Orthognathic Surgery in Patients With Von Willebrand's Disease: A Report of Four Cases and Literature Review.

Von Willebrand's disease (VWD), characterized by quantitatively or qualitatively abnormal von Willebrand factor (VWF), is the most common inherited bleeding disorder. There is limited evidence of treatment using orthognathic surgery in patients with VWD. This report focuses on four patients with VWD who underwent orthognathic surgery and received Factor VIII/VWF concentrates (Confact F) preoperatively. One patient with type 3 (severe) VWD underwent delayed extubation owing to laryngeal edema and exhibited epistaxis thereafter. No perioperative complications were observed in any of the other patients. Two of the four patients were diagnosed with VWD during preoperative screening. Most young adults do not experience general anesthesia and, therefore, may not have undergone blood tests at a hospital. Thus, preoperative screening and adoption of a multidisciplinary approach to orthognathic surgery is important in patients with bleeding disorders such as VWD. Close communication between anesthetists, surgeons, and hematologists is essential to ensure effective management during the perioperative period.

Squamous cell carcinoma of mandibular gingiva producing both parathyroid hormone-related protein and granulocyte colony-stimulating factor: a case report.

We describe a case of mandibular gingival carcinoma with hypercalcaemia and leukocytosis caused by tumour-derived parathyroid hormone-related protein (PTHrP) and granulocyte colony-stimulating factor (G-CSF). A 54-year-old man presented to our Department of Oral and Maxillofacial Surgery with a chief complaint of a left-sided mandibular gingival ulcer. A 42 mm × 20 mm sized ulcer was found on the left lower molar gingiva. Squamous cell carcinoma was pathologically diagnosed. The patient underwent a hemimandibulectomy, left-sided radical neck dissection, plate reconstruction, pectoralis major musculocutaneous flap reconstruction, and tracheostomy under general anaesthesia. Pathologically, two metastatic lymph nodes were identified. Residual tumour was suspected at the resection margins. Eight weeks after surgery, the patient started postoperative concurrent chemoradiotherapy (CCRT). Two weeks after CCRT, the patient developed hypercalcaemia. Serum levels of PTHrP and G-CSF increased in parallel with the progression of hypercalcaemia and leukocytosis. Immunohistochemical analysis of the surgical specimen showed positivity for G-CSF. Based on these clinical and pathological findings, the patient was diagnosed with hypercalcaemia and leukocytosis associated with malignancy and was treated with denosumab. Irradiation was terminated at 50 Gy because CT showed rapid disease progression. Chemotherapy was initiated, however, four weeks after the start of chemotherapy, a CT scan showed increased metastases and pleural dissemination. Therefore, chemotherapy was discontinued. One week after the chemotherapy was discontinued, the patient died of respiratory failure.

A Novel Dressing Method to Achieve Early Natural Tracheostoma Closure.

Tracheotomy is a routine surgical procedure in oral and maxillofacial surgery. After decannulation, spontaneous tracheostoma closure is usually expected. However, wound healing is often delayed, requiring 1 to 2 weeks for healing and resulting in the need for surgical closure. Although many reports have described the surgical closure of a tracheostoma, few reports have focused on the dressing methods for closure of tracheal openings after decannulation. Herein, the authors report a new tracheostoma closure method that does not rely on surgical closure or the adhesive strength of the tape. The authors' conventional dressing method was to place gauze over the tracheostoma after decannulation and apply pressure through elastic tape or with a film dressing to seal the tracheostoma and achieve natural closure by reducing the leakage of air and tracheal secretions. However, the conventional method cannot completely prevent the leakage of air and tracheal secretions. We developed a novel method to achieve early closure by markedly reducing the leakage by partially inserting the gauze into the tracheostoma.

Platelet-Rich Fibrin-Conditioned Medium as an Alternative to Fetal Bovine Serum Promotes Osteogenesis of Human Dental Pulp Stem Cells.

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.

Computed tomography evaluation of risk factors for an undesirable buccal split during sagittal split ramus osteotomy.

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.

VCAM-1 and GFPT-2: Predictive markers of osteoblast differentiation in human dental pulp stem cells.

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.

Novel Cell Therapy Using Mesenchymal Stromal Cell Sheets for Medication-Related Osteonecrosis of the Jaw.

