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Medication-related osteonecrosis of the jaw (MRONJ) is an intractable form of osteonecrosis of the jaw that rarely occurs in patients using bone resorption inhibitors such as bisphosphonates (BPs). Then, extracellular vesicles (EVs) carry various signaling molecules, such as mRNAs, microRNAs (miRNAs), and proteins, and have attracted attention as intercellular communication tools. Recently, the role of EVs in communication between osteoclasts and surrounding bone cells has been confirmed. This study aimed to elucidate the effects of EVs derived from osteoclasts treated with zoledronic acid (ZA), one of the BPs on osteoclast function. EVs were isolated by ultracentrifugation of the culture supernatant of osteoclasts treated with ZA, and miRNAs were extracted from these EVs. Tartrate-resistant acid phosphatase staining of the ZA treated osteoclasts showed reduced osteoclastogenesis. In addition, pit assay showed that ZA significantly decreased the bone resorption capacity of osteoclasts. miRNA-seq analysis identified 11 upregulated and 5 downregulated differentially expressed genes (DEGs) in the miRNA of EVs derived from ZA-treated osteoclasts compared to EVs derived from osteoclasts not treated with ZA. qRT-PCR analysis confirmed the amount of these specific miRNAs, with miR-146a-5p, and miR-322-3p being significantly upregulated by ZA. Overexpression of miR-146a-5p in osteoclasts inhibited osteoclastogenesis and decreased the mRNA expression of osteoclast markers. In addition, Traf6 was identified as a candidate target gene of miR-146a-5p in several miRNA databases. Indeed, the overexpression of miR-146a-5p decreased the expression level of Traf6 in osteoclasts. Additionally, overexpression of miR-322-3p in the pre-osteoblast, MC3T3-E1 cells, resulted in a significant increase in the mRNA expression levels of Sp7. Our data indicate that BPs attenuate osteoclastogenesis by simultaneously altering the characteristics of osteoclast-derived EVs. Overexpression of miR-146a-5p and miR-322-3p influences osteoclast differentiation, and Traf6 is a target gene of miR-146a-5p. On the other hand, Overexpression of miR-322-3p affects osteoblast differentiation. We suggest that ZA-treated osteoclast-derived EVs may play an important role in osteoclast function and bone resorption., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Dental pulp stem cells (DPSCs) demonstrate high proliferative and multilineage differentiation potential. As previously reported, the helioxanthin derivative 4-(4-methoxyphenyl)pyrido[40,30:4,5]thieno[2,3-b]pyridine-2-carboxamide (TH) has been demonstrated to induce the osteogenic differentiation of DPSCs. However, the mechanism of osteogenesis induced by TH in DPSCs remains unknown. The objective of this study was to identify functional extracellular vesicle (EV) microRNAs (miRNAs), and the principal genes involved in the TH-induced osteogenesis of DPSCs. DPSCs were derived from dental pulp extracted from the third molars of three healthy subjects, and were cultured with or without TH. miRNAs were extracted from DPSC-derived EVs. The gene expression patterns of mRNA and miRNA were compared using RNA-Seq and miRNA-Seq. To investigate miRNA/mRNA interacting networks, functional analyses were performed by Ingenuity Pathway Analysis. Alkaline phosphatase (ALP) staining demonstrated that treatment with TH resulted in enhanced ALP activity in DPSCs after 7 days. The expression levels of ALP and type 1 collagen alpha 1 were significantly higher in TH-induced DPSCs on day 7. RNA-Seq and miRNA-Seq analyses identified 869 differentially expressed genes (DEGs) and 18 miRNA-DEGs. Gene Ontology analysis of the mRNA-Seq results showed that TH induced several biological activities associated with signal transduction, cell adhesion, and cell differentiation. Integrated miRNA-mRNA analyses showed that these miRNAs contain the targeting information of 277 mRNAs of the DEGs. Among them, 17 target genes known to be involved in the differentiation of osteoblasts, and 24 target genes known to be involved in the differentiation of bone cells were identified. Quantitative real-time PCR showed that WNT5a expression in DPSCs was upregulated by 48 h of TH treatment. Upstream regulator analysis indicated that WNT3a , FOS , and RAC1 may be responsible for gene expression changes in DPSCs after TH treatment. EV miRNA regulatory networks might play crucial roles in TH-induced osteogenic differentiation of DPSCs. Our results presented herein offer valuable insights that will facilitate further research into the mechanism of osteogenesis of DPSCs, which is expected to lead to the clinical application of TH-induced DPSCs for bone regeneration. Furthermore, EVs derived from TH-induced DPSCs might be useful as therapeutic tools for bone defects.

