Bone tissue engineering is expected to be utilized clinically as a patient friendly strategy instead of autogenous bone grafts, and bone morphogenetic protein (BMP) is applying for bone regeneration. BMPs have been found in the 1960s and their gene cloning has been succeeded two decades later, which revealed that BMPs were members of TGF-β superfamily. BMPs have critical functions in embryonic development and tissue generation, and BMPs induce bone formation in mammals though its primary functions are different. Subcutaneous implantation of BMP in rodent reproduces endochondral bone formation occurred in embryogenesis. Recombinant human BMPs are applied for spinal fusion and non-union fracture repair and also utilized in the field of oral and maxillofacial surgery such as sinus floor augmentation. BMP regenerates mandible bone after its segmental resection in non-human primates as a preclinical trial. However, the results were not conclusive in clinical studies especially in elderly patients. A high dose of BMP is required to restore large bone defects, but it may also induce life threatening significant edema. The further studies are necessary for effective and safe application of BMPs to restore large bone defects.

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A granular bone substitute composed of alpha tricalcium phosphate, chondroitin sulfate and disodium succinate is biocompatible in vivo. The aim of this in vitro study was to analyze cellular aspects related to bone regeneration. The response of MG63 and L929 cells to liquid extracts of the respective material was reported. Viability and integrity of the cell membrane were determined by MTT and trypan blue exclusion assay. Cytoskeletal changes were followed by phalloidin staining. Expression of apoptotic, mitogenic and osteogenic differentiation genes was detected by RT-PCR. Supernatants obtained at 24 hours of extraction, but not later, reduced formazan formation in L929 and MG63 cells (p<0.05). Also sodium chondroitin sulfate at 10 % and disodium succinate at 2.5% significantly decreased cell viability (p<0.05). Moreover, we observed impaired integrity of the cell membrane and cytoskeletal changes. Expression of mitogenic genes was partially reduced while apoptotic and differentiation genes were unchanged. Liquid extracts of αTCP and βTCP failed to cause any substantial effects. Thus, the composite bone substitute can cause an early, but temporary cell necrosis. Since bone regeneration is initiated by a transient catabolic phase, the observed effects are in line with this biological principle.

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Biocompatibility and resistance to biodeterioration of materials has been studied using various approaches, including the analysis of various markers of exposure, both in vitro and in vivo. The possible release of trace elements during orthodontic treatment and their potential toxicity to patients have been an increasing concern. The wide range of appliances routinely used during orthodontic treatment is typically made of alloys which may contain cobalt, chromium, iron, nickel, and titanium, of which the major concern is nickel. Nickel concentrations in humans undergoing orthodontic treatment have been assessed in many investigations, although few have specifically examined urine specimens. Urinary nickel concentrations can reflect systemic levels in whole organisms, and as a non-invasive means of study, urine analysis can easily achieve the compliance of participants and guardians. In addition, the predominant metabolic route of nickel is through the kidneys. Therefore, urinary samples are seen as a good indicator for monitoring trace metals released from orthodontic appliances. According to the literature, metal ions are released only in the initial stage of the treatment. Thus, the duration of our study was limited to the first 6 months of treatment. Since urinary nickel levels of adolescents in the initial period of fixed orthodontic treatment are being investigated and reported for the first time in this paper, the aim of our study is to quantitatively evaluate urinary nickel levels and further to summarize the dynamic metabolic regularity of systemic nickel for adolescents in the initial period of fixed orthodontic treatment.

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Osteoclasts, the bone-resorbing cells, are unique multinucleated cells which show the ability to destroy the bone tissue through dissolution of hydroxyapatite and degradation of organic matrix components. Fetal Bovine Serum (FBS) contains a large number of nutritional and macromolecular factors, it’s widely used as a cell culture supplement. Previous studies have found that FBS is essential for cell growth and it is also a potent inducer of osteoclast formation. However, relatively little is known regarding the mechanism of this effect. The aim of this study was to further explore the potential role of FBS on osteoclast formation and its mechanism. RAW 264.7 cells were cultured in medium with different FBS concentrations (10 %, 5 %, 1 %). The experiments were designed and performed including Tartrate-resistant acid phosphatase (TRAP) staining, Immunostaining, Transwell migration assay, Real time polymerase chain reaction (RT-PCR), and Western blot analysis. The results demonstrated that FBS promoted osteoclastogenesis in suitable concentrations by regulating migration of osteoclast precursors and expressions of TRAP and Cathepsin K.