Despite medication-related osteonecrosis of the jaw (MRONJ) being first reported in 2003, the optimal treatment and prevention modalities for MRONJ are not clear. As a result, dentistry, oral surgery, and departments involved in the treatment of cancer and bone diseases are struggling with the management of MRONJ. Several cases of MRONJ cannot be managed by conventional treatment strategies recommended in various position papers. Therefore, studies have been conducted to investigate the efficacy of novel therapies for MRONJ. However, the optimal treatment is unknown. Several cell therapies including autologous cell transplantation have been reported for MRONJ. Although the efficacy of cell therapy for MRONJ has been demonstrated, large, statistically accurate clinical trials are lacking. We have been investigating the efficacy of MRONJ treatment using mesenchymal stromal cell (MSC) sheets since 2013 and confirmed its efficacy through various experiments, wherein MSC sheets were transplanted in model rats and beagle dogs with MRONJ-like lesions. Based on these results, we are planning to conduct a clinical trial of MRONJ therapy using periodontal ligament-derived MSC sheets.

A Case of Orthognathic Surgery for Jaw Deformity in a Patient with Spinocerebellar Ataxia.

Spinocerebellar ataxia (SCA) is a progressive neurodegenerative disease that can cause various ataxia symptoms. Here we report a patient with spinocerebellar ataxia who underwent orthognathic surgery to correct a mandibular protrusion with facial asymmetry. A 33-year-old woman was admitted to our hospital for orthognathic surgery. She started preoperative orthodontic treatment after a diagnosis of mandibular protrusion with facial asymmetry. Two and a half years later, after completing preoperative orthodontic treatment, she returned to our hospital after being diagnosed with spinocerebellar ataxia. After discussing the risk of surgery with the anesthesiologist and neurologist, we elected to perform orthognathic surgery after the patient provided informed consent. Sagittal split ramus osteotomy and intraoral vertical ramus osteotomy were performed under general anesthesia, but no remarkable perioperative complications occurred. After a 3-year follow-up, the occlusion has remained stable, and no postoperative relapse occurred. Whether we should provide surgical treatment for SCA patients is controversial. However, when long-term predictions were considered, altering an occlusion could improve a patient's quality of life in the present case.

Evaluation of Facial Soft Tissue in Patients With Cleft Lip and Palate Corrected Using Maxillary Protraction Appliances.

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.

Effects of Helioxanthin Derivative-Treated Human Dental Pulp Stem Cells on Fracture Healing.

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.

Bone Regeneration Potential of Human Dental Pulp Stem Cells Derived from Elderly Patients and Osteo-Induced by a Helioxanthin Derivative.

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.

Identification of neurospheres generated from human dental pulp stem cells in xeno-/serum-free conditions.

INTRODUCTION: Cell-based therapies require an emerging alternative treatment using easily harvested cell sources. Neural stem cells derived from various tissues, including brain, bone marrow, skin and retina can give rise to both neurons and glial cells. Recently, human dental pulp stem cells (DPSCs) and stem cells from human exfoliated deciduous teeth (SHED) were demonstrated to have mesenchymal stem cell-like abilities such as self-renewal and multi-lineage differentiation, including neuron and glial cells. Moreover, DPSCs and SHED show a higher proliferation rate and a higher number of population doublings compared with adult bone marrow stromal stem cells. Therefore, DPSCs are a useful source that can be applied in cell replacement therapy for various neurological disorders. Generally, the conventional culture methods for DPSCs have used serum, therefore the undefined components in culture medium may complicate investigations of the molecular mechanisms that control the self-renewal and differentiation of DPSCs. However, neural stem cells proliferate to form 'neurospheres' in suspension in vitro in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). No study to date has obtained neurospheres from DPSCs in serum-free conditions in primary culture. Thus, the aim of this study was to establish a method for the proliferation and neural differentiation of DPSCs in xeno- and serum-free conditions in primary culture. METHODS: DPSCs were obtained from the dental pulp of wisdom teeth from healthy individuals (18-41 years old) and cultured in conventional medium containing 15% fetal bovine serum and xeno-/serum-free medium. We evaluated the proliferation of DPSCs, neurosphere generation, and neural differentiation under xeno-/serum-free conditions by flow cytometry, immunohistochemistry, and real-time polymerase chain reaction. RESULTS: In proliferation medium without xeno/serum, DPSCs can proliferate and generate neurospheres, however, the neurospheres had limited self-renewal ability. Under differentiation conditions, class III ß-tubulin (TUBB3) and microtubule-associated protein (MAP2) were more significantly expressed in neurospheres derived from DPSCs in xeno-/serum-free culture conditions than in DPSCs in conventional culture conditions. CONCLUSIONS: Our result demonstrated that neurosphere generation from DPSCs in xeno-/serum-free culture may be an accessible source for clinical cell replacement therapies for neuronal degenerative diseases.

The Usefulness of Saturated Salt Solution Embalming Method for Oral Surgical Skills Training: A New Cadaveric Training Model for Bone Harvesting.

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.

Follicular lymphoid hyperplasia of the posterior maxillary site presenting as uncommon entity: a case report and review of the literature.