Objective: The aim of this Technical note is to present a new assessment method of alveolar bone grafts after secondary alveolar bone grafting using automatic registration and artificial intelligence (AI)-based segmentation., Methods: A total of 7 Japanese patients (4 men and 3 women) with a unilateral cleft lip, alveolus, and/or palate, who underwent secondary alveolar bone grafting between March 2021 and August 2022 were evaluated. Computed tomography (CT) analyses were performed about 1 month before the surgery, and 1 day and 6 months after the surgery. All CT images were imported into a 3-dimensional analysis workstation. CT images from after the surgery were superimposed onto CT images from before the surgery, by automatic rigid image registration. The segmentation of bone tissues was automatically performed by the AI-based function. Grafted bone was extracted by subtraction of the bone tissue after the surgery from the bone tissue before the surgery. The volumes and Hounsfield units (HUs) of the grafted bones were calculated. The intraclass correlation coefficient (ICC) was reviewed to assess inter-rater reliability., Results: The ICCs (2,1) of the volumes and HUs measured by the observers immediately after the surgery were 0.95 and 0.99, respectively. On the other hand, the ICCs (2,1) of the volumes and HUs measured by the observers 6 months after the surgery were 0.81 and 0.57, respectively., Conclusions: Our new assessment method enables simple and quick evaluation of residual grafted bone after secondary alveolar bone grafting and demonstrated relatively high inter-rater reliability., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

Objectives: Immunotherapy with nivolumab for patients with recurrent/metastatic oral squamous cell carcinoma has not been evaluated. Here, we aimed to examine the efficacy, safety, and prognostic factors of nivolumab in these patients., Materials and Methods: This multicenter retrospective observational study involved patients who received nivolumab between April 2017 and June 2019. The patient characteristics were evaluated for association with progression-free and overall survival. Progression-free and overall survival rates were calculated; parameters that were significant in the univariate analysis were used as explanatory variables. Independent factors for progression-free and overall survival were identified using multivariate analysis., Results: Totally, 143 patients were included. The overall response and disease control rates were 27.3% and 46.2%, respectively. The median, 1- and 2-year progression-free survival rates were 2.7 months, 25.4%, and 19.2%, respectively; those for overall survival were 11.2 months, 47.3%, and 33.6%, respectively. The independent factors affecting progression-free survival were performance status and immune-related adverse event occurrence, whereas those affecting overall survival were performance status, target disease, and number of previous lines of systemic cancer therapy. Eight patients reported grade ≥3 immune-related adverse events., Conclusion: Nivolumab was effective for recurrent/metastatic oral squamous cell carcinoma treatment and was well tolerated by patients., (© 2022 Wiley Periodicals LLC.)

Oral cancer is the sixth most common cancer worldwide, with approximately 530,000 new cases and 300,000 deaths each year. The process of carcinogenesis is complex, and survival rates have not changed significantly in recent decades. Early detection of cancer, prognosis prediction, treatment selection, and monitoring of progression are important to improve survival. With the recent significant advances in analytical technology, liquid biopsy has made it possible to achieve these goals. In this review, we report new results from clinical and cancer research applications of liquid biopsy, focusing on extracellular vesicles (EVs) among the major targets of liquid biopsy, namely, circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and EVs. In addition, the potential application of EVs derived from gram-negative bacteria (outer membrane vesicles; OMVs) among oral bacteria, which have recently attracted much attention, to liquid biopsy for oral cancer will also be addressed., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2023. Published by Elsevier Inc.)

