[Imaging characteristic of Stafne bone cavity：a retrospective study based on cone-beam CT].

PURPOSE: To guide clinical decision-making more efficiently via collecting and analyzing the imaging data of patients with Stafne bone cavity(SBC). METHODS: Six patients with SBC were retrospectively reviewed in Stomatological Hospital of Shandong University. By assessing cone-beam CT (CBCT) data, age, sex, complaint, cavity location, diameter at three dimension, maximal cross-sectional area of multi-planar reconstruction planes, content gray scale, morphological classification and its relationship with mandibular canal were recorded respectively. RESULTS: A total of 6 cases were inadvertently found on CBCT, with no symptoms. The locations of SBC were between mandibular molar region and mandibular angle, inferior border of mandible and mandibular canal, mostly at lingual side. Three were on the left and three were on the right. The bone cavity was elliptic and its long axis was consistent with the long axis of the mandible, with an average long axis diameter of (16.43±4.54) mm, horizontal axis diameter of (6.91±1.48) mm, vertical axis diameter of (10.24±2.10) mm. According to the multi-planar reconstruction planes readings, the maximal cross-sectional area of the bone cavity was (91.93±25.52) mm2, the maximal coronal area was (57.26±23.23) mm2, and the maximal sagittal area was (127.80±51.22) mm2. In view of the classification in the relationship between SBC marginal line and buccal cortical bone, there were 2 cases of type I cavity, 3 cases of type II cavity and 1 case of type III cavity. The connection between the bone cavity and the surrounding anatomical structure was classified into 3 conditions: covering penetration, adjacency and separation on the basis of the relative position between the cavity boundary with the mandibular inferior margin and the mandibular canal in sagittal plane. In addition, the content type could be primarily identified depending on estimation of corrected grey scale in the center of bone cavity. CONCLUSIONS: CBCT can make an intuitive and clear diagnosis of Stafne bone cavity, which brings great significance into the early clinical decision-making, thus not only avoiding unnecessary surgery, reducing the waste of additional medical resources, but also decreasing the physical and mental trauma of patients.

The association between chronic periodontitis and oral Helicobacter pylori: A meta-analysis.

BACKGROUND: Epidemiological studies have shown that gastrointestinal Helicobacter pylori (H. pylori) infection is the main cause of chronic gastritis, but the relation between oral H. pylori and chronic periodontitis (CP) remains uncertain. A meta-analysis of published papers was performed to elucidate the correlation between oral H. pylori and CP. METHOD: To perform this meta-analysis, we searched papers published from 2000 to 2018 on PubMed, OVID, Springer Link, Chinese National Knowledge Infrastructure (CNKI) and Chinese Biology Medicine search engines. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for the correlation between H. pylori and CP were estimated. Heterogeneity, publication bias and subgroup analyses were also conducted. RESULTS: A total of 918 papers on oral H. pylori and CP were collected, and 11 papers were in accordance with the inclusion criteria. Oral H. pylori was suggested to be correlated with CP. The results indicated that a H. pylori-positive state significantly increased the risk of CP 3.42 times (OR = 3.42; 95% CI = 2.71-4.31). A diagnostic test using polymerase chain reaction (PCR) showed a higher prevalence of H. pylori (OR = 3.70; 95% CI = 2.66-5.14) than did that using the rapid urease test (RUT) (OR = 3.13; 95% CI = 2.26-4.34). CONCLUSIONS: This paper demonstrated that CP was potentially correlated with oral H. pylori in adults and that oral H. pylori may be a possible risk factor for CP.

[Effect of CORM-2 on atherosclerosis in experimental periodontitis of rats].

