Our aim was to analyze the effect of headgear on upper airway dimension and hyoid bone position on non-extraction patients with Class II division 1 malocclusion. Ninety patients with Class II division 1 malocclusion were included and divided into three groups (Group A: treated with headgears and Class II traction; Group B: performed with Class II traction; and Group C: no treatment). The lateral projection was measured at the beginning and end of treatment. Cephalometric analyses of the dentofacial structure, upper airway dimension and hyoid bone position were performed before and after treatment. The data were analyzed by paired t-test and independent sample t-test. SNA significantly decreased in Group A after treatment (P<0.01), and SNB, ANB and Wits significantly changed in Group A and Group B. L1-MP, L1-NB and Z angle significantly increased, while overjet, overbite and lower lip measurements significantly decreased in Group A and Group B. In upper airway measurements, V-LPW, PNS-V, PNS-U and T-V significantly increased for three groups. Moreover, the hyoid bone position had a change in Group A and Group B. The upper airway dimensions were not decreased by headgear treatment or Class II traction in patients with Class II division 1 malocclusion. Class II traction treatment affected the position of the hyoid bone.
Promotion of bone repair contributes to the shortening of the treatment period and improvement of the therapeutic effect in large bone defects. The purpose of the present study was to determine the optimal condition for the administration of growth factors to facilitate bone repair and explore the significance of angiogenesis in bone regeneration in vivo. Critical-size calvarial defects were created in the parietal bones of adult ddY mice, and the defects were treated with gelatin sponges impregnated with growth factors BMP-2, FGF-2, and HGF, alone or in combination. The bone regeneration at 1, 2, 3, and 4 weeks was evaluated using micro-computed tomography and histological observation. Critical-size calvarial defects were also created in Flk1-GFP mice to analyze angiogenesis in the early phase of bone repair. The proliferation of Flk1-GFP positive endothelial cells during bone repair was quantitatively evaluated using immunohistochemistry for Ki67. Treatment with a combination of BMP-2 and HGF (BMP-2+HGF) significantly induced more new bone formation within the bone defects compared with the other groups. Compared with BMP-2 alone, bone regeneration was rapidly increased by BMP-2+HGF from 3 weeks of the beginning of the treatment. The number of FLK1-GFP and Ki67 double positive cells in the defect areas of mice administered BMP-2+HGF at 1 week was larger than that in those administered BMP-2 alone. These results indicate that the combination of BMP-2 and HGF was markedly efficient in bone regeneration due to the promotion of angiogenesis in the early phase of bone repair.
Human mesenchymal stem cells are capable of differentiating into various cell types and are useful for applications in regenerative medicine. Previous studies have indicated that stem cells can be isolated from dental pulp, and dental pulp exfoliated from deciduous teeth has become a useful alternative for dental tissue engineering because of its higher proliferation rate. For clinical application, it is necessary to culture cells in vitro and to obtain sufficient numbers of cells as quickly as possible. Furthermore, it is necessary to confirm the change in cells cultured in vitro in order to ensure that they have suitable characteristics. In this study, to investigate the changes in human deciduous dental pulp cells cultured with serum-free media, we analyzed cell proliferation, cell morphology and gene expression changes by microarray analysis. We found a high cell proliferation rate in cells that were cultured in STK2 that is a serum-free medium, and cells tended to remain in close contact with one another in cell morphology. In addition, 3248 genes were expressed at >2-fold higher levels in dental pulp cells from deciduous teeth cultured with STK2 compared with medium containing fetal bovine serum for 3 days.
The dental follicle is an ectomesenchymal tissue surrounding developing tooth germ, and contains osteoblastic-lineage-committed stem/progenitor cells. MicroRNA (miRNAs) are small non-coding RNAs that regulate gene expression during stem cell growth, proliferation and differentiation. The aim of this study is to investigate the key regulators of miRNA during osteogenic differentiation in hDFC. We therefore analyzed miRNA expression profiles in hDFC during osteoblastic differentiation. Expression of miR-29a, -29b and 29c decreased in hDFC during osteogenic induction on microarray analysis. Real-time RT-PCR analysis also showed that the expression of miR-29 family members was significantly decreased in hDFC during osteogenic differentiation. The miR-29 family was predicted to target collagen type I alpha 1 and alpha 2 by in silico analysis. When miR-29s were transfected into hDFC, collagen type I production decreased. In addition, hDFC transfected with miR-29 mimics showed delayed mineralization when compared to hDFC transfected with negative control and nontrasfection culture. Our data suggest that miR-29 negatively regulates the osteogenic differentiation/mineralization of hDFC by targeting collagen type I.