Objective: The one-piece dental implant was originally designed to overcome the structural weaknesses of the two-piece implant. However, a fractured one-piece implant requires removal because the abutment cannot be repaired or replaced to support new prosthetic restorations. The aim of this study was to clarify the features and risk factors for fracture of the one-piece implant., Methods: This study was designed as a retrospective case series research. The subjects were patients who were treated for fractures of the one-piece implant at a clinic in Japan between 2012 and 2021. Fractures of the one-piece implant were diagnosed by cone-beam computed tomography, and the association between age and duration from implant placement to fracture was analyzed by one-way ANOVA followed by the Tukey test., Results: Eighteen patients and 20 one-piece implants (under 39 years: 5 patients and 6 implants; 40-59 years: 7 patients and 7 implants; over 60 years: 6 patients and 7 implants) had fractures in their one-piece implants. Of the fractured implants, 11 had a diameter of 3 mm, and 9 had a diameter of 4 mm. The mean durations up to implant fracture were 662 days in the younger group, 1467 days in the middle group, and 1239 days in older group, and the duration was significantly shorter in the younger group. In addition, 83.3% of fracture implants in the younger group were in the molar region. All fractures of the one-piece implants occurred under the bone margin. Two patients had torus mandibularis, and 1 patient was had bruxism., Conclusions: One-piece implants in younger patients that are located in the lower molar position are the most susceptible to implant fracture, and the fracture occurred under the bone margin in all cases., Competing Interests: Conflict of interestNone declared., (© The Association of Oral and Maxillofacial Surgeons of India 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

Human dental pulp stem cells (DPSCs) exhibit multilineage differentiation capabilities and superior clonogenic and proliferative properties. However, the use of animal-derived components such as FBS raises concerns regarding the clinical application of stem-cell-based therapies. Platelet-rich fibrin (PRF) derived from human blood is rich in fibrin, platelets, and growth factors and acts as a bioactive scaffold for grafting with biomaterials. In this study, we assessed the efficacy of PRF-conditioned medium (CM) in promoting DPSCs proliferation and osteogenic differentiation compared with the standard culture medium supplemented with FBS. A comparison of DPSCs cultured in FBS and PRF-CM revealed no differences in characteristics or morphology. However, cells cultured with PRF-CM exhibited inferior proliferation rates and cell numbers during passage in comparison with those cultured with FBS. In contrast, DPSCs cultured in PRF-CM showed significantly higher levels of calcification, and RT-PCR confirmed that the gene expression levels of markers associated with osteoblast differentiation were significantly increased. The PRF-CM approach offers a convenient, straightforward, and advantageous method for culturing DPSCs, without relying on animal-derived components. In summary, this study introduces a novel application of PRF-CM for enhancing the osteogenesis of DPSCs, which provides an alternative to FBS culture medium and addresses concerns associated with the use of animal-derived components in clinical settings.

Surgical site infections (SSI) are associated with increased morbidity and mortality rates. This study aimed to investigate the ability of perioperative oral management (POM) to reduce the risk of SSI in abdominal surgery Real-world data collected from 16 university hospitals in Japan were reviewed. The medical records of consecutive 2782 patients (1750 men and 1032 women) who underwent abdominal surgery under general anesthesia at 16 university hospitals were retrospectively reviewed. Detailed information about SSI was assessed and compared between patients with and without POM in univariate and multivariate analyses. SSI were observed in 275 patients (incidence rate:9.9%), and POM was administered to 778 patients (28.0%). Univariate analyses revealed that diabetes mellitus, Eastern Cooperative Oncology Group performance status, American Society of Anesthesiologists classification, surgical site, preoperative Prognostic Nutritional Index score, POM, extent of surgery, operation time, and intraoperative blood loss were significantly associated with postoperative SSI (Chi-square or Mann-Whitney U test, P < .01). Multivariate analysis revealed that POM had significant preventive effects against postoperative SSI (estimate: -0.245, standard error: 0.080, P < .01). Surgical site, American Society of Anesthesiologists classification, and operation time were also significant and independent clinical predictors of SSI. The analysis of real-world data from 16 university hospitals revealed that, regardless of the content and degree of the problem, the addition of POM has significant beneficial effects in reducing the risk of SSI in patients who undergo abdominal surgery. Medical records from each hospital and data from the Health Care Payment Fund were collected and analyzed retrospectively., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

