Gap junctional intercellular communication attenuates osteoclastogenesis induced by activated osteoblasts.

Osteoblasts participate in both bone formation through the synthesis of extracellular matrix and osteoclast differentiation through the expression of osteoclast differentiation factor. Osteoblasts communicate with each other via gap junctions (GJ), which enable small molecules, such as cAMP, to move to adjacent cells. Therefore, we focused on the role of cAMP propagation between osteoblasts via GJ in the osteoclast-supporting activity of osteoblasts. Osteoclast-supporting activity was evaluated by a co-culture system of osteoblasts with bone marrow-derived mononuclear cells. In this system, ablation of Gja1, a gene encoding connexin 43, in osteoblasts promoted osteoclastogenesis induced by prostaglandin E2 (PGE2). A phosphodiesterase 4 inhibitor increased both osteoclastogenesis and the intracellular cAMP concentration ([cAMP]i) in osteoblasts. Individual cell analysis of [cAMP]i in osteoblasts revealed different responses of each osteoblast to PGE2. Moreover, measurement of real-time [cAMP]i demonstrated cAMP movement from cell to cell via GJ. The inhibition of GJ resulted in the upregulation of [cAMP]i in osteoblasts stimulated by PGE2. This study suggested that GJ intercellular communication exerts protective effects against excess osteoclastogenesis via cAMP movement between osteoblasts.

Comparative Blink Analysis in Patients With Established Facial Paralysis Using High-Speed Video Analysis.

ABSTRACT: This study analyzed the blink characteristics of patients with incomplete and complete facial paralysis. The authors measured and compared the palpebral distance, eyelid movement distance, and the eye-closing ratio of blinks in 55 patients with Bell's palsy or Ramsay Hunt syndrome (Bell & Hunt group) and 14 with complete paralysis (Complete Paralysis group). in the Bell & Hunt group, the palpebral distance (7.94 mm) was smaller on the paralyzed side than on the non-paralyzed side (9.61 mm). The eyeclosing ratio and the upper eyelid movement were reduced on the paralyzed side (65.3% versus 93.7%, 4.61 versus 7.97 mm) and in the Complete Paralysis group (25.3% versus 94.7%, 2.10 versus 8.49 mm). In the Bell & Hunt group, movement of the upper eyelid on the paralyzed side was weakened despite palpebral contracture. The Complete Paralysis group exhibited highly reduced movement in both the upper and lower eyelids.

Inhibitory effects of miRNAs in astrocytes on C6 glioma progression via connexin 43.

In many types of tumor cells, cell communication via gap junction is decreased or missing. Therefore, cancer cells acquire unique cytosolic environments that differ from those of normal cells. This study assessed the differences in microRNA (miRNA) expression between cancer and normal cells. MicroRNA microarray analysis revealed five miRNAs that were highly expressed in normal astrocytes compared with that in C6 gliomas. To determine whether these miRNAs could pass through gap junctions, connexin 43 was expressed in C6 glioma cells and co-cultured with normal astrocytes. The co-culture experiment showed the possibility that miR-152-3p and miR-143-3p propagate from normal astrocytes to C6 glioma in connexin 43-dependent and -independent manners, respectively. Moreover, we established C6 glioma cells that expressed miR-152-3p or miR-143-3p. Although the proliferation of these miRNA-expressing C6 glioma cells did not differ from that of empty vectors introduced in C6 glioma cells, cell migration and invasion were significantly decreased in C6 glioma cells expressing miR-152-3p or miR-143-3p. These results suggest the possibility that miRNA produced by normal cells attenuates tumor progression through connexin 43-dependent and -independent mechanisms.

Effect of gap junction-mediated intercellular communication on TGF-ß induced epithelial-to-mesenchymal transition.