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The purposes of this study were to establish a unilateral ureteral obstruction renal fibrosis model and determine the pathological changes in renal interstitial. Expression of matrix metalloproteinase-2 and tissue inhibitor of matrix metalloproteinase-2 after tetramethylpyrazine treatments were determined.Thirty-two female Sprague Dawley rats were randomly divided into 4 groups: a sham group, model group, tetramethylpyrazine group and valsartan group. The rats in the model group, tetramethylpyrazine group and valsartan group were operated with left ureter ligation to establish the unilateral ureteral obstruction model. Rats in the tetramethylpyrazine group were given intragastric administration 1 day before surgery. The pathological changes of the obstruction renal tissues were examined by hematoxylin-eosin staining and Masson staining. Immunohistochemistry and reverse transcription-polymerase chain reaction were applied to detect the protein and mRNA expression levels of matrix metalloproteinase-2 and tissue inhibitors of matrix metalloproteinase-2. Tetramethylpyrazine could significantly reduce the expansion and contraction of the tubular, the proliferation of renal interstitial fibrous tissue and inflammatory cell infiltration. Compared with sham group, the protein and mRNA expression levels of matrix metalloproteinase-2 and tissue inhibitors of matrix metalloproteinase-2 were significantly increased in model group (p< 0.05). The protein and mRNA expression levels of matrix metalloproteinase-2 and tissue inhibitors of matrix metalloproteinase-2 in tetramethylpyrazine group were lower compared to the model group (p < 0.05). Tetramethylpyrazine could relieve the renal interstitial fibrosis by inhibiting the expression levels of matrix metalloproteinase-2 and tissue inhibitors of matrix metalloproteinase-2.

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Currently the most common method of reconstructing a ruptured anterior cruciate ligament (ACL) is by using bone-patellar tendon-bone (BPTB) or semitendinosus, gracilis tendon autografts. Although good results are reported, donor morbidity continues to be a problem. To overcome these complications, synthetic grafts have been investigated. However, to date no prosthetic graft has been developed as an alternative to patellar or hamstring tendon autografts. The aim of the present study was to assess the biocompatibility of nitinol in rat knee joint spaces and distal femoral bones. Ten male, healthy Wistar albino rats, weighing between 300-350 g, were used. The right knee joint of each rat was reached by medial longitudinal parapatellar dissection. The femur distal was penetrated by a size 0.5 mm of Kirshner wires. Twenty nitinol wires were placed in the bone tunnel (0.125 mm in diameter and 5 mm long). In addition one nitinol wire was placed in the joint space. Following hemostasis, the layers were closed with interrupted sutures. The same procedure was repeated for the left side without placing any nitinol wire. The rats were allowed unrestricted weight bearing. Two animals died of unknown reasons during follow-up. The remaining rats were sacrificed 8 weeks after surgery. The knees were removed by careful dissection and the nitinol wires were removed. The sections taken from these specimens were stained with standard hematoxylin and eosin and with Mason trichrome and examined under the light microscope. The bone tunnels were filled with osteocytes and chondrocytes. In two specimens of the nitinol group, moderate synovitis was detected. The synovitis rate in the study group was found to be statistically insignificant. In conclusion, the short term biocompatibility of nitinol in the rat knee joint space and femoral tunnel was found to be within acceptable limits.