In the oral and maxillofacial region, the treatment of severe bone defects, caused by fractures, cancers, congenital abnormalities, etc., remains a great challenge. In addition, neurological disorders are frequently accompanied by these bone defects or the treatments for them. Therefore, novel bone regenerative techniques and methods to repair nerve injury are eagerly sought. Among them, strategies using dental pulp stem cells (DPSCs) are promising options. Human DPSCs can be collected easily from extracted teeth and are now considered a type of mesenchymal stem cell with higher clonogenic and proliferative potential. DPSCs have been getting attention as a cell source for bone and nerve regeneration. In this article, we reviewed the latest studies on osteogenic or neural differentiation of DPSCs as well as bone or neural regeneration methods using DPSCs and discussed the potential of DPSCs for bone and nerve tissue regeneration., Competing Interests: The authors declare that they have no competing interests., (Copyright © 2023 Yasuyuki Fujii et al.)

Sagittal split ramus osteotomy (SSRO) sometimes induces an irregular split pattern referred to as a bad split. We investigated the risk factors for bad splits in the buccal plate of the ramus during SSRO. Ramus morphology and bad splits in the buccal plate of the ramus were assessed using preoperative and postoperative computed tomography images. Of the 53 rami analyzed, 45 had a successful split, and 8 had a bad split in the buccal plate. Horizontal images at the height of the mandibular foramen showed that there were significant differences in the ratio of the forward thickness to the backward thickness of the ramus between patients with a successful split and those with a bad split. In addition, the distal region of the cortical bone tended to be thicker and the curve of the lateral region of the cortical bone tended to be smaller in the bad split group than in the good split group. These results indicated that a ramus shape in which the width becomes thinner towards the back frequently induces bad splits in the buccal plate of the ramus during SSRO, and more attention should be paid to patients who have rami of these shapes in future surgeries., Competing Interests: No competing interests exist., (Copyright: © 2023 Fujii et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Introduction: Dental pulp stem cells (DPSCs) have high proliferative and multilineage differentiation potential in mesenchymal stem cells. However, several studies have indicated that there are individual differences in the potential for osteogenic differentiation of DPSCs, and the factors determining these differences are unknown., Objective: To identify the genes responsible for the individual differences in the osteogenic differentiation ability of DPSCs., Methods: We divided DPSCs into high and low osteogenic differentiation ability groups (HG or LG) with ALP and von Kossa stain, and compared the gene expression patterns using RNA-seq. In addition, genes that may affect osteogenic differentiation were knocked down using small interfering RNA (siRNA) and their effects were investigated., Results: The RNA-seq patterns revealed that VCAM1 and GFPT2 were significantly expressed at higher levels in the HG than in the LG. The results of siRNA analysis showed that VCAM1 and GFPT2 knockdown significantly reduced the expression of osteogenic markers. Furthermore, we analyzed the involvement of these two genes in cell signaling in DPSC differentiation. The results indicated that the VCAM1-mediated Ras-MEK-Erk and PI3K/Akt pathways are involved in the osteogenic differentiation of DPSCs, and that GFPT2-mediated HBP signaling influences the osteogenic differentiation of DPSCs., Conclusions: These findings indicate that DPSCs that highly express VCAM1 and GFPT2 have a high capacity for osteogenic differentiation. Evaluation of VCAM1 and GFPT2 expression in undifferentiated DPSCs may predict the outcome of bone regenerative therapy using DPSCs. Moreover, the expression levels of VCAM1 and GFPT2 in DPSCs may be useful in setting criteria for selecting donors for allogeneic cell transplantation for bone regeneration., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Nitric oxide and reactive oxygen species regulate bone remodeling, which occurs via bone formation and resorption by osteoblasts and osteoclasts, respectively. Recently, we found that 8-nitro-cGMP, a second messenger of nitric oxide and reactive oxygen species, promotes osteoclastogenesis. Here, we investigated the formation and function of 8-nitro-cGMP in osteoblasts. Mouse calvarial osteoblasts were found to produce 8-nitro-cGMP, which was augmented by tumor necrosis factor-α (10 ng/ml) and interleukin-1β (1 ng/ml). These cytokines suppressed osteoblastic differentiation in a NO synthase activity-dependent manner. Exogenous 8-nitro-cGMP (30 μmol/L) suppressed expression of osteoblastic phenotypes, including mineralization, in clear contrast to the enhancement of mineralization by osteoblasts induced by 8-bromo-cGMP, a cell membrane-permeable analog of cGMP. It is known that reactive sulfur species denitrates and degrades 8-nitro-cGMP. Mitochondrial cysteinyl-tRNA synthetase plays a crucial role in the endogenous production of RSS. The expression of osteoblastic phenotypes was suppressed by not only exogenous 8-nitro-cGMP but also by silencing of the Cars2 gene, indicating a role of endogenous 8-nitro-cGMP in suppressing the expression of osteoblastic phenotypes. These results suggest that 8-nitro-cGMP is a negative regulator of osteoblastic differentiation., Competing Interests: No potential conflicts of interest were disclosed., (Copyright © 2022 JCBN.)