Epithelial-to-mesenchymal transition (EMT) is the process in which epithelial cells lose cell polarity and cell adhesion with surrounding cells to obtain migratory and invasive abilities. On the other hand, the expression of connexin is decreased or lacked in the many types of tumor cells. This study examined the effect of gap junctional intercellular communication (GJIC) on EMT induced by the transforming growth factor-ß1 (TGF-ß1). To investigate the effect of GJIC on EMT in U2OS cells, smooth muscle 22-α (sm22α) promoter-driven luciferase reporter gene was introduced into Cx43-expressing cells (U2OS-Luc Cx43) and into the control parental cell line (U2OS-Luc). TGF-ß1 induced the expression of EMT markers and the sm22α promoter activity of U2OS-Luc cells. Sm22α promoter activity of U2OS cells was neither dependent on the expression of Cx43 nor on the establishment of GJIC among U2OS cells. Furthermore, we found that the homocellular communication among tumor cells did not affected the tumor cell growth and migration. However, we revealed that tumor cell density was an important factor for tumor cells to acquire metastatic phenotype. Interestingly, the co-culture of U2OS cells with osteoblasts revealed that sm22α promoter activity was inhibited only by the GJIC established between these two cell types. These results suggest that normal osteoblast cells negatively regulate the EMT of tumor cells, at least in part. Thus, Cx43-mediated GJIC may have anti-metastatic activity in tumor cells. Our findings provide a new insight into the role of GJIC in cancer progression and metastasis and identify potential therapeutic targets for the treatment of cancer.

Time course analyses of structural changes in the infrapatellar fat pad and synovial membrane during inflammation-induced persistent pain development in rat knee joint.

BACKGROUND: Osteoarthritis (OA) is a common joint disease in aging societies, which is accompanied by chronic inflammation and degeneration of the joint structure. Inflammation of the infrapatellar fat pad (IFP) and synovial membrane (IFP surface) plays essential roles in persistent pain development in patients with OA. To identify the point during the inflammatory process critical for persistent pain development, we performed a time course histological analysis in a rat arthritis model. METHODS: Wistar rats received single intra-articular injection of monoiodoacetic acid (MIA, 0.2 or 1.0 mg/30 µL) in the right knees or phosphate-buffered saline (PBS, 30 µL) as a control in the left knees. Pain avoidance behaviors (weight-bearing asymmetry and tactile hypersensitivity of the plantar surface of the hind paw) were evaluated on days 0, 1, 3, 5, 7, and 14 after injection. Histological assessments of the knee joint were performed on days 0, 1, 3, 5, and 7 after MIA injection. RESULTS: Weight-bearing asymmetry was observed along with the onset of acute inflammation in both the low- (0.2 mg) and high-dose (1.0 mg) groups. In the low-dose group, weight-bearing asymmetry was completely reversed on day 10, indicating that joint pain seemed to alleviate between days 7 and 10. In contrast, we observed persistent joint pain after day 10 in the high-dose group. Histological assessments of the high-dose group indicated that the initial sign of inflammatory responses was observed in the perivascular region inside the IFP. Inflammatory cell infiltration from the perivascular region to the parenchymal region of the IFP was observed on day 3 and reached the IFP surface (synovial membrane) on day 7. Extensive fibrosis throughout the IFP was observed between days 5 and 7 after MIA injection. CONCLUSION: Our data indicated that acute joint pain occurs along with the onset of acute inflammatory process. Irreversible structural changes in the IFP, such as extensive fibrosis, are observed prior to persistent pain development. Thus, we consider that this process may play important roles in persistent pain development.

[Factors associated with behavioral and psychological symptoms in patients with dementia who received home medical treatment: A cross-sectional study (OHCARE study)].

AIM: The present study investigated the behavioral and psychological symptoms of dementia (BPSD) and pharmacological therapy among elderly people with dementia who received home medical treatment. METHODS: This study was part of the Osaka Home Care Registry study (OHCARE-study). Participants were >65 years old with dementia. Demographic and medical data, BPSD, and the LTCI [long-term care insurance] care-need level were collected. A multiple logistic regression analysis was performed in order to clarify the factors associated with BPSD. RESULTS: Among 110 subjects (82.0±11.3 years old), 64.6% had a diagnosis of dementia, most commonly Alzheimer's dementia. Aside from home medical treatment, 58.1% had a nurse visit, 48.1% received home care, and 40.0% used a day service. The prevalence of BPSD was 53.0%. Those with BPSD most frequently had an LTCI care-need level of 3, and the prevalence of BPSD declined as the level increased after 3. Psychotropic drugs were prescribed in 61.5% of those with BPSD. Antipsychotic drugs were used significantly more frequently in those with nursing care resistance, assault and delusions than in others (all, p <0.005). A multivariate analysis showed that the positive predictor of BPSD was antipsychotic drug use, while negative predictors were an LTCI care-need level and the use of visiting rehabilitation. CONCLUSION: The BPSD in elderly dementia patients receiving home medical treatment were clarified. The LTCI care-need level is an independent predictor of BPSD after adjusting for the activities of daily life. Further longitudinal investigations including the BPSD severity and frequency are needed.