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Objectives: To compare cranial base morphology in different vertical facial types and explore their regularity. Methods: Sixty-nine Class I patients, aged 10-15 years, were selected from the Department of Orthodontics, School of Stomatology, China Medical University. They were divided into three groups: high angle group (12 males and 10 females), average angle group (11 males and 13 females) and low angle group (14 males and 9 females). Single factor analysis of variance, as well as paired t-test, was used to analyze the differences of the measurements among the three groups. Results: Significant differences could be found in cranial base angle, sella angle, Ba-SE-FMS angle, posterior cranial base angle and the length of SO-Ar. The gradual decrease of cranial base angle, sella angle and Ba-SE-FMS angle from low angle to high angle showed significant differences; moreover, the posterior cranial base angle and the length of SO-Ar gradually decreased and also showed significant differences. The length of posterior cranial base in the high angle group was shortest; however, there was no statistically significant difference between the average angle and low angle groups. The anterior cranial base angle of high angle patients increased; there was no statistically significant difference between the low angle and the average angle patients. Conclusions: The structure of the cranial base in different vertical facial types presents certain regularity and it could be considered that the growth of the cranial base is involved in the development of different vertical facial types. The posterior cranial base seems to have a significant influence on the formation of vertical facial types.

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The purpose of this study was to examine the incidence of root canals with ramifications and accessory root canals close to the apical area of the palatal root of maxillary first molars, and to classify them based on morphology. Using Micro-CT, we created images of 90 extracted Japanese maxillary first molars that were free of caries and other anatomical defects, and conducted three-dimensional observation and measurements in order to classify root canals with ramifications and accessory root canals. None of the root canals in palatal roots of maxillary first molars were completely separated, and all of them were single canals. As for the incidence of root canals with ramification, we found that Type I-a, in which there were no accessory root canals, comprised 65.6 %, while Type I-b, which showed apical ramifications, comprised 31.1 %, and Type I-c, which had lateral canals, comprised 3.3 %. Observation of the cross-section morphology of the root canals revealed strong buccolingual constriction at the root canal orifice, but other than that, the canals had an elliptical shape with a large mesiodistal width. Maxillary first molar palatal roots contain single canals, but strong constriction is observed at the root canal orifice, and accessory root canals are frequently observed in the apical area. These findings indicate the necessity for adequate mechanical and chemical enlargement of the root canal and orifice.

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To investigate the effects of the histone deacetylase inhibitor LBH589 on the osteogenic differentiation of stem cells from the apical papilla (SCAPs) in vitro. Mesenchymal stem cells were isolated from the apical papilla with patient consent. MTT assays and flow cytometric analysis of annexin V were performed to evaluate the effect of LBH589 on the proliferation and apoptosis of the SCAPs. SCAPs were cultured in osteogenic conditioned alpha minimum essential medium (α-MEM). After stimulation with different concentrations of LBH589, alkaline phosphatase staining, alkaline phosphatase activity analysis, and alizarin red staining were performed to detect the osteogenic effects of LBH589. In our in vitro study, cells treated with LBH589 showed significantly enhanced alkaline phosphatase staining, alkaline phosphatase activity, and calcium nodule formation. This study demonstrated that, as a global histone deacetylase inhibitor, LBH589 has the potential to promote the osteogenic and dentinogenic differentiation of stem cells from the apical papilla.