Background: Despite recent advances in the early detection and treatment of TSCC patients, recurrence rates and survival rates have not improved. The high frequency of lymph node metastasis is one of the causes, and the drug development of new therapeutic mechanisms such as metastasis control is desired. Choline transporter-like protein 1 (CTL1) has attracted attention as a target molecule in cancer therapy. In this study, we examined the antitumor effects of Amb544925, a plant-derived CTL1 inhibitor., Methods: The TSCC cell line HSC-3 was used to measure [ 3 H]choline uptake, cell survival, caspase activity, and cell migration. Xenograft model mice were prepared to verify the antitumor effect of Amb544925., Results: Amb544925 inhibited cell viability and increased caspase-3/7 activity at concentrations that inhibited choline uptake. Amb544925 and ceramide increased SMPD4 expression and suppressed surivivin expression. Furthermore, Amb544925 and ceramide inhibited the migration of HSC-3 cells. In the xenograft model mice, Amb544925 suppressed tumor growth and CTL1 mRNA expression., Conclusions: The plant-derived CTL1 inhibitor Amb544925 is a lead compound of a new anticancer agent exhibiting antitumor effects and inhibition of cell migration through the ceramide/survivin pathway.

The novel coronavirus pandemic has resulted in an urgent need to study the risk of infection from aerosols generated during dental care and to conduct a review of infection controls. However, existing studies on aerosol particles related to dental treatment have mainly evaluated only the scattering range. Few studies have been conducted on the specifics of the generation of aerosol particles in clinical settings, their mechanisms and patterns of distribution throughout open or enclosed spaces, the duration that they remain suspended in air, and the amount and size of particles present. To minimize the influence of background particles, laser lights, a high-sensitivity camera, and particle counters were used in a large super clean laboratory to investigate the dynamics of aerosols generated during the operation of dental micromotors. The results indicate that aerosols tend to scatter upward immediately after generation and then gradually disperse into the surroundings. Most of the particles are less than 5 µm in size (only a few are larger), and all particles are widely distributed over the long term. Our research clearly elucidates that aerosols produced in dental care are distributed over a wide area and remain suspended for a considerable time in dental clinics before settling.

Abstract: Noncontact optical surface scanners have been used to evaluate facial soft tissues. Appropriate evaluation of patients with cleft lip and palate requires comprehensible assessment of the changes in their pre- and post-orthodontic soft tissue and facial growth during chairside assistance. The authors developed a new scanning system that required a shorter measurement time than conventional modalities. The system was implemented on a mannequin and a 6-year-old patient. Seven midfacial landmarks were identified on their faces. The authors measured these landmarks 5 times daily. An experienced orthodontist evaluated and recorded the scores. The scores obtained from the mannequin had a variation of within 0.2 mm, while those obtained from the patient varied within 0.8 mm, except that of the inferior limit of the lips. The study findings suggest that the new laser scanning system can accurately measure facial soft tissue. Further studies should fix patients' head at a definite position for more accurate measurements. An appropriately angled laser sensor would eliminate distortions, thereby increasing the measurement validity., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 by Mutaz B. Habal, MD.)