BACKGROUND: Follicular lymphoid hyperplasia (FLH) is characterized by an increased number and size of lymphoid follicles. In some cases, the etiology of FLH is unclear. FLH in the oral and maxillofacial region is an uncommon benign entity which may resemble malignant lymphoma clinically and histologically. CASE PRESENTATION: We report the case of a 51-year-old woman who presented with an asymptomatic firm mass in the left posterior maxillary site. Computed tomography scan of her head and neck showed a clear circumscribed solid mass measuring 28 × 23 mm in size. There was no evidence of bone involvement. Incisional biopsy demonstrated benign lymphoid tissue. The patient underwent complete surgical resection. Histologically, the resected specimen showed scattered lymphoid follicles with germinal centers and predominant small lymphocytes in the interfollicular areas. Immunohistochemically, the lymphoid follicles were positive for CD20, CD79a, CD10, CD21, and Bcl6. The germinal centers were negative for Bcl2. Based on these findings, a diagnosis of benign FLH was made. There was no recurrence at 1 year postoperatively. CONCLUSIONS: We diagnosed an extremely rare case of FLH arising from an unusual site and whose onset of entity is unknown. Careful clinical and histopathological evaluations are essential in making a differential diagnosis from a neoplastic lymphoid proliferation with a nodular growth pattern.

A new hydrophilic polysulfone hemodialysis membrane can prevent platelet-neutrophil interactions and successive neutrophil activation.

PURPOSE:: Microaggregates have often been observed during hemodialysis and are clearly associated with complications of hemodialysis therapy. In this study, we aimed to clarify the effects of two polysulfone membranes, with different abilities to activate blood cells, on the formation of these microaggregates; we also investigated their molecular mechanisms. METHODS:: Human whole blood was circulated through a mini-module dialyzer using the membranes in vitro; platelet-neutrophil complexes in blood were determined by flow cytometry. Isolated human neutrophils were incubated with the membranes in plasma, in the presence or absence of platelets, followed by flow cytometric analysis of intracellular reactive oxygen species and cell-surface activated CD11b on neutrophils. RESULTS:: CX-U, a conventional polysulfone membrane with remarkable cell activation, induced the formation of platelet-neutrophil complexes; however, NV-U, a new hydrophilic polysulfone membrane with slight or no cell activation, did not cause complex formation. Moreover, CX-U-induced reactive oxygen species production and the increase in activated CD11b expression on neutrophils were enhanced by platelets. On the other hand, NV-U hardly affected neutrophil activation, regardless of whether platelets were present or not. The enhancement of CX-U-induced neutrophil activations by platelets was greatly inhibited by anti-CD62P antibody. CONCLUSION:: The ability of polysulfone membranes to activate blood cells is closely related to platelet-neutrophil interaction. Therefore, a biocompatible membrane, like NV-U, can be expected to prevent microaggregate formation during hemodialysis and avoid subsequent cell activation.

Biocompatibility of Polysulfone Hemodialysis Membranes and Its Mechanisms: Involvement of Fibrinogen and Its Integrin Receptors in Activation of Platelets and Neutrophils.

Activation of blood cells during hemodialysis is considered to be a significant determinant of biocompatibility of the hemodialysis membrane because it may affect patient health adversely through microvascular inflammation and oxidative stress. This study found very different cell activation among various polysulfone (PSf) hemodialysis membranes. For example, CX-U, a conventional PSf membrane, induced marked adhesion of platelets to its surface and increased surface expression of activated CD11b and production of reactive oxygen species (ROS) by neutrophils; while NV-U, a hydrophilic polymer-immobilized PSf membrane, caused little platelet adhesion and slight CD11b expression and ROS production by neutrophils. Analysis of the molecular mechanisms of the above phenomena on CX-U and NV-U indicated that anti-integrin GPIIb/IIIa antibody blocked platelet adhesion, and that the combination of anti-CD11b (integrin α subunit of Mac-1) and anti-integrin αvß3 antibodies blocked ROS production by neutrophils. Plasma-derived fibrinogen, a major ligand of GPIIb/IIIa, Mac-1, and αvß3 on membranes, was thus analyzed and found to be more adsorbed to CX-U than to NV-U. Moreover, comparison between five PSf membranes showed that the number of adherent platelets and neutrophil ROS production increased with increasing fibrinogen adsorption. These results suggested that fibrinogen, adsorbed on membranes, induced GPIIb/IIIa-mediated platelet activation and Mac-1/αvß3-mediated neutrophil activation, depending on the amount of adsorption. In conclusion, the use of biocompatible membranes like NV-U, which show lower adsorption of fibrinogen, is expected to reduce hemodialysis-induced inflammation and oxidative stress by minimizing cell activation.