PURPOSE: To evaluate the effect of CORM-2 (carbon monoxide releasing molecule-2) on atherosclerosis in experimental periodontitis of rats. METHODS: Forty Wistar rats were divided into four groups randomly. Rats in control group did not receive any procedure; animals in the carbon monoxide group (CO group) and the chronic periodontitis group (CP group) were induced experimental periodontitis and treated with CORM-2 (10mg/kg per day), or normal saline solution (NaCl 0.9%), respectively; animals in the solvent group (DMSO group) received dimethylsulfoxide solution (DMSO 0.05%) only. Blood samples were collected after 1, 3, 7, 14 and 28 days from all animals for analysis of C react protein (CRP), oxidized low density lipoprotein (ox-LDL), soluble vascular cell adhesion molecule-1, (sVCAM-1) and interleukin-10 (IL-10) by enzyme-linked immunosorbent assay (ELISA). Rats were sacrificed after 28 days. Lipid deposition was checked by means of oil red staining in the descending aorta. Changes in alveolar bone levels were measured and periodontal tissues were histopathologically examined to assess the infiltration of inflammatory cells. SPSS17.0 software package was used to analyse the experimental data. RESULTS: The serum levels of CRP, ox-LDL and sVCAM-1 in CP group were significantly higher than that in CO and the other two groups (P<0.05). The level of IL-10 in CP group was significantly lower (P<0.05). Lipid deposition in the descending aorta was observed in CP group. The alveolar bone loss and the ratio of presence of inflammatory cell infiltration (ICI) in CP group were significantly higher compared with CO groups (P<0.05). CONCLUSIONS: This study demonstrated that CORM-2 can not only reduce the inflammatory response in periodontal tissues in rats with experimental periodontitis, but also inhibit atherosclerosis-associated cytokines and lipid deposition in descending aorta, which suggests a favorable potential in treatment of periodontitis and atherosclerosis.

A modification of a direct technique for the fabrication of posts and using wax pattern.

This new direct technique for the fabrication of posts and cores using a wax pattern is easy to manipulate. It requires no special armamentarium and is appropriate for various situations. It provides the advantage of a direct technique and ensures the post pattern's precise fit. It also avoids the disadvantage of other direct techniques, the limitation of the direction of the cores by the placement of the broaches, the pins, or the prefabricated dowels.

[Effect of different nanophase hydroxyapatite particles on osteoblasts metabolism].

PURPOSE: To compare two different structural nanophase hydroxyapatite(HA) particles on the proliferation activity and functions of osteoblasts. METHODS: Primary culture of osteoblasts from rat calvaria was established and then cultured on the coatings of different size of nano particles (groupI 20-40nm,group II 70-100nm), the HA coatings without nano-particles was used as control group. Proliferation activity, protein content and synthesis of alkaline phosphatase(ALP) by osteoblasts were examined by MTT assay, coomassic brilliant blue method and PNPP test, and statistical significance was assessed by multiple comparison (q test, SNK) in one-way analysis of variance (ANOVA) with SPSS10.0 software package. RESULTS: Osteoblasts grew well on HA coatings. MTT assay demonstrated that there was significant difference between group I and group II at 6th day and 8th day (P<0.05).At first half stage(5th day and 10th day) ALP activity test showed no significant difference between group I and groupII (P>0.05) and as the culture going on(15th day and 20th day), there was significant difference between the two groups (P<0.05). Coomassic brilliant blue method showed that there was significant difference between group I and group II from 5th day to 20th day (P<0.05). CONCLUSION: The diameter of nano-particles on the HA coatings could influence the proliferation activity and functions of the osteoblasts. The nano-particles of similar size with HA crystal in vivo showed better cytocompatibility.

[Experimental study on the proliferation of postirradiated osteoblast transfected with Ad-hBMP-2].

PURPOSE: To investigate the exact relationship at which Ad-hBMP-2 can exert its effects on postirradiated proliferation of osteoblasts in rats. METHODS: The osteoblasts used were isolated from the calvariae of neonatal (one-day-old) Wistar rats by sequential enzymatic digestion. The third passage of the cells were irradiated with X-ray at the doses of 0, 100, 300, 500,700 and 900 cGy. The medium was changed immediately and the Ad-hBMP-2 were added. After 6 days of culture the cells were examined and measured for proliferation ability by MTT test, and the data were analyzed with SPSS13.0 software package for Student's t test. RESULTS: After irradiation, the proliferation ability of osteoblasts was inhibited and the effects were more remarkable as the dose increased. Ad-hBMP-2 could counteract the inhibitory effects when irradiation dose was lower (100 cGy),and partially when the dose was higher (500 cGy). There was significant difference between the cells transfected with Ad-hBMP-2 and the cells of control groups (P<0.05). When the dose was over 700 cGy, the damages of the cells seemed irreversible and there was no significant difference between the two groups (P>0.05). CONCLUSION: Ad-hBMP-2 could increase the proliferation ability of postirradiation osteoblasts, and the effect depends on the dose of radiation.