The objective of this study was to compare the ability of platelet-rich fibrin (PRF), Bio-Oss and osteoid hydroxyapatite (OHA) in early bone formation by fillingtooth extraction socketsin rabbits. 48 rabbits were randomly divided into 4 groups: group A (PRF), group B (Bio-Oss), group C (OHA), and group D (control). One of the mandibular central incisors was extracted and instantly filled with graft materials. General, radiological and histological observations were evaluated 1, 2, 3, 4, 6, and 8 weeks later. In the first 4 weeks, the quantity of new bone in the PRF group alveolar defects was the best, and the bone mineral density was significantly higher. At the 6th and 8th weeks, the speed of new bone formation in the Bio-Oss group and the OHA group was better than that in the PRF group. Compared with the Bio-Oss group, the OHA group had osteoblasts which were more active and a slightly larger number of bone trabeculae. In addition, the control group was worse than other groups in bone-formation. These results indicate that PRF, OHA and Bio-Oss all can promote osteogenesis in tooth extraction sockets, but the effect of PRF is remarkable at the early time of bone formation. At the later stage, both Bio-Oss and OHA can repair bone defects and guide bone regeneration, and the potential bone formation ability of OHA is better.
The objective of this study was to investigate the possibility of silicon carbide (SiC) foam as an alternative material for porous hydroxyapatite (HA). The characters of two materials were evaluated and compared by a series of in vitro biological tests. The result of the morphology showed that SiC foam provided beneficial structure for cell migration. On the level of primary-osteoblasts proliferation measured by MTT assay and cell cycle analysis showed that the proliferation rate increased in the early stage on HA but in the advanced stage on SiC foam. There was no significant difference between the two materials on the level of cell differentiation detected by alkaline phosphatase (ALP) assay and real-time PCR. All of the results indicated that SiC foam was comparable to HA in terms of biocompatibility and bone conductivity.
The objective of this study was to compare differences between Bio-Oss and CORAGRAF in the rate of bone formation during graft replacement by assessing the density of new bone formation around the implant after sinus floor augmentation. We chose a total of nine systemically healthy patients from dental specialist clinics who planned to have bilateral sinus augmentation prior to implant placement. Bilateral sinus floor augmentation (9 × 2 = 18) was performed with the lateral window technique followed by implant placement (9 × 2 = 18). One site used Bio-Oss and the other coral (CORAGRAF) as the graft material. Radiographic imaging was performed periodically (on the day of surgery, and at 1, 3 and 6 months post surgery) using cone beam computed tomography (CBCT) to measure the bone density at the area of augmented sinus in Hounsfield units (HU). The median of bone density (HU) at 1 month, 3 months and 6 months post surgery for Bio-Oss was higher than for Coragraf. The difference between Bio Oss and Coragraf was statistically significant (p < 0.05). Bio-Oss as a bone substitute in sinus augmentation procedures was superior to Coragraf. However, clinically, the use of Coragraf as a bone substitute in sinus augmentation still gives promising results.
The aim of this study was to compare the diagnostic value of virtual touch tissue quantification (VTTQ) and strain ratio (SR) in differentiating malignant from benign cervical lymph nodes (LNs). The local institutional review board approved the study, and all patients provided written informed consent. A total of 144 LNs in 144 patients were examined with ultrasound elastography (UE) to obtain the SR, and with VTTQ technique to obtain the shear wave velocity (SWV) before taking core biopsies for standard reference. A receiver-operating characteristic (ROC) curve was generated to obtain the area under the curve (AUC) and the optimal cut-off point, after which the sensitivity, specificity, and accuracy of the two techniques were compared. In 144 LNs, 52 LNs were benign and 92 LNs were malignant. With ROC curve analysis, the optimal cut-off point was 2.170 for SR and 2.507 for VTTQ. The sensitivity, specificity and accuracy of SR and VTTQ were 78.26 %, 82.69 %, 79.86 % and 89.13 %, 90.38 %, 89.58 %, respectively. Specificity and accuracy were significantly higher for VTTQ than for SR (P<0.05). VTTQ is more accurate than SR in differential diagnosis of benign and malignant cervical LNs.
