For a reconstructive surgeon in oral and maxillofacial surgery, repair of massive bone defects in craniofacial region and mandible caused by different types of trauma, extensive bone destruction by cancer or metabolic diseases is amongst one of the most difficult tasks to handle. The aim of this study was to assess the effectiveness and potential effect of incorporating Strontium (Sr) with locally delivered epidermal growth factor (EGF) on osteoclastogenesis and osteoblastogenesis gene expressions of dental stem cells (DSCs) in an in vitro study. Sr, EGF, and dental stem cells (DSCs) with all materials (reagents and drugs) were commercially purchased from companies. Viability test (cytotoxicity test) was carried out to determine compatibility and optimal concentrations of Sr scaffold and EGF in accordance with the protocol of the current study. DSCs were treated with three modalities of drugs base time points, control-0 concentration, DSCs treated with Sr only, DSCs treated with EGF only DSCs treated with Sr/ EGF. RNA from DSCs were extracted from all treated groups. RT-PCR was used to amplify the specific osteoblast/ osteoclast genes markers. Electrophoresis of the RT-PCR products was followed by gel image capturing. Significant enhanced osteoblast markers responsible for bone healing were observed in the DSCs group that were treated with Sr/ EGF as compared with the other studied group. This strategy seems to be a reliable new tool for bone tissue engineering by mean using bone graft material potentiates inducing high capacity of bone wound healing and could be effective strategy in reconstructive surgery when used in in vivo study used stem cellsbased therapy.

Macrophage migration inhibitory factor (MIF) has emerged as an essential proinflammatory cytokine in inflammatory and immune responses. We investigated the expression of MIF in human dental pulp tissue and the function of MIF in human dental pulp fibroblast-like cells. MIF was expressed in areas of dental pulp characterized by a robust inflammatory response, for instance, in human dental pulp tissues that exhibited pathological signs of purulent inflammation. MIF stimulated the expression of prostaglandin-endoperoxide synthase 2 (PTGS2) mRNA and prostaglandin E₂ production in human dental pulp fibroblast-like cells. These effects of MIF on the expression of PTGS2 mRNA and prostaglandin E₂ production were attenuated in the presence of the CXCR2 and CXCR4 antagonists SCH527123 and WZ811. These results suggest that MIF is involved in inflammation by activating CXCR2 and CXCR4 in human dental pulp.

Diabetes mellitus (DM) is a common disease occurring worldwide. Patients with DM are at an increased risk of losing their teeth compared to other individuals. DM increases the risk and severity of chronic inflammatory periodontal diseases, in which, bone resorption is found to occur. Chronic inflammation contributes to the development of DM and DM-associated complications. Hyperglycemia is a hallmark of DM and may contribute to sustained inflammation by increasing the levels of proinflammatory cytokines. However, the mechanisms by which bone-related complications develop in DM after stimulation by the Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS) remain unknown. Results of studies performed to understand the effect of high glucose concentrations on the functions of osteoblasts are contradictory because some have suggested a subsequent increase (although others have suggested a decrease) in the rate of the biomineralization process. Therefore, we evaluated the effect of high glucose levels on the biomineralization and inflammation markers in a human osteoblastic cell line, after stimulation with LPS from P. gingivalis. We treated cells with glucose at concentrations 5.5, 8.0, 12 and 24 mM after stimulation with P. gingivalis LPS (1.0 mg/ml) and determined its effects on cell proliferation, alkaline phosphatase (ALP) activity, osteocalcin (OCN) production, calcium deposition, inflammatory cytokines, and osteogenic cytokines. Results demonstrated that high concentrations of glucose increased cell proliferation, but the ALP activity decreased at concentrations of 12 and 24 mM. Additionally, OCN production and Calcium (Ca) deposition decreased at 24 mM. The levels of inflammatory cytokines (IL-1β, IL-6 and IL-8) decreased at 8.0 and 12 mM. However, the amounts of Runx2 increased significantly in the presence of 12 mM glucose, but decreased beyond this concentration. High glucose concentration decreased hard tissue formation after stimulation by P. gingivalis LPS. Understanding the effect of glucose on osteoblast differentiation and calcium deposition might provide a better understanding of the development and prevention of periodontitis associated with diabetes.

In this study on muscle characteristics and jawbone morphology, the relationship between masticatory muscle properties and jaw deformity was analysed in skeletal Class III patients with asymmetry. The subjects were 27 patients (21 women and 6 men) who had skeletal mandibular prognathism with mandibular asymmetry. The subjects’ ages ranged from 16 to 51 years, with an average of 23.5 years. Patients with lateral displacement of Me 3 mm or more and an ANB angle of 0 ° or less were included. Morphometric measurements were taken from CT images. Biopsy material was collected during surgery for immunohistological typing of muscle fibres, MyHC1, 2a, and 2x isoforms; measurement of MYH1, 2, 7, 8 mRNA expression. In CT morphometry, there was no difference in muscle thickness or cross-sectional area between the deviated and non-deviated sides, but both sides tended to have thinner muscles than the control group. In the typing of muscle fibres by immunohistochemical staining, type 2 fibres were found to be significantly more numerous on the deviated side than on the non-deviated side. Regarding protein quantities, MyHC1 was more abundant on the deviated side than on the non-deviated side. Regarding the expression of mRNA, MYH7 (type 1) and MYH1 (type 2x) showed no difference between the two sides, and MYH2 (type 2a) had a higher expression level on the deviated side than in the control group. The data suggested a tendency for Class III patients to have characteristics of a short face on the deviated side, and a long face on the non-deviated side. It seems that muscle type switching may be in progress.