Role of cAMP in phenotypic changes of osteoblasts.

Bone remodeling is precisely controlled by bone formation and bone resorption, and osteoblasts are responsible for both processes. Osteoblasts exhibit an osteoclastogenic phenotype in response to elevated intracellular cyclic AMP [cAMP]i levels. However, the role of cAMP in osteoblasts acquiring an osteogenic phenotype is controversial. To elucidate the effect of cAMP on both phenotypes, an osteoblast-like cell line, TMS-12, was established in our laboratory and used in this study. Dibutyryl-cAMP (dBcAMP), a cAMP analogue, inhibited mineralization in TMS-12 cells and MC3T3E1 cells (an osteoblast-like cell line) but promoted osteoclast-supporting activity in TMS-12 cells. Moreover, mineralization was inhibited in glucagon receptor-transduced TMS-12 cells (TMS-12GCGR) after glucagon treatment to increase endogenous [cAMP]i levels. However, the osteoclast-supporting activity of TMS-12GCGR cells was stimulated by glucagon treatment. These cAMP-induced phenotypic changes of osteoblasts were also supported by their gene expression profile. These results suggest that [cAMP]i is an important factor mediating phenotypic changes of osteoblasts. Our findings may provide valuable insights into the mechanisms that underlie bone remodeling in both, healthy and diseased states.

Persistent synovial inflammation plays important roles in persistent pain development in the rat knee before cartilage degradation reaches the subchondral bone.

BACKGROUND: The major complaint of knee osteoarthritis (OA) is persistent pain. Unlike acute inflammatory pain, persistent pain is usually difficult to manage since its pathology is not fully understood. To elucidate the underlying mechanisms of persistent pain, we established 2 different inflammation-induced arthritis models by injecting monoiodo-acetic acid (MIA) into the joint cavity and performed integrated analyses of the structural changes in the synovial tissue and articular cartilage, sensory neuron rearrangement, and pain avoidance behavior in a rat arthritis model. METHODS: Male Wistar rats received intra-articular injections of MIA (0.2 mg/30 µL, low-dose group; 1 mg/30 µL, high-dose group) in the right knee and phosphate buffered saline (PBS; 30 µL, control group) in the left knee. Fluorogold (FG), a retrograde neural tracer, was used to label the nerve fibers for the identification of sensory neurons that dominate the joints in the dorsal root ganglion (DRG). Both knees were subjected to the intra-articular injection of 2% FG in PBS (5 µL) under anesthesia 5-7 days prior to sacrifice. We performed pain avoidance behavior tests (incapacitance and von Frey tests) at 0, 1, 3, 5, 7, 14, 21, and 28 days. At 5, 14, and 28 days, the rats were sacrificed and the knee joint and DRG were excised for histological assessment. The knee joints were stained with hematoxylin and eosin, safranin O, and calcitonin gene-related peptide (CGRP). The DRG were immunostained with CGRP. RESULTS: A transient inflammatory response followed by mild articular cartilage degeneration was observed in the low-dose MIA model versus persistent inflammation with structural changes in the synovial tissue (fibrosis) in the high-dose model. In the high-dose model, full-thickness cartilage degeneration was observed within 2 weeks post-MIA injection. The pain avoidance behavior tests indicated that persistent synovial inflammation and structural changes of the infrapatellar fat pad may play important roles in persistent knee joint pain before the articular cartilage degeneration reaches the subchondral bone. CONCLUSIONS: Transient inflammation without structural changes of the synovial tissues did not induce persistent pain in the rat knee joint before degradation of the articular cartilage reached the subchondral bone plate.

Involvement of CX3CL1 in the Migration of Osteoclast Precursors Across Osteoblast Layer Stimulated by Interleukin-1ß.

