, and further development of more suitable microenvironments containing bone apatite for housing a bone marrow stem cell niche, such as biochips/bone-on-chips. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 77 1 2023 Treatment of Severe Open Bite Malocclusion with Four-Piece Segmental Horseshoe Le Fort I Osteotomy 97 104 EN Mitsuhiro Hoshijima Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Naoki Oka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tatsushi Matsumura Department of Oral and Maxillofacial Surgery, Wakayama Medical University Seiji Iida Department of Oral and Maxillofacial Reconstructive Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Case Report 10.18926/AMO/64369 Appropriate operations in severe anterior open bite (AOB) cases are extremely complicated to perform because of the multiple surgical procedures involved, the difficulty of predicting posttreatment aesthetics, and the high relapse rate. We herein report a 16-year-old girl with skeletal Class II, severe AOB malocclusion, and crowding with short roots, and aesthetic and functional problems. Four-piece segmental Le Fort I osteotomy with horseshoe osteotomy was performed for maxillary intrusion, and bilateral sagittal split ramus osteotomy (SSRO) and genioplasty were performed for mandibular advancement. The malocclusion and skeletal deformity were significantly improved by the surgical orthodontic treatment. Functional and aesthetic occlusion with an improved facial profile was established, and no further root shortening was observed. Acceptable occlusion and dentition were maintained after a two-year retention period. This strategy of surgical orthodontic treatment with a complicated operative procedure might be effective for correcting certain severe AOB malocclusion cases. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1320-5463 2021 2021 Investigation of the molecular causes underlying physical abnormalities in Diamond‐Blackfan anemia patients with RPL5 haploinsufficiency 1 11 EN Yuko Fukui Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Satoru Hayano Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Noriaki Kawanabe Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Ziyi Wang Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Akira Shimada Department of Pediatric Hematology/Oncology Okayama University Hospital Megumu K. Saito Department of Clinical Application, Center for iPS Cell Research and Application Kyoto University Isao Asaka Department of Fundamental Cell Technology, Center for iPS Cell Research and Application Kyoto University Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University Diamond-Blackfan anemia (DBA) is a genetic disorder caused by mutations in genes encoding ribosomal proteins and characterized by erythroid aplasia and various physical abnormalities. Although accumulating evidence suggests that defective ribosome biogenesis leads to p53-mediated apoptosis in erythroid progenitor cells, little is known regarding the underlying causes of the physical abnormalities. In this study, we established induced pluripotent stem cells from a DBA patient with RPL5 haploinsufficiency. These cells retained the ability to differentiate into osteoblasts and chondrocytes. However, RPL5 haploinsufficiency impaired the production of mucins and increased apoptosis in differentiated chondrocytes. Increased expression of the pro-apoptotic genes BAX and CASP9 further indicated that RPL5 haploinsufficiency triggered p53-mediated apoptosis in chondrocytes. MDM2, the primary negative regulator of p53, plays a crucial role in erythroid aplasia in DBA patient. We found the phosphorylation level of MDM2 was significantly decreased in RPL5 haploinsufficient chondrocytes. In stark contrast, we found no evidence that RPL5 haploinsufficiency impaired osteogenesis. Collectively, our data support a model in which RPL5 haploinsufficiency specifically induces p53-mediated apoptosis in chondrocytes through MDM2 inhibition, which leads to physical abnormalities in DBA patients. No potential conflict of interest relevant to this article was reported.