We investigated the feasibility of estimating the living age of Japanese individuals and distinguishing sex on the basis of results from stable isotope analysis of stable carbon (¹³C) and nitrogen (¹⁵N) isotopes in radicular dentin. In this study, collagen fibers were extracted from the radicular dentin of mandibular second molars in Japanese individuals born between 1891 and 1964, and the carbon and nitrogen isotope ratios (δ¹³C and δ¹⁵N values, respectively) were calculated. The results showed that regression formulae for δ¹³C and δ¹⁵N values were highly reliable for estimating the living age of Japanese individuals, but no sex difference was evident. Use of radicular dentin thus has potential as a technique for estimating the living age of Japanese individuals, whose diet has changed greatly over the years.

Hyperlipidemia inhibits bone formation, which has an adverse impact on the success of dental implants. Fzd9 has been reported to be a positive regulator of osteogenesis. However, the role of Fzd9 in dental implants in hyperlipidemic conditions is still unknown. In current study, we investigated how Fzd9 impacts on implant osseointegration in hyperlipidemic conditions. Models of high-fat medium-stimulated rat bone marrow stromal stem cells (BMSCs) were established. Alkaline phosphatase (ALP), alizarin red S (ARS) and oil red O (ORO) staining were used to examine the osteogenic differentiation of BMSCs. Wistar rats were fed with high-fat diet to induced hyperlipidemia. Titanium implants were implanted into the proximal metaphysis of the bilateral femurs of rats after 8 weeks. Thereafter, 1 mm of bone around each implant was obtained. Implant osseointegration and micromorphology were analyzed with microcomputer tomography (micro-CT) and hematoxylin-eosin (HE) staining. The relative expression levels of Fzd9 and Runx2 were analyzed by quantitative real-time PCR in vitro and in vivo. Western blotting was used to analyzed the protein level of Fzd9. The expression levels of Fzd9 and Runx2 were decreased. Osteogenic differentiation of BMSCs were suppressed under high-fat medium. Less bone formation was observed in hyperlipidemic rats compared to the normal. Hyperlipidemic rats had lower osteoblasts and bone-implant combination (BIC), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N) but higher trabecular spacing (Tb.S), trabecular bone pattern factor (TBf) and osteoclasts. In conclusion, the lower expression of Fzd9 impairs osseointegration in hyperlipidemic conditions via Wnt signaling pathway-related Runx2. Fzd9 may serve as a promising strategy for hyperlipidemia osseointegration.

Previously we have discovered that titanium (Ti) binds with bone phosphoproteins SIBLING protein family, by using a Ti beads chromatography. Furthermore, we showed that the isolated bone phosphoproteins remarkably enhanced bone formation when we coated the Ti device with them and implanted into rat calvaria. Therefore, we have called the Ti-binding bone phosphoproteins as “the implant proteins.” This discovery encouraged us to create a new biomolecule that can simulate the functions of the implant proteins. Since significant characteristics of the implant proteins are the presence of multiple phosphate groups and the occurrence of single cell-adhering RGD sequence, we decided for the first place to phosphorylate chitin and collagen to see whether they acquire or increase Ti-binding ability. Results showed that more than 70% of phosphorylated chitin bound with Ti, and phosphorylated collagen enhanced about 7% of its Ti-binding ability. These modified biomolecules, P-chitin and P-collagen will become highly useful for new development of Ti-related bone regenerative medicine.

Mandibular micrognathia is one of the characteristics of obstructive sleep apnea syndrome. The purpose of this study was to assess the effects of bimaxillary surgery without maxillary advancement on the upper airway using computational fluid dynamics (CFD) results of comparing pre- and post-operative finite element model. Seven female patients with jaw deformity, who underwent two-jaw surgery (Le Fort1 osteotomy and bilateral sagittal split ramus osteotomy; BSSRO) were enrolled. Maxillary was moved for correcting occlusal plane and mandibular was moved to advancement. Pharyngeal airway space and breathing during sleep were evaluated, comparing the periods of 2 days before and 6 months after the operation. The cross-sectional area of the level of the hard palate (HP) and the level of the tip of the uvula (TU), and airway volume of total, HP-TU, and TP- the level of the base of the epiglottis (BE) were increased. AI and AHI in 2 days before and 6 months after were decreased. As the result of nasal ventilation condition, velocity of HP and TU in 2 days before and 6 months after were decreased. We think that it was revealed that movement of the maxilla without advancement did not affect to the morphology and function of airway.