The trigger for bone remodeling is bone resorption by osteoclasts. Osteoclast differentiation only occurs on the old bone, which needs to be repaired under physiological conditions. However, uncontrolled bone resorption is often observed in pro-inflammatory bone diseases, such as rheumatoid arthritis. Mature osteoclasts are multinuclear cells that differentiate from monocyte/macrophage lineage cells by cell fusion. Although Osteoclast precursors should migrate across osteoblast layer to reach bone matrix before maturation, the underlying mechanisms have not yet been elucidated in detail. We herein found that osteoclast precursors utilize two routes to migrate across osteoblast layer by confocal- and electro-microscopic observations. The osteoclast supporting activity of osteoblasts inversely correlated with osteoblast density and was positively related to the number of osteoclast precursors under the osteoblast layer. Osteoclast differentiation was induced by IL-1ß, but not by PGE2 in high-density osteoblasts. Osteoblasts and osteoclast precursors expressed CX3CL1 and CX3CR1, respectively, and the expression of CX3CL1 increased in response to interleukin-1ß. An anti-CX3CL1-neutralizing antibody inhibited the migration of osteoclast precursors and osteoclast differentiation. These results strongly suggest the involvement of CX3CL1 in the migration of osteoclast precursors and osteoclastogenesis, and will contribute to the development of new therapies for bone diseases. J. Cell. Physiol. 232: 1739-1745, 2017. © 2016 Wiley Periodicals, Inc.

Involvement of the G-protein-coupled receptor 4 in RANKL expression by osteoblasts in an acidic environment.

Osteoclast activity is enhanced in acidic environments following systemic or local inflammation. However, the regulatory mechanism of receptor activator of NF-κB ligand (RANKL) expression in osteoblasts under acidic conditions is not fully understood. In the present paper, we detected the mRNA expression of the G-protein-coupled receptor (GPR) proton sensors GPR4 and GPR65 (T-cell death-associated gene 8, TDAG8), in osteoblasts. RANKL expression and the cyclic AMP (cAMP) level in osteoblasts were up-regulated under acidic culture conditions. Acidosis-induced up-regulation of RANKL was abolished by the protein kinase A inhibitor H89. To clarify the role of GPR4 in RANKL expression, GPR4 gain and loss of function experiments were performed. Gene knockdown and forced expression of GPR4 caused reduction and induction of RANKL expression, respectively. These results suggested that, at least in part, RANKL expression by osteoblasts in an acidic environment was mediated by cAMP/PKA signaling resulting from GPR4 activation. A comprehensive microarray analysis of gene expression of osteoblasts revealed that, under acidic conditions, the phenotype of osteoblasts was that of an osteoclast supporting cell rather than that of a mineralizing cell. These findings will contribute to a molecular understanding of bone disruption in an acidic environment.

Volumetric changes in transplanted vascularized fat flaps after ischemic or congestive stresses and their relationship to capillary density in a zucker fatty rat model.

BACKGROUND: The aim of this study was to examine volumetric changes in fat flaps after stresses as well as their relationship with capillary density (CD) in a Zucker fatty rat model. METHODS: A total of 12 male Zucker-fa/fa rats were randomly divided into two stress groups. Superficial epigastric fat flaps were evaluated on the right side as control and on the left side as the stress (ischemic or congestive) condition in the same rat in order to avoid biases. Stress conditions were made by obstructing the pedicle vessels with a vascular clip for 3 hours. The volumes of these flaps were measured weekly. After 12 weeks of measurements, the CD of harvested flaps was examined in histologically immunostained sections. Percent changes in the body-weight-corrected flap volume [cFV(%)], the stress/control ratio [FV-ratio(%)], and the stress/control ratio of CD (CD-ratio) were defined. RESULTS: cFV(%) 12 weeks after surgery was 34.7 ± 26.7 in the control flaps and 13.2 ± 10.5 in the stress flaps. The FV-ratio(%) after 12 weeks was 7.4-202.5 (70.2 ± 77.9) in the ischemic group and 14.6-66.3 (37.7 ± 22.2) in the congestive group. The difference in variance between two groups was significant (P = 0.030). cFV(%) correlated with total CD (P = 0.011). The FV-ratio(%) correlated with the CD-ratio (P = 0.002). CONCLUSIONS: Weekly measurements of flap volumes in the Zucker fatty rat model were new and useful methods. The FV-ratio(%) in the congestive group decreased at a constant rate, while that in the ischemic group decreased or increased slightly. The rate of decreases in the flap volume correlated with CD.

[Development of a pre-dehydration assessment sheet: Research among elderly individuals who regularly visited an elderly-care institution].