Nature Portfolio Acta Medica Okayama 2045-2322 11 1 2021 Roles for B[a]P and FICZ in subchondral bone metabolism and experimental temporomandibular joint osteoarthritis via the AhR/Cyp1a1 signaling axis 14927 EN Yuri Yoshikawa Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Takashi Izawa Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yusaku Hamada Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiroko Takenaga Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ziyi Wang Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Naozumi Ishimaru Department of Oral Molecular Pathology, Tokushima University Graduate School of Biomedical Sciences Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Bone loss due to smoking represents a major risk factor for fractures and bone osteoporosis. Signaling through the aryl hydrocarbon receptor (AhR) and its ligands contributes to both bone homeostasis and inflammatory diseases. It remains unclear whether the same AhR signaling axis affects the temporomandibular joint (TMJ). The aim of this study was to investigate possible mechanisms which mediate bone loss in the TMJ due to smoking. In particular, whether benzo[a]pyrene (B[a]P), a carcinogen of tobacco smoke, induces expression of the AhR target gene, Cyp1a1, in mandibular condyles. Possible functions of an endogenous ligand of FICZ, were also investigated in a TMJ-osteoarthritis (OA) mouse model. B[a]P was administered orally to wild-type and AhR(-/-) mice and bone metabolism was subsequently examined. TMJ-OA was induced in wild-type mice with forceful opening of the mouth. Therapeutic functions of FICZ were detected with mu CT and histology. Exposure to B[a]P accelerated bone loss in the mandibular subchondral bone. This bone loss manifested with osteoclastic bone resorption and upregulated expression of Cyp1a1 in an AhR-dependent manner. In a mouse model of TMJ-OA, FICZ exhibited a dose-dependent rescue of mandibular subchondral bone loss by repressing osteoclast activity. Meanwhile, in vitro, pre-treatment with FICZ reduced RANKL-mediated osteoclastogenesis. B[a]P regulates mandibular subchondral bone metabolism via the Cyp1a1. The AhR ligand, FICZ, can prevent TMJ-OA by regulating osteoclast differentiation. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 75 2 2021 Camouflage Treatment for Skeletal Maxillary Protrusion and Lateral Deviation with Classic-Type Ehlers-Danlos Syndrome 205 212 EN Mitsuhiro Hoshijima Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Noriaki Kawanabe Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Seiji Iida Department of Oral and Maxillofacial Reconstructive Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takashi Yamashiro Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Case Report 10.18926/AMO/61902 We herein report the case of a 19-year-old female with a transverse discrepancy, skeletal Class II malocclusion, severe crowding with concerns of classic-type Ehlers-Danlos syndrome (EDS), aesthetics problems and functional problems. The main characteristics of classic EDS are loose-jointedness and fragile, easily bruised skin that heals with peculiar “cigarette-paper” scars. The anteroposterior and transverse skeletal discrepancies can generally be resolved by maxilla repositioning and mandibular advancement surgery following pre-surgical orthodontic treatment. However, this patient was treated with orthodontic camouflage but not orthognathic surgery because of the risks of skin bruising, poor healing and a temporomandibular disorder. A satisfactory dental appearance and occlusion were achieved after camouflage treatment with orthodontic anchor screws and the use of Class II elastics, including the preservation of the stomatognathic functions. Acceptable occlusion and dentition were maintained after a two-year retention period. This treatment strategy of orthodontic camouflage using temporary anchorage, such as anchor screws and Class II elastics, may be a viable treatment option for skeletal malocclusion patients with EDS. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 0021-9541 2021 RFX1‐mediated CCN3 induction that may support chondrocyte survival under starved conditions EN Tomomi Mizukawa Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takashi Nishida Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Sho Akashi Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Okayama Japan Kazumi Kawata Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Okayama Japan Sumire Kikuchi Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Okayama Japan Harumi Kawaki Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences Okayama Japan Masaharu Takigawa Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Satoshi Kubota Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Cellular communication network factor (CCN) family members are multifunctional matricellular proteins that manipulate and integrate extracellular signals. In our previous studies investigating the role of CCN family members in cellular metabolism, we found three members that might be under the regulation of energy metabolism. In this study, we confirmed that CCN2 and CCN3 are the only members that are tightly regulated by glycolysis in human chondrocytic cells. Interestingly, CCN3 was induced under a variety of impaired glycolytic conditions. This CCN3 induction was also observed in two breast cancer cell lines with a distinct phenotype, suggesting a basic role of CCN3 in cellular metabolism. Reporter gene assays indicated a transcriptional regulation mediated by an enhancer in the proximal promoter region. As a result of analyses in silico, we specified regulatory factor binding to the X‐box 1 (RFX1) as a candidate that mediated the transcriptional activation by impaired glycolysis. Indeed, the inhibition of glycolysis induced the expression of RFX1, and RFX1 silencing nullified the CCN3 induction by impaired glycolysis. Subsequent experiments with an anti‐CCN3 antibody indicated that CCN3 supported the survival of chondrocytes under impaired glycolysis. Consistent with these findings in vitro, abundant CCN3 production by chondrocytes in the deep zones of developing epiphysial cartilage, which are located far away from the synovial fluid, was confirmed in vivo. Our present study uncovered that RFX1 is the mediator that enables CCN3 induction upon cellular starvation, which may eventually assist chondrocytes in retaining their viability, even when there is an energy supply shortage. No potential conflict of interest relevant to this article was reported.