Abstract: The purpose of the present study was to investigate the efficacy of perioperative oral managements (POMs) on perioperative nutritional conditions in patients undergoing surgery with general anesthesia. Medical records were retrospectively reviewed and the effects of POMs were investigated based on a large number of cases using a multicenter analysis. The profile of serum albumin levels was assessed and compared between patients with and without POMs using the multivariate analysis. Seventeen Eleven thousand and one hundred sixty patients (4,873 males and 6,287 females) were reviewed. Of these, 2710 patients (24.3%) had undergone POMs. The results of a multivariate analysis revealed the significant positive effect of POMs on perioperative serum albumin level (change between at admission and discharge, (Estimate: 0.022, standard error: 0.012, P < .0001). Patient gender, age, surgical site, performance status, the American Society of Anesthesiologists (ASA) physical status classification, operation time, amount of blood loss, and serum albumin level at admission were also significant predictors. Adjusted multivariate analysis of the effects of POMs on perioperative change of serum albumin level in all subjects reveled the significance of POMs intervention (estimate: 0.022, standard error: 0.012, P < .0001). These results suggest that POMs exerts significant positive effects on perioperative serum albumin levels in patients underwent surgery under general anesthesia., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Solitary fibrous tumors (SFTs) are derived from mesenchymal cells originating mainly from the pleura. Reports of bleeding SFTs in head and neck regions are rare. A number of reports have focused on tongue SFT treatments, but to the best of our knowledge, there are no reports on the usefulness of preoperative arterial embolization. Intraoperative and postoperative bleeding can also lead to airway problems. To avoid unnecessary tracheostomy and ligation of the external carotid artery, preoperative vascular embolism should be considered while removing large tumors or tumors with high blood flow. The current report outlines a case of a 32-year-old woman with a tongue solitary fibrous tumor, who underwent right lingual artery embolization with 300-500 and 500-700 µm embosphere microspheres through a vascular catheter the day before surgical resection. The encapsulated tumor was completely excised under general anesthesia with little to no bleeding during the operation., (Copyright: © Hasegawa et al.)

Bone defects affect patients functionally and psychologically and can decrease quality of life. To resolve these problems, a simple and efficient method of bone regeneration is required. Human dental pulp stem cells (DPSCs) have high proliferative ability and multilineage differentiation potential. In our previous study, we reported a highly efficient method to induce osteogenic differentiation using DPSC sheets treated with a helioxanthin derivative (4-(4-methoxyphenyl)pyrido[40,30:4,5]thieno[2,3-b]pyridine-2-carboxamide (TH)) in a mouse calvarial defect model. However, the localization of the DPSCs after transplantation remains unknown. Therefore, in this study, we investigated the localization of transplanted DPSCs in a mouse fracture model. DPSCs were collected from six healthy patients aged 18-29 years, cultured in normal medium (NM), osteogenic medium (OM), or OM with TH, and fabricated them into cell sheets. To evaluate the efficacy of fracture healing using DPSCs treated with OM+TH, and to clarify the localization of the transplanted DPSC sheets in vivo, we transplanted OM+TH-treated DPSC sheets labeled with PKH26 into mouse tibiae fractures. We demonstrated that transplanted OM+TH-treated DPSCs sheets were localized to the fracture site and facilitated bone formation. These results indicated that transplanted OM+TH-treated DPSCs were localized at fracture sites and directly promoted fracture healing.

