Three dimensional computed tomography (3D-CT) has been used widely in diagnosis and treatment for patients with jaw deformity. In present study, the author assessed the value of 3D-CT in jaw osteotomies. Anatomic measurement data from 3D-CT was used to guide surgical treatment. 42 patients with dentofacial deformity (28 females and 14 males) were selected as study group who underwent Le Fort I osteotomy with bilateral sagittal split ramus osteotomy or intraoral vertical ramus osteotomy (IVRO). The patients in study group were observed on 3D-CT acquired with a slice thickness of 1.25mm between June 2006 and June 2010. 20 patients were selected as control group who underwent the same osteotomy between June 2006 and June 2010. Patients in control group underwent X-rays such as panoramic film and cephalometric radiography, but no anatomic measurements. The following anatomical data was measured for study group: 1. the distance from lingula mandibulae to anterior border of ramus, posterior border of ramus and inferior border of simoid notch; 2. the width between the outer mandibular canal and buccal side cortical bone at three location planes: the mandibular foramen plane (MFP), the mandibular angle plane (MAP) and the intermediate plane (MIP) between MFP and MAP; 3. the height of bilateral pterygomaxillary junction; 4. the anteroposterior distance from bilateral anterior nasal aperture to canalis pterygopalatinus. According to the anatomical data from 3D-CT, surgeons can take measures to avoid some complications during operation. As for study group, 42 patients satisfied with operation didn’t experience severe complications such as avascular necrosis, unexpected fracture and haemorrhage and so on. As for control group, 3 patients suffered from mandible fracture and 1 patient descending palatine artery blooding. All the results showed that 3D-CT was valuable for jaws osteotomies.

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Titanium fiber web (TW), which is produced by sintering intertwined thin titanium fibers, is non-degradable three-dimensional scaffold material graft substitutes.TW has sufficient stiffness and elasticity for role and is bone compatible and easy to handle during surgery. We aimed to evaluate the influence of the differences of porosities of TWs on bone formation inside the TWs. Three types of TWs with different volumetric porosity, 60%, 73% and 87%, with a fiber diameter of 50μm were used. The TW was height of 4 mm, width of 4mm and thickness of 2 mm. SEM views of TWs indicated that the mean pore size of the TW was approximately 100-150 μm for 60% porosity TW, 200-250μm for 73% porosity TW and 300-350 μm for 87% porosity TW. Each TW was inserted into the cortical bone of rabbit tibiae. After 12 weeks of implantation, histological evaluation was performed. There are no distinct differences on the overall cortical bone response to TWs with three different porosities. Some TWs are embedded in the cortical part of tibiae of rabbits. Almost complete bone ingrowth was observed in the space of all TWs. For TW with 60% porosity, bone formation in the part of TW which is located in medullary cavity was recognized. It is concluded that TW is expected to be useful as a non-resorbable three-dimensional scaffold in regenerative medicine. More researches for clinical application of TW are the next series of our studies.

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The aim of this study was to evaluate the effects of pulsed CO₂ laser irradiation on human pulp fibroblast.
Pulp fibroblasts were collected from extracted human third molars. The fibroblasts were kept in humidified atmosphere at 37°C with 5% CO₂. Experiments were performed with cells not exceeding 7 passages. Pulp fibroblast cells were irradiated with CO₂ laser device (BEL-LUXER super pulse laser). Laser irradiation was applied continuously with a wave of E16 mode for 90 sec. The specimens were cultured (10-day) with or without CO₂ laser irradiation. Laser-irradiated medium was separated from cell culture dish and the protein, calcium and phosphate were quantified from the supernatants. After cultivation, fibroblast count was determined using a hemocytometer (Bright-line Hausser Scientific Horsham, PA USA). Total RNA was extracted from fibroblast cells and RT-PCR analysis was performed. The protein concentration increased in samples treated with CO₂ laser irradiation. The number of fibroblast cells in laser irradiated group was significantly higher than the untreated group (n=8, t-test, p‹0.01). HSP27 and 60 mRNA expressions were detected in both untreated and laser irradiated groups. However, HSP 70 was found only in laser irradiation group. OC was presented in both untreated and laser irradiated groups. Other markers of calcification were not detected in all specimens.
It was suggested that pulsed CO₂ laser irradiation tends to accelerate cell proliferation and induces HSP70 expression.