PeerJ Acta Medica Okayama 2167-8359 8 2020 Loading history changes the morphology and compressive force-induced expression of receptor activator of nuclear factor kappa B ligand/osteoprotegerin in MLO-Y4 osteocytes e10244 EN Ziyi Wang Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Yao Weng Department of Oral Morphology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Yoshihito Ishihara Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Naoya Odagaki Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Ei Ei Hsu Hlaing Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Takashi Izawa Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Hirohiko Okamura Department of Oral Morphology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Background In this study, we investigated the effect of the mechanical loading history on the expression of receptor activator of nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) in MLO-Y4 osteocyte-like cells. Methods Three hours after MLO-Y4 osteocytes were seeded, a continuous compressive force (CCF) of 31 dynes/cm2 with or without additional CCF (32 dynes/cm2) was loaded onto the osteocytes. After 36 h, the additional CCF (loading history) was removed for a recovery period of 10 h. The expression of RANKL, OPG, RANKL/OPG ratio, cell numbers, viability and morphology were time-dependently examined at 0, 3, 6 and 10 h. Then, the same additional CCF was applied again for 1 h to all osteocytes with or without the gap junction inhibitor to examine the expression of RANKL, OPG, the RANKL/OPG ratio and other genes that essential to characterize the phenotype of MLO-Y4 cells. Fluorescence recovery after photobleaching technique was also applied to test the differences of gap-junctional intercellular communications (GJIC) among MLO-Y4 cells. Results The expression of RANKL and OPG by MLO-Y4 osteocytes without a loading history was dramatically decreased and increased, respectively, in response to the 1-h loading of additional weight. However, the expression of RANKL, OPG and the RANKL/OPG ratio were maintained at the same level as in the control group in the MLO-Y4 osteocytes with a loading history but without gap junction inhibitor treatment. Treatment of loading history significantly changed the capacity of GJIC and protein expression of connexin 43 (Cx43) but not the mRNA expression of Cx43. No significant difference was observed in the cell number or viability between the MLO-Y4 osteocyte-like cells with and without a loading history or among different time checkpoints during the recovery period. The cell morphology showed significant changes and was correlated with the expression of OPG, Gja1 and Dmp1 during the recovery period. Conclusion Our findings indicated that the compressive force-induced changes in the RANKL/OPG expression could be habituated within at least 11 h by 36-h CCF exposure. GJIC and cell morphology may play roles in response to loading history in MLO-Y4 osteocyte-like cells. No potential conflict of interest relevant to this article was reported.

Springer Acta Medica Okayama 0914-8779 39 2020 Changes in the intra- and peri-cellular sclerostin distribution in lacuno-canalicular system induced by mechanical unloading 148 159 EN Ryuta Osumi Department of Orthodontics, Okayama University Hospital Ziyi Wang Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshihito Ishihara Department of Orthodontics, Okayama University Hospital Naoya Odagaki Department of Orthodontics, Okayama University Hospital Tadahiro Iimura Department of Pharmacology, Graduate School of Dental Medicine, Hokkaido University Hiroshi Kamioka Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Introduction Mechanical stimuli regulate Sclerostin (Scl), a negative regulator of bone formation, expression in osteocytes. However, the detailed Scl distribution in osteocytes in response to mechanical unloading remains unclear. Materials and methods Twelve-week-old male rats were used. The sciatic and femoral nerves on the right side were excised as mechanical unloading treatment. A sham operation was performed on the left side. One week after neurotrauma, the bone density of the femora was evaluated by peripheral quantitative computed tomography, and immunofluorescence was performed in coronal sections of the femoral diaphysis. The mean fluorescence intensity and fluorescent profile of Scl from the marrow to the periosteal side were analyzed to estimate the Scl expression and determine to which side (marrow or periosteal) the Scl prefers to distribute in response to mechanical unloading. The most sensitive region indicated by the immunofluorescence results was further investigated by transmission electron microscopy (TEM) with immunogold staining to show the Scl expression changes in different subcellular structures. Results In femur distal metaphysis, neurotrauma-induced mechanical unloading significantly decreased the bone density, made the distribution of Scl closer to the marrow on the anterior and medial side, and increased the Scl expression only on the lateral side. TEM findings showed that only the expression of Scl in canaliculi was increased by mechanical unloading. Conclusions Our results showed that even short-term mechanical unloading is enough to decrease bone density, and mechanical unloading not only regulated the Scl expression but also changed the Scl distribution in both the osteocyte network and subcellular structures. No potential conflict of interest relevant to this article was reported.