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The objectives of this study were to screen for the better Oligonucleotide (ODN) that promotes the proliferation of human bone-marrow mesenchymal stem cells (hBMSCs) and to investigate the mechanism of action of the ODN that has the greatest effect on the hBMSCs cell cycle. hBMSCs were isolated, cultured to the third passage and subjected to osteogenic, adipogenic and chondrogenic induction in order to examine their capacities for multi-differentiation. The hBMSCs were seeded at different plating densities (3.0×10³/cm², 6.0×10³/cm², 1.2×10⁴/cm², 2.4×10⁴/cm²) and tested for seven consecutive days to determine the better plating density. A total of 12 experimental groups and 1 control group of hBMSCs (4 replicate wells in each group) were established and treated with ODN types MT01, FC003, or SAT05f at concentrations of 0.5mg/l, 1.0 mg/l, 2.0 mg/l or 4.0 mg/l; the control group was treated with an equal volume of PBS. Proliferation of hBMSCs was determined for 3 consecutive days after treatment via CCK-8 assay. The type and concentration of ODN that had a significant facilitatory effect on hBMSCs proliferation was selected and cell cycle analysis was done on days 1, 2 and 3 after ODN treatment; control groups were treated with an equal amount of PBS. The expressions of cyclin A, cyclin D1, cyclin dependent kinase (CDK) 2 and CDK 4 in hBMSCs were measured on day 2 after treatment using fluorescent quantitative real-time PCR. The isolated and cultured hBMSCs were found to have osteogenic, adipogenic and chondrogenic differentiation capacities. The better cell growth curve was found to occur at a plating density of 6.0×10³/cm². Optical density was significantly increased in hBMSCs treated with 0.5 mg/L FC003 on day 1 (P<0.01) compared to the control group. Optical density was significantly decreased on day 1 after treatment with 1.0 mg/L and 4.0 mg/l of SAT05f (P<0.01 and P<0.05, respectively). Optical density was significantly increased on days 1, 2 and 3 after treatment with a final concentration of 2.0 mg/L of MT01 (P<0.01, P<0.05, P<0.05, respectively). The percentage of cells in phase G0/G1 was significantly reduced, and the percentage of cells in phases S and G2/M was significantly increased (P<0.01) after treatment with 2.0 mg/l MT01 compared to the control group. Furthermore, the expressions of cyclin A, cyclin D1, CDK 2 and CDK 4 were significantly elevated (P<0.01) compared with the control group. In conclusion, a 2.0 mg/l concentration of MT01 significantly promotes hBMSCs proliferation as evidenced by the decrease in the percentage of cells in phase G0/G1 and the increase in the percentage of cells in phases S and G2/M. The underlying molecular mechanisms may include, but are not limited to, elevated expressions of cyclin A, cyclin D1, CDK 2 and CDK 4.

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Lateral cephalometric analysis is an integral part of orthodontic diagnosis and treatment planning. The usual practice is to compare the cephalometric analysis of the patient with the established normal values. Since craniofacial morphology varies among different populations therefore it becomes important to establish the cephalometric norms of all cephalometric analyses, for every population. The aims of this study were to evaluate the validity of newly introduced cephalometric analysis using W angle and YEN angle in Pakistani and Bangladeshi samples and to compare both populations with commonly used sagittal measurements. In this study 200 lateral cephalograms of Bangladeshi population and 209 of Pakistani population were traced for ANB, Wits appraisal, Beta angle, W angle and YEN angle. Patients were divided into skeletal Class I, II and III groups. A significant difference was found in all performed measurements among skeletal groups in both the samples (p<0.001). Mean values of ANB, Wits appraisal and YEN angle differed significantly between both the samples in class I and class II subjects (p<0.05). No statistically significant difference was found in Beta angle and W angle values. The norm for W angle was established for the Pakistani (54.5±3) and Bangladeshi population (55±3). YEN angle norm for the Pakistani population was found to be 119.5±3, and for the Bangladeshi population it was 120.5±3. These results suggest that all the performed analyses are valid and can be used to diagnose skeletal discrepancies and diagnosis based on single analysis is insufficient. Bangladeshi and Pakistani populations differ in craniofacial morphology; therefore their own cephalometric norms should be followed for treatment of patients belonging to their respective populations.

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The salivary glands produce saliva, which helps keep the mouth and other parts of the digestive system moist. Mammals normally have major and minor salivary glands, and the major salivary glands are composed of three large salivary glands including the parotid, submandibular and sublingual glands. There have been many morphological studies of the submandibular glands of mammals. However, there have been only a few reports on the submandibular glands of opossums. The present study was a histological investigation into the morphology of the submandibular glands in the gray short-tailed opossum. Submandibular glands were obtained from three opossums. All specimens were fixed in 10% neutral formalin solution, and paraffin sections were made by usual methods. They were stained with hematoxylin and eosin, PAS-alcian blue pH 2.5 and mucicarmine.
Macroscopically, the submandibular glands were located at the posterior and inferior portion of the tongue in the anterior neck space. Microscopically, the submandibular glands were composed of many lobules separated by thin fibrous septa. Submandibular glands consisted of serous and mucous acinar cells, showing mixed glands. Serous acinar cells had basophilic cytoplasm and numerous secretory granules and their cytoplasm was partly stained with PAS. Mucous acinar cells had pale-staining cytoplasm stained with alcian blue and/or PAS and mucicarmine. Conclusively, the present study demonstrated characteristic features of the submandibular glands of the gray short-tailed opossum, and it revealed histological data both in accordance with and different from that for the submandibular glands of mammals.