The temperature-sensitive triblock copolymer poly-(D, L-lactic acid-co-glycolic acid) (PLGA)-polyethylene glycol (PEG)-PLGA (PLGA-PEG-PLGA) is an FDA-approved material that has the ability to provide a sustained release of drugs and/or proteins. Platelet-rich fibrin(PRF)is second generation platelet concentration that contains growth factors such as transforming growth factor-β1 (TGF-β1), platelet derived growth factor-AB (PDGF-AB), and insulin-like growth factor-I (IGF-I). These growth factors affect the migration and proliferation of diverse cell types, including endothelial cells, smooth muscle cells, and osteoblast-like cells. This study sought to combine the hydrogel into scaffolds in order to serve as a sustained release system for PRF-derived growth factors. Poly (lactic-co-glycolic) acid (PLGA) and nano-hydroxyapatite (nHA) were used to prepare the hydrogel-containing scaffolds with the PRF-derived growth factors. We then investigated the effects of the hydrogel on modulating the activity of osteoblasts in vitro. We indicated that the hydrogel (Gel) was well-distributed in the inner surface of scaffolds, which themselves exhibited relatively interconnected pores with uniform sizes. The addition of the hydrogel didn’t affect their inherently high porosity. In vitro release tests indicated that the system containing nHA/PLGA/Gel/PRF provided for a slow and sustained release of PRF-derived growth factors. The results from our in vitro studies indicated that the MG63 cells cultured with both scaffold media extracts did not appear to have cytotoxic responses, and the nHA/PLGA/Gel/PRF system could improve the adhesion and proliferation of MG63 cells when compared to controls (p < 0.05). This in vitro evaluation suggests that the hydrogel-scaffold system is suitable as a model for bone tissue engineering, and that it allows for the sustained release of growth factors to improve bone reconstruction.
Plasma rich in growth factors (PRGF) had been used in regenerative therapy such as soft tissue and newly bone formation. However, there has been little basic research into the efficacy of PRGF in bone regeneration. In this study, we evaluated the efficacy for new bone formation by transplantation of PRGF onto rat calvaria. The osteogenic potential was evaluated by histologic findings, immunohistochemistry and bone formation analyzed with micro-computed tomography (micro-CT). PRGF was prepared by centrifugation of rat whole blood (WB), and then was activated using 10% calcium chloride solution. The activated PRGF transplanted within a polytetrafluoroethylene (PTFE) tube was transplanted onto calvarial bone of rats. Histological observation demonstrated that PRGF group showed newly formed bone in a wide range. Immunohistochemistry showed Runx2, Osterix, Bone Alkaline Phosphatase (BAP) and Osteocalcin expressed in PRGF group during the early stage of bone formation. Micro-CT showed that PRGF group promoted an increase in bone volume which compared to control group. We concluded that PRGF has more capacity for bone regeneration, and PRGF may be useful in bone regeneration treatment.
The aim of this study was to compare bone augmentation height and mechanical strength after implantation of tetrapod-shaped granular artificial bone (Tetrabone® [TB]), hydroxyapatite granules [HA], α-tricalcium phosphate paste [Pα] or autogenous onlay bone grafts (veneer graft [VN]). Forty-five 6-week-old male Wistar rats were used. The graft materials were implanted in the left tibial subperiosteal pocket. Bone augmentation was evaluated by computed tomography (CT), mechanical testing and histological observation immediately after surgery (0 weeks) and 4, 8, and 12 weeks later. The augmentation height was measured in CT images and the proportion of bone augmentation was calculated as the ratio of 12 weeks/0 weeks. TB aggregates were smooth in shape compared with HA aggregates. The augmentation height was significantly higher in the TB group than in the VN group. At 12 weeks, bone stiffness was significantly higher in the TB group than in the HA and Pα groups, and very similar to that in the VN group. TB presented good shape stability and mechanical strength. TB might be useful for bone augmentation of flat bone area as compared with other currently used artificial graft materials. Future studies should focus on the clinical application of TB grafts.
Diabetes mellitus (DM) is one of the main etiologies and risk factors for periodontal disease, and is an important concern in periodontal medicine. It has been reported that high glucose concentrations mediate proliferation, differentiation and production of inflammatory cytokines on mesenchymal cells, but there are few reports on periodontal regenerative therapy in type II DM patients. The aim of this study was to examine the biological effects of high glucose conditions on GK rat (type II model) bone marrow mesenchymal cells (GK rat BMMSC). Cell culture experiments were performed with GK rat BMMSC. The effects of glucose at four concentrations (5.5, 8, 12 and 24 mM) were determined by examining cell proliferation, differentiation and production of inflammatory cytokines; the latter three concentrations are higher than the normal physiological glucose concentration, represented by 5.5 mM. High concentrations of glucose promoted proliferation and inhibited hard tissue differentiation and calcification of GK rat BMMSC. Differentiation correlated inversely with the expression of inflammatory cytokines, represented by IL-6. Our data suggest that high extracellular glucose concentrations promote proliferation and inhibit hard tissue differentiation and calcification in periodontal regeneration by causing an inflammatory response dependent on cytokines including IL-6.