BMC Acta Medica Okayama 1746-160X 16 1 2020 Occlusal reconstruction of a patient with ameloblastoma ablation using alveolar distraction osteogenesis: a case report 12 EN Yoshihito Ishihara Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hikaru Arakawa Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine,Dentistry and Pharmaceutical Sciences Akiyoshi Nishiyama Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine Dentistry, and Pharmaceutical Sciences Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Background Ameloblastoma is one of the most common benign odontogenic neoplasms. Its surgical excision has the potential to lead to postoperative malocclusion. In this case report, we describe the successful interdisciplinary orthodontic treatment of a patient with ameloblastoma who underwent marginal mandibulectomy. Case presentation A woman of 20-year-old was diagnosed with ameloblastoma, and underwent marginal mandibulectomy when she was 8 years of age. She had an excessive overjet (11.5 mm) and a mild open bite (- 1.5 mm) with a severely resorbed atrophic edentulous ridge in the area around the mandibular left lateral incisor, canine and first premolar. An alveolar bone defect associated with tumor resection was regenerated by vertical distraction osteogenesis (DO). Subsequently, 3 dental implants were placed into the reconstructed mandible. Orthodontic treatment using implant-anchored mechanics provided a proper facial profile with significantly improved occlusal function. The occlusion appeared stable for a 7-year retention period. Conclusions These results suggest that surgically assisted and implant anchored-orthodontic approaches might be effective for the correction of such malocclusions. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1422-0067 21 8 2020 Roles of Interaction between CCN2 and Rab14 in Aggrecan Production by Chondrocytes EN Mitsuhiro Hoshijima Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takako Hattori Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Eriko Aoyama Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School/Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takashi Nishida Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Satoshi Kubota Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masaharu Takigawa Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School/Graduate School of Medicine, Dentistry and Pharmaceutical Sciences To identify proteins that cooperate with cellular communication network factor 2 (CCN2), we carried out GAL4-based yeast two-hybrid screening using a cDNA library derived from the chondrocytic cell line HCS-2/8. Rab14 GTPase (Rab14) polypeptide was selected as a CCN2-interactive protein. The interaction between CCN2 and Rab14 in HCS-2/8 cells was confirmed using the in situ proximity ligation assay. We also found that CCN2 interacted with Rab14 through its IGFBP-like domain among the four domains in CCN2 protein. To detect the colocalization between CCN2 and Rab14 in the cells in detail, CCN2, wild-type Rab14 (Rab14WT), a constitutive active form (Rab14CA), and a dominant negative form (Rab14DN) of Rab14 were overexpressed in monkey kidney-tissue derived COS7 cells. Ectopically overexpressed Rab14 showed a diffuse cytosolic distribution in COS7 cells; however, when Rab14WT was overexpressed with CCN2, the Rab14WT distribution changed to dots that were evenly distributed within the cytosol, and both Rab14 and CCN2 showed clear colocalization. When Rab14CA was overexpressed with CCN2, Rab14CA and CCN2 also showed good localization as dots, but their distribution was more widespread within cytosol. The coexpression of Rab14DN and CCN2 also showed a dotted codistribution but was more concentrated in the perinuclear area. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis revealed that the reduction in RAB14 or CCN2 mRNA by their respective siRNA significantly enhanced the expression of ER stress markers, BIP and CHOP mRNA in HCS-2/8 chondrocytic cells, suggesting that ER and Golgi stress were induced by the inhibition of membrane vesicle transfer via the suppression of CCN2 or Rab14. Moreover, to study the effect of the interaction between CCN2 and its interactive protein Rab14 on proteoglycan synthesis, we overexpressed Rab14WT or Rab14CA or Rab14DN in HCS-2/8 cells and found that the overexpression of Rab14DN decreased the extracellular proteoglycan accumulation more than the overexpression of Rab14WT/CA did in the chondrocytic cells. These results suggest that intracellular CCN2 is associated with Rab14 on proteoglycan-containing vesicles during their transport from the Golgi apparatus to endosomes in chondrocytes and that this association may play a role in proteoglycan secretion by chondrocytes. No potential conflict of interest relevant to this article was reported.