AIM: In the present study, we defined the state of pre-dehydration (PD) as the suspected loss of body fluids, not accompanied by subjective symptoms, where the serum osmotic pressure ranges from 292 to 300 mOsm/kg・H2O. The goal of this study was to develop a PD assessment sheet based on the results of sensitivity and specificity testing among elderly individuals. METHODS: We evaluated the serum osmotic pressure in 70 subjects >65 years of age who regularly visited an elderly-care institution. We then determined the associations between the serum osmotic pressure and various dehydration-related diagnostic factors identified in our previous study. Risk factors for dehydration were evaluated using a logistic regression analysis and allotted points according to the odds ratio. RESULTS: PD was confirmed in 15 subjects (21.4%) using measurements of the serum osmotic pressure. We developed a PD assessment sheet that consisted of six items: (1) Female gender (4 points), (2) BMI≥25 kg/m2 (5 points), (3) Diuretics (6 points), (4) Laxatives (2 points), (5) Dry skin (2 points) and (6) A desire to consume cold drinks or foods (2 points). The cutoff value at which the risk of PD was high was set at 9 points (total of 21 points) (sensitivity 0.73, specificity 0.82; P<0.001). CONCLUSIONS: In this study, we found that 21.4% of the elderly subjects had PD. Using these data, we developed an effective noninvasive tool for detecting PD among elderly individuals.

Effects of xenon irradiation of the stellate ganglion region on fibromyalgia.

[Purpose] The aim of the study was to determine the effect of xenon irradiation of the stellate ganglion region on fibromyalgia. [Subjects] The study included 5 men and 22 women (age, 56.4 ± 16.3 years [range, 25-84 years]) who were diagnosed with fibromyalgia according to the modified 2010 criteria of the American College of Rheumatology between July and August 2013. [Methods] Bilateral xenon light irradiation (0.38-1.1 µm) around the stellate ganglion was performed in the supine position by physical therapists using a xenon phototherapy device. We evaluated pain before and after irradiation using the visual analogue scale. [Results] We did not observe a relationship between the change in the visual analogue scale score and duration of fibromyalgia. However, we observed a relationship between the change in the visual analogue scale score and the score for the Japanese version of the Fibromyalgia Impact Questionnaire using the Cochran-Armitage test for trend. [Conclusion] Xenon light irradiation of the stellate ganglion significantly decreased the visual analogue scale score in patients with fibromyalgia having a higher score in the Fibromyalgia Impact Questionnaire, suggesting that a stronger effect could be obtained in patients with more severe fibromyalgia.

Vascular plant one-zinc-finger protein 1/2 transcription factors regulate abiotic and biotic stress responses in Arabidopsis.

Plants adapt to abiotic and biotic stresses by activating abscisic acid-mediated (ABA) abiotic stress-responsive and salicylic acid-(SA) or jasmonic acid-mediated (JA) biotic stress-responsive pathways, respectively. Although the abiotic stress-responsive pathway interacts antagonistically with the biotic stress-responsive pathways, the mechanisms that regulate these pathways remain largely unknown. In this study, we provide insight into the function of vascular plant one-zinc-finger proteins (VOZs) that modulate various stress responses in Arabidopsis. The expression of many stress-responsive genes was changed in the voz1voz2 double mutant under normal growth conditions. Consistent with altered stress-responsive gene expression, freezing- and drought-stress tolerances were increased in the voz1voz2 double mutant. In contrast, resistance to a fungal pathogen, Colletotrichum higginsianum, and to a bacterial pathogen, Pseudomonas syringae, was severely impaired. Thus, impairing VOZ function simultaneously conferred increased abiotic tolerance and biotic stress susceptibility. In a chilling stress condition, both the VOZ1 and VOZ2 mRNA expression levels and the VOZ2 protein level gradually decreased. VOZ2 degradation during cold exposure was completely inhibited by the addition of the 26S proteasome inhibitor, MG132, a finding that suggested that VOZ2 degradation is dependent on the ubiquitin/26S proteasome system. In voz1voz2, ABA-inducible transcription factor CBF4 expression was enhanced significantly even under normal growth conditions, despite an unchanged endogenous ABA content. A finding that suggested that VOZs negatively affect CBF4 expression in an ABA-independent manner. These results suggest that VOZs function as both negative and positive regulators of the abiotic and biotic stress-responsive pathways, and control Arabidopsis adaptation to various stress conditions.

Role of intercellular adhesion molecule-2 in osteoclastogenesis.