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In Dhaka 2013, autografts of demineralized dentin matrix (DDM) were first used as bone regenerative therapy with two patients in Bangladesh. In Case 1, a 29 year-old male presented with an infected periapical lesion involving #11 and #12. Root canal treatment followed by periapical surgery were done to remove the lesion. Tooth-derived granules were prepared from a vital non-functional tooth (#38) by hand-operated crush method, demineralized in 2 % HNO₃ for 30 min and washed vigorously. DDM was grafted in the bone defect after the extirpation of the lesion. At 1 year after DDM graft, post-operative radiography indicated excellent bone healing by remodeling with dentin matrix. The pathological diagnosis was radicular granuloma. In Case 2, a 20 year-old female presented with a mesially inclined impacted 3^rd molar (#48). Extraction of the impacted tooth and the autograft of the DDM were done simultaneously. Post-operative radiographs showed the extracted socket healed fully with new bone. The patient-own DDM granules from non-functional teeth could be recycled as osteoinductive materials for local bone regeneration. This works suggest that dentin might become a realistic alternative biomaterial to bone.

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The use of auto-tooth bone grafts fabricated from patients’ own extracted teeth has become possible due to the development of tooth banking procedures. The Korea Tooth Bank (KTB), established in Seoul in 2009, is one such tooth-banking facility that can procure and store teeth, and then process them into bone graft substitutes. Another is the Hospital Tooth Bank (HTB) at Seoul National University Bundang Hospital (SNUBH), established in 2010 for performing storage and grafting of auto-tooth bone grafts based on experimental and clinical research. Extracted teeth are sent to the above-mentioned facility units and then delivered back to the patients for clinical use, and thus the safety of the auto-tooth bone graft materials as well as the clinical effectiveness must be guaranteed through proper quality assurance (QA) procedures. For the purpose of this investigation, we analyzed written documents for QA at KTB, and we performed histopathologic and microbiologic examinations against the banked tooth materials at the HTB. The results suggest that the tooth banking systems at both KTB and HTB sufficiently ensure patient safety.

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The aim of this study was to establish a model, which can be used to investigate the response of periodontal tissues to excessive occlusal loading in mice by observing histopathological changes. The experiment was performed on ten 7-week-old ddY male mice. Under general anesthesia by intraperitoneal injection pentobarbital sodium, a micro-plus-screwpin (head part, 1.7mm in diameter, thickness 0.5mm thickness) was screwed into the pulp cavity of the upper-left-first molar. R_mCT images of the experimental site indicated the occlusal contact position between the upper- and lower-left-first molars during the experimental periods. A micro-plus-screwpin was maintained at a constant position on the occlusal surface throughout the experimental period. Histopathological changes of the periodontal ligament at the furcation lesion of the lower-left-first molar and its surrounding periodontal tissues were observed under a light microscope. The densities of deeply dyeing cells in hematoxylin staining with a round-shaped nucleus were increased in the periodontal ligament, with a peak effect of day 4. Multinucleated giant cells appeared in the central lesion of the periodontal ligament on day 7. The distribution of resorption on the surface of both of the cementum and the alveolar bone was accompanied by multinucleated giant cells, which expanded rapidly from day 7 to day 14. These results showed that histopathological changes of periodontal tissues to excessive occlusal load were observed at the furcation area of molar teeth. The present method confirmed the effectiveness of the experimental model to examine the occlusal trauma on periodontal tissues produced by excessive occlusal load.

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