Federation of American Society of Experimental Biology Acta Medica Okayama 08926638 33 9 2019 Role of intracellular Ca2+–based mechanotransduction of human periodontal ligament fibroblasts 10409 10424 EN Ei Ei Hsu Hlaing Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Yoshihito Ishihara Department of Orthodontics, Okayama University Hospital Ziyi Wang Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Naoya Odagaki Department of Orthodontics, Okayama University Hospital Hiroshi Kamioka Department of Orthodontics and Dentofacial Orthopedics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Human periodontal ligament (hPDL) fibroblasts are thought to receive mechanical stress (MS) produced by orthodontic tooth movement, thereby regulating alveolar bone remodeling. However, the role of intracellular calcium ([Ca2+]i)‐based mechanotransduction is not fully understood. We explored the MS‐induced [Ca2+]i responses both in isolated hPDL fibroblasts and in intact hPDL tissue and investigated its possible role in alveolar bone remodeling. hPDL fibroblasts were obtained from healthy donors' premolars that had been extracted for orthodontic reasons. The oscillatory [Ca2+]i activity induced by static compressive force was measured by a live‐cell Ca2+ imaging system and evaluated by several feature extraction method. The spatial pattern of cell‐cell communication was investigated by Moran's I , an index of spatial autocorrelation and the gap junction (GJ) inhibitor. The Ca2+‐transporting ionophore A23187 was used to further investigate the role of [Ca2+]i up‐regulation in hPDL cell behavior. hPDL fibroblasts displayed autonomous [Ca2+]i responses. Compressive MS activated this autonomous responsive behavior with an increased percentage of responsive cells both in vitro and ex vivo . The integration, variance, maximum amplitude, waveform length, and index J in the [Ca2+]i responses were also significantly increased, whereas the mean power frequency was attenuated in response to MS. The increased Moran's I after MS indicated that MS might affect the pattern of cell‐cell communication via GJs. Similar to the findings of MS‐mediated regulation, the A23187‐mediated [Ca2+]i uptake resulted in the up‐regulation of receptor activator of NF‐κB ligand (Rankl) and Sost along with increased sclerostin immunoreactivity, suggesting that [Ca2+]i signaling networks may be involved in bone remodeling. In addition, A23187‐treated hPDL fibroblasts also showed the suppression of osteogenic differentiation and mineralization. Our findings suggest that augmented MS‐mediated [Ca2+]i oscillations in hPDL fibroblasts enhance the production and release of bone regulatory signals via Rankl/Osteoprotegerin and the canonical Wnt/β‐catenin pathway as an early process in tooth movement–initiated alveolar bone remodeling.—Ei Hsu Hlaing, E., Ishihara, Y., Wang, Z., Odagaki, N., Kamioka, H. Role of intracellular Ca2+‐based mechanotransduction of human periodontal ligament fibroblasts. FASEB J. 33, 10409–10424 (2019). No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1549-3296 107 5 2019 Biomimetic mineralization using matrix vesicle nanofragments 1021 1030 EN Yosuke Kunitomi Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Emilio Satoshi Hara Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masahiro Okada Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Noriyuki Nagaoka Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takuo Kuboki Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takayoshi Nakano Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takuya Matsumoto Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences In vitro synthesis of bone tissue has been paid attention in recent years; however, current methods to fabricate bone tissue are still ineffective due to some remaining gaps in the understanding of real in vivo bone formation process, and application of the knowledge in bone synthesis. Therefore, the objectives of this study were first, to perform a systematic and ultrastructural investigation of the initial mineral formation during intramembranous ossification of mouse calvaria from a material scientists' viewpoint, and to develop novel mineralization methods based on the in vivo findings. First, the very initial mineral deposition was found to occur at embryonic day E14.0 in mouse calvaria. Analysis of the initial bone formation process showed that it involved the following distinct steps: collagen secretion, matrix vesicle (MV) release, MV mineralization, MV rupture, and collagen fiber mineralization. Next, we performed in vitro mineralization experiments using MVs and hydrogel scaffolds. Intact MVs embedded in collagen gel did not mineralize, whereas, interestingly, MV nanofragments obtained by ultrasonication could promote rapid mineralization. These results indicate that mechanically ruptured MV membrane can be a promising material for in vitro bone tissue synthesis. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 71 5 2017 Modification of Dentofacial Growth Associated with Goldenhar Syndrome 437 443 EN Ei Ei Hsu Hlaing Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshihito Ishihara Department of Orthodontics, Okayama University Hospital Chikako Hara Department of Orthodontics, Okayama University Hospital Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Case Report 10.18926/AMO/55443 The rare developmental defect, Goldenhar syndrome is characterized by complex craniofacial and dentofacial anomalies. Here we describe the successful orthodontic treatment of a 5-year-old Japanese Goldenhar syndrome patient with mild facial asymmetry, right microtia, right-side hearing loss, and tongue-thrusting by a modification of dentofacial growth using a non-surgical orthopedic treatment approach. Improvement of the vertical discrepancies on the affected side and canted occlusal plane as well as mandibular deviation were achieved with a functional orthopaedic approach. Stable and acceptable occlusion were obtained over the 32-month post-retention period. A non-surgical orthodontic treatment approach offers satisfactory facial aesthetic outcomes in Goldenhar syndrome. No potential conflict of interest relevant to this article was reported.