Osteoclasts, multinucleated bone-resorbing cells, are specialized cells derived from the monocyte/macrophage lineage. Therefore, it is essential for mononuclear precursors to find a fusion partner during its differentiation. Our previous study showed an important role of cell communication via Mac-1 (CD11b/CD18) during osteoclastogenesis. However, the counter receptor of Mac-1 was still unknown. Flow cytometric analysis showed that bone marrow-derived mononuclear cells, used as osteoclast precursors, expressed intercellular adhesion molecule-1 and -2. Quantitative RT-PCR analysis revealed that expression level of ICAM-2 was higher than that of ICAM-1 in bone marrow cells. The osteoclastogenesis induced by receptor activator of NF-kappaB ligand (RANKL) was inhibited by anti-ICAM-2 neutralizing antibody but not by anti-ICAM-1 neutralizing antibody. The inhibitory effect of anti-ICAM-2 antibody on osteoclastogenesis was enhanced by simultaneous treatment of anti-CD11b neutralizing antibody. Furthermore, osteoclastogenesis induced by tumor necrosis factor α (TNFα) was also inhibited by anti-ICAM-2 neutralizing antibody. The involvement of lymphocytes in osteoclastogenesis was excluded, because anti-ICAM-2 antibody inhibited osteoclastogenesis using bone marrow-derived cells from immunodeficiency mice. Immunocytochemical staining demonstrated colocalization of ICAM-2 and Mac-1 during osteoclastogenesis; however, Mac-1 immunoreactivity was lost in differentiated multinucleated osteoclast. These results suggest the important role of ICAM-2/Mac-1 binding in osteoclastogenesis induced by either RANKL or TNFα.

[The need for health consultation services and related factors among non-users of health consultation services residing in urban public apartment complexes].

OBJECTIVES: The aim of this study was to identify the factors associated with the need for health consultation services among non-users of such services within residents of urban public apartment complexes. METHODS: In December 2011, a cross-sectional mail survey was conducted with the inclusion of 2,000 elderly residents, randomly selected from a total of 6,000 residents. We asked about the need for health consultation services, demographic data, daily living situation, medical and care-giving experiences, and health concerns and desires. Data were analyzed using ordinal logistic regression analyses. RESULTS: A total of 534 questionnaires were analyzed from the 553 respondents (response rate 27.7%). Respondents expressed need for health consultation services: very important 21.5%; important 38.2%; unknown 19.1%; not so much important 14.0%; unimportant 6.9%. The analyses revealed that people with greater need tended to have the following features compared to those with less need: lack of independence in daily activities (P=.03), experiencing stress in family relationships (P=.003), having nurses to consult about health concerns (P=.04), do not necessarily need doctor's consultation regarding their health problems (P<.001), feel it difficult to consult doctors when they have health-related questions (P=.007), know about locally-available health consultation services (P=.02). They also wanted to use services they can visit accompanied by acquaintances (P=.002), with one-on-one health consultation regarding their problems (P=.003), where service is free (P=.008), where they receive advice about their illnesses (P<.001) and about their medical and caregiving cost (P=.008), and maintain contact with others using the services (P<.001). CONCLUSION: Although the response rate was low, most of residents expressed a need for a health consultation service. Based on the results of this study, a health consultation service provided by nurses may be an effective solution. They also desire the services to be accessible in the company of their acquaintances, provided one-on-one, free of charge, and to provide opportunities not only for consultation concerning their illnesses but also for interaction with others.

Perceived stress and career planning awareness of Japanese and Taiwanese undergraduate dental hygiene students.

Background/purpose: Dental hygiene students' stress might be rising with increasing undergraduate study content and expansions in dental hygienists' roles and expectations as society changes. This study explored Japanese and Taiwanese dental hygiene students' perceptions of stress and their idea of career planning. Materials and methods: Participants were second- to fourth-year students in the 2020 academic year at Tokyo Medical and Dental University (TMDU; n = 60) and Taipei Medical University (TMU; n = 62). An anonymous questionnaire was distributed, which included questions on demographic information and career planning, as well as the Perceived Stress Scale-10 (PSS-10) and modified Dental Environment Stress questionnaire (DES). Results: The response rates were 100.0% (TMDU) and 96.8% (TMU). The number of participants who chose dental hygiene as the first program choice (P < 0.001) and wished to work as dental hygienists after graduation (P = 0.018) in TMDU was significantly higher than in TMU. There was no significant difference between the two schools' stress levels in both PSS-10 and DES-26. The factors influencing students who wished to work as dental hygienists after graduation were "clinical year or not" (P = 0.007) in TMDU, and the DES factor included items related to lack of confidence in becoming a successful and competent dental hygienist, expectations, and fear of the future (P = 0.033) in TMU. Conclusion: Both schools' students experienced moderate or relatively low levels of stress. TMDU students had higher stress related to academic studies, while TMU students had slightly higher stress related to future anxiety.