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Wnt is involved in odontoblast and ameloblast differentiation and matrix protein expression in dentin and enamel, but there have been only a few reports on Axin2 in the Wnt signaling pathway. Axin2 promotes Smad3 activation in the transforming growth factor beta (TGF-β) signaling pathway, and the presence of cross-talk between the Wnt and TGF-β signaling pathways has been reported, but there have been no reports on that in odontogenic cells. Thus, we examined immunohistochemically the factors in the 2 signaling pathways using serial sections of rat first molar germ at embryonic day 19 and 10 days after birth to investigate whether there is cross-talk between the 2 signaling pathways through Axin2 and Smad3. Factors in the Wnt signaling pathway: Wnt10, Dishevelled (Dvl), and Axin2, and those in the TGF-β signaling pathway: TGF-β receptor 1 (TGF-β-R1), Smad3, and its active type, phosphorylated Smad3 (p-Smad3), showed similar immunoreactions; in detail, odontoblasts possessing secretory function, rather than dental papilla cells and preodontoblasts, and secretory-stage ameloblasts, rather than inner enamel epithelium, showed stronger reactions, whereas the reaction of maturation-stage ameloblasts was very weak. In addition, the reaction of Axin2 was completely consistent with that of pSmad3, and odontoblasts and secretory ameloblasts showed the strongest positive reactions. Accordingly, it was suggested that the TGF-β signaling pathway as well as Dvl- and Axin2-mediated Wnt10 signaling pathway may are involved in odontoblast and ameloblast differentiation and the secretory function of these cells. In addition, the reaction of Axin2 was completely consistent with that of pSmad3, and odontoblasts and secretory ameloblasts showed the strongest positive reactions, suggesting that a cross-talk between the 2 signaling pathways through Axin2 and Smad3 may be involved in the odontoblast and ameloblast differentiation and secretory function of these cells.

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The purpose of this study was to report experience of Department of Oromaxillofacial-Head and Neck Surgery, Department of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University in the treatment of ameloblastoma in children and young people and to discuss the treatment regimen. And review the world literature on the treatment of ameloblastoma in children and adolescents from 1986.A total of 227 patients were recorded of which, 30 (13.21%) were below the age of 18 years, with a diagnosis of ameloblastoma in our hospital between January 1994 to June 2011. The study included the patient’s age, gender, lesion location, clinical features, radiographic appearance, treatment, recurrences and course of follow-up.30 cases of children and adolescents ameloblastoma patients, 19 males and 11 females, male to female ratio was 1.7:1, the average age of 14.5 years. 28 cases of lesions in the mandible, only 2 cases occurred in the maxilla. Clinical typing included 21(70%) solid type and 9(30%) unicystic type. 7 (23.33%) patients were treated with radical treatment, 23 (76.67%) cases underwent conservative method. 7 (23.33%) cases were recurrent, of which 6 cases of recurrence once, and 1 patient had 2 recurrences. Desired results can be reached in the treatment of ameloblastoma in children and adolescents using conservative measure, and can reduce the incidence of maxillofacial deformity and dysfunction. Determine the treatment required to consider many factors. Patient compliance and complete follow-up are important.

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Aging is a complex biological process driven by a selective class of molecules and pathways that affect the overall deterioration of physiological functions to increase the risk of aging. Bone formation steadily declines with age, resulting in a significant loss of bone mass, and reactive oxygen species (ROS) are thought to be a major contributor to the aging process. In our previous study, H₂O₂ treatment significantly reduced the bone nodule formation rate in the preosteoblast cell line MC3T3-E1.
In this study, the effect of H₂O₂ treatment as cellular ageing of osteoblasts on gene expression in MC3T3-E1 cells was examined using DNA microarray technology. Many genes were altered those gene expressions by H₂O₂ treatment. Among these genes, the reduction of the mRNA signal of hyaluronan mediated motility receptor (MHHR) was observed in DNA microarray analysis results. Significantly lower mRNA levels in the gene was confirmed by reverse transcription polymerase chain reaction (RT-PCR) and real-time PCR. Since MHHR involved in bone formation through the stimulation of proliferation and differentiation of osteoblasts, the reduction of gene expression of MHHR by H₂O₂ may be involved in the molecular mechanism of the decline in bone formation with aging.

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Objective of this study is to investigate whether diet or sex influences calcification of the tendon in the Mop-3/Bmal-1 gene knock-out mouse (Bmal-1 knock-out mouse) by comparing “in vivo” micro-computed tomography imaging, soft-tissue X-ray imaging, and histologic evaluation as the ‘gold standard’.
23 mice were placed into 8 groups according to genetic background, diet and sex. They underwent micro-CT imaging at magnifications of ×1.5, ×4.0, and ×10.0, and soft-tissue X-ray imaging. We compared 37 tendons in each of the 8 groups that showed calcification on micro-CT ×10.0 and on histologic evaluation.
On micro-CT×1.5 images, 8 of the 21 joints of Bmal-1 knock-out mice showed calcification, and calcification was seen on micro-CT×4.0 images in 19 of 21 joints, and on micro-CT ×10.0 and SOFTEX, calcifications were seen in 20 of the 21 joints. For detecting calcifications, the diagnostic accuracy of micro-CT×1.5 was 0.68, that of micro-CT ×4.0 was 0.97, that of micro-CT ×10.0 and SOFTEX was 1.00. Regarding sex and diet, calcification was seen in 5 of 5 joints from males fed a high-fat diet, 4 of 4 joints from females fed a high-fat diet, 5 of 5 joints from males fed a regular-fat diet, and 6 of 7 joints from females fed a regular-fat diet.
High-speed micro-CT ×10.0 gave good diagnostic results for calcifications. Neither diet nor sex affected the appearance of the joints, whether calcified or normal. Because high-speed micro-CT is rapid and limits the animal’s radiation dose, it may be an effective technique for in vivo research.