Taylor & Francis Acta Medica Okayama 1439-7595 26 6 2016 Involvement of multiple CCN family members in platelets that support regeneration of joint tissues 940 949 EN Chikako Hara Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Satoshi Kubota Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takashi Nishida Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Miki Hiasa Department of Membrane Biochemistry , Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takako Hattori Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Eriko Aoyama Advanced Research Center for Oral and Craniofacial Sciences , Okayama University Dental School Yoshinori Moriyama Department of Membrane Biochemistry , Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiroshi Kamioka Department of Orthodontics , Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masaharu Takigawa Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences OBJECTIVES: Platelet-rich plasma (PRP) has been widely used to enhance the regeneration of damaged joint tissues, such as osteoarthritic and rheumatoid arthritic cartilage. The aim of this study is to clarify the involvement of all of the CCN family proteins that are crucially associated with joint tissue regeneration. METHODS: Cyr61-CTGF-NOV (CCN) family proteins in human platelets and megakaryocytic cells were comprehensively analyzed by Western blotting analysis. Production of CCN family proteins in megakaryocytes in vivo was confirmed by immunofluorescence analysis of mouse bone marrow cells. Effects of CCN family proteins found in platelets on chondrocytes were evaluated by using human chondrocytic HCS-2/8 cells. RESULTS: Inclusion of CCN2, a mesenchymal tissue regenerator, was confirmed. Of note, CCN3, which counteracts CCN2, was newly found to be encapsulated in platelets. Interestingly, these two family members were not detectable in megakaryocytic cells, but their external origins were suggested. Furthermore, we found for the first time CCN5 and CCN1 that inhibits ADAMTS4 in both platelets and megakaryocytes. Finally, application of a CCN family cocktail mimicking platelets onto HCS-2/8 cells enhanced their chondrocytic phenotype. CONCLUSIONS: Multiple inclusion of CCN1, 2 and 3 in platelets was clarified, which supports the harmonized regenerative potential of PRP in joint therapeutics. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 70 5 2016 A Single-center, Open-label, Randomized Controlled Clinical Trial to Evaluate the Efficacy and Safety of the Indirect Bonding Technique 413 416 EN Takashi Murakami Department of Orthodontics, Okayama University Hospital Noriaki Kawanabe Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomoki Kataoka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Mitsuhiro Hoshijima Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiroki Komori Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Atsuro Fujisawa Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiroshi Kamioka Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Clinical Study Protocols 10.18926/AMO/54604 Although accurate bracket placement is essential for orthodontic treatment, many practitioners apply brackets indiscriminately with direct or indirect bonding techniques. Nonetheless, there have been few prospective clinical comparisons of the 2 techniques. We will therefore conduct a single-center, randomized control trial in 100 patients aged ≥12 years and diagnosed with malocclusion. All patients will receive orthodontic treatment using brackets with direct or indirect bonding techniques. The primary endpoints will be the total treatment time, occlusal index, discomfort at bonding, and oral hygiene after bonding. This study will clarify whether indirect bonding can improve the efficiency of orthodontic treatment. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 69 3 2015 Maxillary Advancement for Unilateral Crossbite in a Patient with Sleep Apnea Syndrome 177 182 EN Mitsuhiro Hoshijima Tadashi Honjo Norifumi Moritani Seiji Iida Takashi Yamashiro Hiroshi Kamioka Case Report 10.18926/AMO/53525 This article reports the case of a 44-year-old male with skeletal Class III, Angle Class III malocclusion and unilateral crossbite with concerns about obstructive sleep apnea syndrome (OSAS), esthetics and functional problems. To correct the skeletal deformities, the maxilla was anteriorly repositioned by employing LeFort I osteotomy following pre-surgical orthodontic treatment, because a mandibular setback might induce disordered breathing and cause OSAS. After active treatment for 13 months, satisfactory occlusion was achieved and an acceptable facial and oral profile was obtained. In addition, the apnea hypopnea index (AHI) decreased from 18.8 preoperatively to 10.6 postoperatively. Furthermore, after a follow-up period of 7 months, the AHI again significantly decreased from 10.6 to 6.2. In conclusion, surgical advancement of the maxilla using LeFort I osteotomy has proven to be useful in patients with this kind of skeletal malocclusion, while preventing a worsening of the OSAS. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 67 5 2013 Relationship between Orthodontic Expertise and Perception of Need for Orthodontic Treatment for Mandibular Protrusion in Japan 277 283 EN Takashi Murakami Akihito Fujii Yuya Kawabata Hiroaki Takakura Rie Yamaue Tarek Abdulsamad Ali Balam Shingo Kuroda Noriaki Kawanabe Hiroshi Kamioka Takashi Yamashiro Original Article 10.18926/AMO/51863 The aims of this study were to investigate how the Peer Assessment Rating (PAR index) predicts the perceived need for orthodontic treatment of mandibular protrusion in Japanese subjects, and to elucidate whether the perceived need for treatment was affected by the ratersʼ orthodontic expertise. The subjects were 110 dental students and 32 orthodontists. We showed them casts of 10 untreated mandibular protrusion cases and gave them a questionnaire in which they had to describe their perceptions of the orthodontic treatment needs using a 10-point visual analog scale (VAS). The PAR index was used for cast evaluation. The PAR index scores showed significant correlations with the VAS scores. In casts with a low PAR score, there were no differences in the VAS scores between orthodontists and students. In casts with a PAR score greater than 23, the orthodontists perceived a significantly greater treatment need than did the students;for scores of 22, 28, and 29, students who had received orthodontic treatment themselves were more likely to perceive the treatment need. The PAR index is a good clinical predictor for assessing the perceived treatment needs for mandibular protrusion. Perception of the need for orthodontic treatment for mandibular protrusion depended on the degree of orthodontic expertise in Japanese subjects. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 13 2 2008 Primary cultures of chick osteocytes retain functional gap junctions between osteocytes and between osteocytes and osteoblasts 108 117 EN Hiroshi Kamioka Yoshihito Ishihara Hans Ris Sakhr A. Murshid Yasuyo Sugawara Teruko Takano Yamamoto Soo-Siang Lim The inaccessibility of osteocytes due to their embedment in the calcified bone matrix in vivo has precluded direct demonstration that osteocytes use gap junctions as a means of intercellular communication. In this article, we report successfully isolating primary cultures of osteocytes from chick calvaria, and, using anti-connexin 43 immunocytochemistry, demonstrate gap junction distribution to be comparable to that found in vivo. Next, we demonstrate the functionality of the gap junctions by (1) dye coupling studies that showed the spread of microinjected Lucifer Yellow from osteoblast to osteocyte and between adjacent osteocytes and (2) analysis of fluorescence replacement after photobleaching (FRAP), in which photobleaching of cells loaded with a membrane-permeable dye resulted in rapid recovery of fluorescence into the photobleached osteocyte, within 5 min postbleaching. This FRAP effect did not occur when cells were treated with a gap junction blocker (18 alpha-glycyrrhetinic acid), but replacement of fluorescence into the photobleached cell resumed when it was removed. These studies demonstrate that gap junctions are responsible for intercellular communication between adjacent osteocytes and between osteoblasts and osteocytes. This role is consistent with the ability of osteocytes to respond to and transmit signals over long distances while embedded in a calcified matrix. No potential conflict of interest relevant to this article was reported.