Human dental pulp stem cells (DPSCs) have high clonogenic and proliferative potential. We previously reported that a helioxanthin derivative (4-(4-methoxyphenyl)pyrido[40,30:4,5]thieno[2-b]pyridine-2-carboxamide (TH)) enhances osteogenic differentiation of DPSCs derived from young patients. However, in the clinical field, elderly patients more frequently require bone regenerative therapy than young patients. In this study, we examined and compared the osteogenic differentiation potential of TH-induced DPSCs from elderly patients and young patients to explore the potential clinical use of DPSCs for elderly patients. DPSCs were obtained from young and elderly patients and cultured in osteogenic medium with or without TH. We assessed the characteristics and osteogenic differentiation by means of specific staining and gene expression analyses. Moreover, DPSC sheets were transplanted into mouse calvarial defects to investigate osteogenesis of TH-induced DPSCs by performing micro-computed tomography (micro-CT). We demonstrated that osteogenic conditions with TH enhance the osteogenic differentiation marker of DPSCs from elderly patients as well as young patients in vitro. In vivo examination showed increased osteogenesis of DPSCs treated with TH from both elderly patients and young patients. Our results suggest that the osteogenic differentiation potential of DPSCs from elderly patients is as high as that of DPSCs from young patients. Moreover, TH-induced DPSCs showed increased osteogenic differentiation potential, and are thus a potentially useful cell source for bone regenerative therapy for elderly patients.

The purpose of this study was to assess the usefulness of saturated salt solution-embalmed cadavers for oral surgical skills training related to bone graft harvesting. Two half-day surgical skills training workshops were held at the Tokyo Medical University utilizing eight cadavers embalmed with the saturated salt solution. A total of 22 participants including oral surgeons, residents, and dentists attended the workshop. Surgical training consisted of six procedures related to intraoral and extraoral bone harvesting. The participants were surveyed to assess self-confidence levels for each surgical procedure before and after completion of each workshop. The Wilcoxon signed-rank test was used to compare the differences between each median score before and after the workshop. There were statistically significant increases in the self-assessed confidence scores in bone harvesting procedures for the zygomatic bone (P = 0.003), maxillary tuberosity (P = 0.002), and other sites (P < 0.001). The anatomical features of saturated salt solution-embalmed cadavers were also examined. The textures of the oral mucosa and skin were similar to those of living individuals. The structure of bone tissues was well-preserved and the hardness was realistic. Consequently, all procedures were performed with sufficient realism. The saturated salt solution method has a relatively low cost of preparation and storage, and almost no odor. The authors suggest that saturated salt solution-embalmed cadavers could provide a new model for oral surgical skills training in bone harvesting., (© 2019 American Association of Anatomists.)

Purpose: Differentiating between bilateral condylar resorption (CR) and mandibular hypoplasia (MH) can be challenging owing to the difficulty in chronological observation and establishing standardized measurements. The purpose of the present study was to assess whether temporomandibular joint (TMJ) function can distinguish between CR and MH and clarify the essential diagnostic imaging tools for CR., Materials and Methods: We performed a cross-sectional study of patients with mandibular retrognathia. The primary predictor variables were a clinical dysfunction score for the TMJ, mandibular plane angle (MPA), SNA angle, SNB angle, and cortical erosion score in the condylar heads. The demographic variables were age, anterior disc displacement, and previous orthodontic treatment. The anatomic variable was the condylar height (CH). The primary outcome variable was the disease status (CR or MH). The patients were divided into the CR group and MH group. The patients with CR were selected on the basis of a CH value of less than 22 mm. TMJ function was assessed using the Helkimo clinical dysfunction index. The CH on panoramic radiographs was measured using the Kjellberg method. The MPA, SNA angle, and SNB angle were analyzed using cephalometric analysis. Cortical erosion in the condylar head was assessed using computed tomography and magnetic resonance imaging., Results: A total of 23 female participants were enrolled in the present study. The average clinical dysfunction score for the TMJ was 4.4 in the CR group and 0.4 in the MH group (P < .05). The average MPA was 41.2° in the CR group and 35.5° in the MH group (P < .05)., Conclusions: The present investigation has shown that assessing TMJ function and analyzing MPA using a cephalometric radiograph can differentiate CR from MH., (Copyright © 2020 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)