Prevalence of Possible Dementia in Patients with Maxillofacial Defects and Difficulty of Inserting Obturator in Maxillectomy Patients: Toward Better Provision of Supportive Care.

As society ages, it is important to understand the prevalence of dementia and the difficulties of inserting prostheses in patients with maxillofacial defects in order to clarify issues in supportive care. We screened 183 patients for dementia using the revised Hasegawa's dementia scale (HDS-R) at the Clinic for Maxillofacial prosthetics, Tokyo Medical and Dental University, and investigated age and sex differences in HDS-R score. We asked 47 of the 183 participants about the difficulty of inserting a maxillofacial obturator prosthesis and collected subjective comments, information about the prosthesis, and data from five assessments. Multiple regression analysis was used to reveal factors associated with insertion difficulty. Overall, 8.7% of the participants were judged to have possible dementia. Men were more likely than women to have possible dementia, and the risk increased with age. Of the 47 participants, 26 reported difficulty inserting their prosthesis, 12 of whom attributed it to their oral defect. Fourteen patients advised following doctor's instructions to practice insertion in order to become accustomed to it. A lower HDS-R score had a significant impact on insertion difficulty. Cognitive function and difficulty inserting maxillary obturator prostheses should be considered in the provision of continuous supportive care to patients with maxillary defects.

Three-dimensional evaluation of the dental arch in cleft lip and palate after prosthetic treatment.

PURPOSE: This study aimed to evaluate the stability of the surface of the maxillary teeth and mucosa in cleft lip and palate (CLP) patients with a maxilla defect or tissue deficiency according to the duration of observation and cleft type. METHODS: Pairs of maxillary casts taken from 18 patients at different time points after prosthodontic treatment were investigated in this study. All 36 casts were scanned with an intraoral scanner, and the acquired images were saved in standard tesselation language (STL) files. The two STL files for each patient were then superimposed using three-dimensional (3D) evaluation software, with 3D deviations shown as a color map. Areas with a 3D deviation within ±0.100 mm were defined as stable. The influence of cleft type and duration of observation on the ratio of stable areas to the entire maxillary surface comprising the teeth and mucosa was investigated using multiple regression analysis. Statistical significance was set at p <0.05. RESULTS: Multiple regression analysis showed that the duration of observation was significantly associated with the stable area ratio (B = -23.463, P<.001), whereas cleft type was not (ß = 0.13, P = 0.301). CONCLUSIONS: The maxillary teeth and mucosa of CLP patients changed over time, with stable areas showing a negative correlation with the observation period. However, the stability of the dental arch was not significantly affected by the cleft type. 3D analysis of the casts of CLP patients allowed for measurements and to accurately assess relapse of the maxillary arch after prosthetic treatment.

Fostering globally competent dental students through virtual team-working, problem-solving and person-centred multi-disciplinary care planning.

Background/purpose: : Development and acquisition of communication, logical thinking, team-building, critical appraisal, critical thinking and person-centred multi-disciplinary care planning must be considered as skill sets and global core competencies for a dental professional. Therefore, an international online study course to foster undergraduate dental students' skill sets in these areas was established and this study aimed to report the perceptions of participants. Materials and methods: An international online course consisting of three levels pertaining to the school year was delivered to dental undergraduates of Japan and Thailand from September to December in 2021. An online questionnaire survey was conducted to obtain feedback from the participants and assess the implementation of the course. Results: In total, 64 responses were obtained from students who participated in all the assigned online sessions and completed the questionnaire (a response rate of 88%). More than 95% of students from each level felt that the programme increased their motivation to study clinical dentistry, and was beneficial for their future and made them appreciate the importance of participating in international exchange. The ratio of favourable respondents was more than 90% with a 95% confidence interval. Conclusion: Fostering globally competent dental students is important and the acquisition of necessary skill sets could be enhanced through international virtual team-working, problem-solving and person-centred multi-disciplinary care planning activities. These are beneficial for undergraduate dental student training so that they graduate with a broader global perspective and an appreciation of the importance of delivering person-centred culturally sensitive dental care.