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This is the first report describing neurogenic factor of Netrin-1 related to chondrogenesis or osteogenesis in a human cells. Netrin is a morphogenetic factor that induces a growth cone of an axial filament of the nervous system. However, the roles of Netrin in chondrogenesis or osteogenesis are not yet understood. We analyzed the relationship between Netrin and bone morphogenetic protein-2 (BMP-2) in chondrogenesis or osteogenesis, using a human chondrocyte-like cell line (USAC), which also retains multi-potency to differentiate into osteoblasts and adipocytes. Netrin-1 mRNA was decreased in USAC cells, though the expression was increased during osteogenic differentiation at the stage when osteocalcin mRNA were increased by BMP-2. Furthermore, inhibition of Netrin-1 gene increased Cbfa1 mRNA expression, and decreased Sox9 mRNA expression. We also found that Netrin-1was strongly expressed in immature chondrocytes of cartilage-like tissues that were formed in an exo vivo experiment with diffusion chambers. These findings indicate that Netrin-1 and BMP-2 regulates in the stage dependent process of mesenchymal cell differentiation to chondrocytes or osteoblasts.

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Dental caries often causes pulp inflammation once it reaches the dentine. In deep caries, there are many kinds of bacterial components, such as lipopolysaccharide (LPS), that induce the production of proinflammatory mediators, including tumor necrosis factor (TNF)-α. Inflammation in dental pulp tissue is associated with tissue degradation, and matrix metalloproteinases (MMPs) are believed to participate in this destruction. In the present study, we examined whether TNF-α and LPS affect the production of MMP-1 and MMP-3 in human dental pulp cells (HDPCs) of deciduous teeth utilizing RT-PCR and ELISA analyses. Exposure of HDPCs to TNF-α at 10 ng/ml for 6 h significantly increased the gene expression of MMP-1 and MMP-3. MMP-1 gene expression was slightly affected by exposure to LPS, while MMP-3 gene expression was significantly elevated by LPS at 0.1, 1 and 5 μg/ml. TNF-α at 10 ng/ml and LPS at 1 and 5 μg/ml potentiated the protein production of MMP-3, but not MMP-1, in HDPCs. The results of this study suggests that the mechanisms by which TNF-α and LPS induce MMP-3 expression may be important links in the pathogenesis of inflammatory diseases and reparative dentin formation in HDPCs of deciduous teeth.

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The objective of this study was to evaluate the capability of sonic vibration and continuous irrigation with various irrigant solutions to remove the smear layer formed by nickel-titanium (Ni-Ti) rotary instruments. Root canals were prepared in 56 single-rooted human mandibular premolars with no dental caries by using Ni-Ti rotary instruments. The teeth were divided into six experimental groups: control (Co) group, irrigated with sterile physiological saline only (8 teeth); SH group, irrigated with 5.25% sodium hypochlorite (NaOCl) solution (10 teeth); SC group, irrigated with 3% ethylene diamine tetraacetic acid (EDTA) solution (10 teeth); Co+Vi group, irrigated with sterile physiological saline along with sonic vibration (8 teeth); SH+Vi group, irrigated with 5.25% NaOCl solution along with sonic vibration (10 teeth); and SC+Vi group, irrigated with 3% EDTA solution along with sonic vibration (10 teeth).
The surface walls in the central portion of the coronal and apical halves of the root canals in experimental groups were examined with a scanning electron microscope (SEM), and the mean numbers of open dentinal tubules after root canal irrigation were calculated.
There was no statistically significant difference between the SH and SH+Vi groups, but cleaning capability improved significantly in the coronal area in the SC+Vi group compared with the coronal side in the SC group. In this study, we confirmed that continuous irrigation of the root canals using EDTA along with sonic vibration is effective in removing the smear layer formed by Ni-Ti rotary instruments.