The purpose of this study was to investigate the efficacy of a mixture of biphasic ceramic biologic bone (BCBB), bone morphogenetic protein (BMP), and basic fibroblast growth factor (bFGF) in repairing femoral head necrosis (FHN) and to explore new FHN treatment. BCBB was modified and mixed with BMP and bFGF to obtain the complex used in this study. The FHN models were implanted with BCBB/BMP mixture, BCBB/BMP/bFGF complex, and cancellous bone autografts, respectively. The control group received no treatment. A series of examinations, including anatomical observation, X-ray examination, histological analysis, and vascular immunohistochemical staining, were carried out 2 w, 4 w, 8 w, and 12 w after operation to assess the repairing of FHN in these groups. Anatomical observation and X-ray examination showed that the complex of BCBB/BMP/bFGF led to the repair of the injuries in these rabbit FHN models, to a comparable level with cancellous bone autografts. Histological analysis indicated that BCBB/BMP/bFGF complex could induce osteoinduction, which would enhance bone remodeling in these models. Furthermore, vascular immunohistochemical staining revealed that BCBB/BMP/bFGF complex dramatically stimulated the revascularization in FHN models, contributing to the injury recovery process. BCBB/BMP/bFGF complex is able to induce obvious osteoinduction and revascularization in rabbit FHN models, to a comparable level as observed with the cancellous bone autografts, thus providing a promising treatment for the disease.
This study characterized the molecular mechanisms of the effects of protamine-hydrolysate peptides (p-h peptides) on skin wound healing in rats by analyzing the transforming growth factor (TGF)-β signaling pathway. TGF-β was expressed in experimentally wounded skin tissues in fibroblasts and in keratinocytes. In p-h peptides-treated animals, the skin wounds exhibited an increased expression of TGF-β and of TGF-β target genes compared with control saline-treated skin wounds. Treatment with p-h peptides accelerated wound epithelialization and induced protein expression of TGF-β, CTGF and VEGF. The expression of tumor necrosis factor (TNF)-α was decreased in fibroblasts of p-h peptides-treated skin wounds. In addition, treatment with p-h peptides significantly enhanced the phosphorylation of Smad3 and Smad4 in fibroblasts and also elevated the phosphorylation of Stat3 in skin wound tissues. In conclusion, treatment with p-h peptides activated the Smad-dependent TGF-β signaling pathway, enhanced the differentiation of myofibroblasts and accelerated skin wound closure.
Quality of life (QOL) is an important factor to take into consideration in the treatment for giant head and neck tumor. The purpose of this study is to evaluate surgical treatment impact on the quality of life in 57 cases of patients with a giant tumor in the head and neck region. The patients were divided into two groups: a benign group (21 cases; 36.84 %) and a malignant group (36 cases; 63.16 %). QOL was assessed using the Performance status scale for head and neck cancer patients (PSS-HN) and the University of Washington Quality of Life (UW-QOL) questionnaires before and 1 month, 6 months, and 12 months after surgical treatment respectively. Fifty-seven of the 71 questionnaires (80.28 %) were completed for both PSS-HN and UW-QOL at one or two times during the treatment and follow-up periods. The appearance was improved in giant benign head and neck tumor group, but deteriorated significantly in malignant group. The QOL in patients deteriorated by surgical treatment but it could be improved over time. PSS-HN, in conjunction with UW-QOL, can provides a valuable tool for the assessment of quality of life in giant tumor of head and neck before, during and after treatment with surgery.
Ozone is a potent oxidative gas and its bactericidal effect is exploited in dental practice. However, the half-life of ozone is extremely short, which limits its ability to exert bactericidal effects on cells. Therefore, we focused on ozone gel, which is composed of a glycerin solution containing ozone, a recently developed technology, in vivo. In the course of our study, we evaluated the safety of ozone gel application to the skin and eye, as well as its effects on hemostasis and antimicrobial effects. In this study, we found that ozone gel was nontoxic to the oral mucosa. Our results suggest that ozone gel represents a clinically agent for periodontal diseases and peri-implant diseases.