Anti-IL-12/IL-23p40 antibody ameliorates dermatitis and skin barrier dysfunction in mice with imiquimod-induced psoriasis-like dermatitis.

Psoriasis is a chronic inflammatory skin disease characterized by erythema, skin hyperplasia, scales, and keratinocyte hyperproliferation. While the cause of psoriasis is not clearly understood, a dysregulated immune system, especially activation of IL-23/IL-17 axis, has been strongly implicated in the pathogenesis of psoriasis. For example, anti-IL-23 therapy is effective in psoriasis patients, and thus IL-23 is considered as a potential therapeutic target for the treatment of psoriasis. The skin barrier provides protection of the human body against infection from external pathogens. Dysfunction of the skin barrier is also one of the characteristics in psoriasis and is correlated with disease severity. However, there have been no reports regarding the effectiveness of antipsoriatic agents on the skin barrier dysfunction of psoriasis. In this study, we examined the effect of anti-IL-12/IL-23p40 monoclonal antibody (p40 mAb) on dermatitis symptoms and skin barrier dysfunction in mice with imiquimod-induced psoriasis-like dermatitis. We found that p40 mAb suppressed epidermal thickness and increased transepidermal water loss (TEWL) as indicator for skin barrier function with accompanying suppression of IL-23p19, IL-17A, IL-22, and keratin 16 gene expression. These results suggest that p40 mAb is not only effective against dermatitis symptoms but also skin barrier dysfunction in mice with imiquimod-induced psoriasis-like dermatitis. This is the first report on the effect of p40 mAb on skin barrier dysfunction related to psoriasis. Taken together, our results indicate the possibility of new insights as well as the therapeutic potential of anti-IL-23 for the treatment of psoriasis.

Simple Technique for Reducing the Buccal Fat Pad During Mandibular Orthognathic Surgery.

Sagittal split ramus osteotomy and intraoral vertical ramus osteotomy are commonly performed for the correction of jaw deformities. However, during mandibular orthognathic surgeries such as sagittal split ramus osteotomy and intraoral vertical ramus osteotomy , the authors sometimes encounter exposure of the buccal fat pad (BFP), which decreases the surgical field. The exposed BFP makes it difficult to perform these operations, may result in unexpected complications, and may increase the operation time. Therefore, the authors herein describe a simple, safe, and convenient technique for reducing the volume of the exposed BFP during mandibular orthognathic surgery using an electric knife in the coagulation mode.

Bone regeneration by human dental pulp stem cells using a helioxanthin derivative and cell-sheet technology.

BACKGROUND: Human dental pulp stem cells (DPSCs), which have the ability to differentiate into multiple lineages, were recently identified. DPSCs can be collected readily from extracted teeth and are now considered to be a type of mesenchymal stem cell with higher clonogenic and proliferative potential than bone marrow stem cells (BMSCs). Meanwhile, the treatment of severe bone defects, such as fractures, cancers, and congenital abnormalities, remains a great challenge, and novel bone regenerative techniques are highly anticipated. Several studies have previously shown that 4-(4-methoxyphenyl)pyrido[40,30:4,5]thieno[2,3-b]pyridine-2-carboxamide (TH), a helioxanthin derivative, induces osteogenic differentiation of preosteoblastic and mesenchymal cells. However, the osteogenic differentiation activities of TH have only been confirmed in some mouse cell lines. Therefore, in this study, toward the clinical use of TH in humans, we analyzed the effect of TH on the osteogenic differentiation of DPSCs, and the in-vivo osteogenesis ability of TH-induced DPSCs, taking advantage of the simple transplantation system using cell-sheet technology. METHODS: DPSCs were obtained from dental pulp of the wisdom teeth of five healthy patients (18-22 years old) and cultured in regular medium and osteogenic medium with or without TH. To evaluate osteogenesis of TH-induced DPSCs in vivo, we transplanted DPSC sheets into mouse calvaria defects. RESULTS: We demonstrated that osteogenic conditions with TH induce the osteogenic differentiation of DPSCs more efficiently than those without TH and those with bone morphogenetic protein-2. However, regular medium with TH did not induce the osteogenic differentiation of DPSCs. TH induced osteogenesis in both DPSCs and BMSCs, although the gene expression pattern in DPSCs differed from that in BMSCs up to 14 days after induction with TH. Furthermore, we succeeded in bone regeneration in vivo using DPSC sheets with TH treatment, without using any scaffolds or growth factors. CONCLUSIONS: Our results demonstrate that TH-induced DPSCs are a useful cell source for bone regenerative medicine, and the transplantation of DPSC sheets treated with TH is a convenient scaffold-free method of bone healing.