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Biological apatite (BAp) crystallite c-axis alignment is known to one of the factor in mechanical function in bone. The purpose of this study was to investigate BAp crystallite alignment as a potential factor in the evaluation of bone strength in clinical practice by evaluating the relationship between BAp alignment and bone mineral density (BMD) using an experimental hemi-occlusion model in rabbit mandibular cortical bone.
A higher degree of BAp crystallite c-axis alignment was observed in the mesiodistal direction on the non-occlusion than on the occlusion side in the alveolar area, a tendency that was not seen in the base of the mandible. No significant differences were observed in BMD between the alveolar area and the base of the mandible or between the occlusion and non-occlusion sides. No correlation was observed between BAp crystallite alignment and BMD.
These results demonstrate that removal of occlusal force caused change in BAp crystallite alignment in the alveolar area in mandibular cortical bone. This indicates the importance of evaluating BAp crystallite alignment in addition to BMD in clinical practice. Moreover, clarification of BAp crystallite alignment in the jawbone would allow direction of occlusal load to be taken into account in orthodontic treatment involving tooth alignment.

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Signaling pathways have been shown to participate in the process of Retinoic acid (RA) - induced cleft palate (CP). In our current study, the signaling molecules of GSK-3β, Fzd3 and β-TrCP, which all relate with Wnt pathway, were screened from the palate tissues of the RA-induced CP in mice by the Gene-chip Technology. But, their expression pattern and level in palates during perinatal stages have not been known yet. In the studies, mRNA level of GSK-3β, Fzd3 and β-TrCP were detected by quantitative real-time PCR, and showed significant difference between the Embryonic day 18 (ED18) before birth and Postnatal day 0 (PD0) after birth, as well as between the RA-induced CP and wild type during the perinatal stage, respectively. And the localization pattern of GSK-3β, Fzd3 and β-TrCP proteins in palates was also characterized. Our data indicates that the Wnt signaling pathway may involve in the RA-induced cleft palate during peirnatal stage.

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To develop an improved surface conformation of titanium web (TW) scaffold, we examined the in vitro and in vivo biocompatibility of a thin hydroxyapatite (HA) deposited by pulsed laser ablation. Thin HA film was deposited on titanium discs using an pulsed laser operating at a repletion rate of 10 Hz and annealed by heating at 380 °C for 1 h. The presence of HA not only along the surface but also in the TW inner region was confirmed by the elementary mapping of calcium, phosphorous, and titanium. X-ray diffraction pattern showed that crystalline HA was present in the HA coating. Microscopic images after actin staining with rhodamine phalloidin revealed that the spread of clonal stromal cells was markedly greater on HA coating than on untreated TW. When infused with clonal stromal cells, the HA-coated TW could indeed generate bone formation in the backs of nude mice. However, the appearance of new bone was not enhanced by the HA coating, likely because air in the porous scaffold during cell loading reduces the cell-scaffold contact. Mild vacuum loading techniques might enable differences of osteo-differentiation between HA-coated TW and non-coated TW to emerge.

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Regeneration of periodontal ligament (PDL) is still a major issue in implant dentistry. In this study, we evaluated the effects of hydroxyapatite (HA) coating and occlusion on the regeneration of PDL around tooth-shaped titanium implants with root form. Three groups of tooth-shaped titanium implants, namely, non-HA-coated without occlusion (HA-/OCL-), HA-coated without occlusion (HA+/OCL-), and HA-coated with occlusion (HA+/OCL+), were immediately implanted into extracted tooth sockets with remaining PDL of rat molar model and the regeneration of PDL was examined histomorphometrically and histologically. Direct bony attachments were formed at the HA+/OCL- implant interface. In contrast, soft peri-implant tissue was distinctly seen between the HA+/OCL+ implant surface and surrounding alveolar bones. The shape of the load-time curve for the HA+/OCL+ group was similar to that for natural teeth. Peri-implant tissue of the HA+/OCL+ implants exhibited alkaline phosphatase with a distribution and activity similar to those of the PDL. Collagen fiber bundles were found functionally oriented in some regions of the peri-implant tissue. These findings indicate that the remaining PDL tissue around extracted sockets has the ability to regenerate bone and PDL-like tissues on HA-coated tooth-shaped implants. Occlusal loads to the HA-coated implants may induce regeneration of PDL-like tissue in the peri-implant tissue.

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Bone regeneration is critically regulated by various molecules. To understand the role of BMPs and some of their antagonists which regulate BMPs at extracellular level.we employed a mouse femur fracture model and to study their expressions during fracture healing. Real time PCR and In Situ Hybridization demonstrated that BMPs and their antagonists expressed during fracture healing, they peaked on different timing. In Vitro study by using different cell lines showed the same results. Our study further proved that BMPs regulate the expression of their inhibitors which make plausible the existence of a feedback regulatory mechanism. Skeletal homeostasis benefits from this delicate feedback regulatory mechanism.

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