Combined effects of soluble vascular endothelial growth factor receptor FLT-1 gene therapy and cisplatin chemotherapy in human tongue carcinoma xenografts.

The aim of the present study was to assess the anti-tumor effect of a defective adenovirus that expresses soluble vascular endothelial growth factor (VEGF) receptor FLT-1 (AdsFLT-1) in combination with cisplatin (cis-diamminedichloroplatinum, DDP) on human tongue carcinoma Tca8113 cell xenografts that had been pre-established in nude mice. In vitro, Tca8113 cells secreted soluble FLT-1 (sFLT-1) after infection with AdsFLT-1, and the conditioned medium from AdsFLT-1-treated Tca8113 cells seemed to inhibit VEGF-induced proliferation of human umbilical vein endothelial cells. The combined effects of sFLT-1 gene therapy and DDP chemotherapy was then studied in well-established Tca8113 xenografts. The concentration of sFLT-1 in serum reached a peak 8 days after intratumoral injection of AdsFLT-1. In these tumors, AdsFLT-1 intratumoral injections had only a small effect. Interestingly, when the cells were also exposed to DDP chemotherapy, significantly higher (P<0.05), and possibly synergistic, anti-tumoral effects were observed that were highly correlated to a marked reduction in intratumoral vascularization and an increase in tumor-cell apoptosis. Together, these data emphasize the potential of combining an anti-angiogenic gene therapy strategy with a destructive approach directed against the tumor cells to fight human tongue carcinoma.

[Experimental study of mandibular periosteal distraction in rabbits].

OBJECTIVE: To investigate a novel technique for new bone formation--periosteal distraction osteogenesis. METHODS: A custom made periosteal distraction device was fixed to bilateral surface of the mandible in three rabbits. Periosteal distraction was performed on the left side of the mandible, the right side of the mandible served as the control. The animals were sacrificed at the end of distraction process. All the specimens were X-rayed and histologically examinated. RESULTS: All three animals survived with no obvious complications. Both in mass specimens and X-rays, there showed new bone formation on the distracted side of the mandible. In histological examinations, there was osteoblast-like cell infiltration and bone tissue formation in the distracted area. CONCLUSION: Periosteal distraction osteogenesis can provide a novel technique for the repair of bone defects.

[Repair of mandibular central fissures in rabbits with hBMP-2 gene modified tissue engineered bone].

PURPOSE: To evaluate the effectiveness of the tissue engineered bone substitute loaded with periosteal-derived osteoblasts (POBs) transfected by adenovirus mediated human bone morphogenetic protein-2 gene (Ad-hBMP-2) in the repair of rabbit mandibular central fissures. METHODS: 45 rabbits with the soft tissue in the mandibular central fissures removed were randomly divided into 5 groups, group I: Ad-hBMP-2 transfected POBs/bioglass group (n=10); group II: adenovirus mediated enhanced green fluorescent protein (Ad-EGFP) gene transfected POBs/bioglass group (n=10); group III: untransfected POBs/bioglass group (n=10); group IV: single bioglass group (n=10); group V: control group (n=5). The above bone substitutes were implanted in the rabbit mandibular central fissures respectively except group V. The samples were studied by gross, X-ray, histomorphology, histomorphometrical analysis and biomechanics after 2, 4, 8, 12 weeks respectively. One-way ANOVA was used for statistical analysis. RESULTS: In gross view, the rabbit mandibular central fissures in group I were replaced by new bone including cortical bone from the 4th week. X-ray examination showed that the higher bone density was found in the rabbit mandibular central fissures of group I 4 to 8 weeks after implantation. Histomorphometrical analysis showed much more new bony callus in group I than in other groups (P<0.01). The maximal anti-bending load and bending rigidity of the implanted bone substitute of group I were significantly higher than those of group II, III and IV (P<0.01). CONCLUSION: The tissue engineered bone substitute loaded with POBs transfected by human BMP-2 gene could get the best result in the repair of rabbit mandibular central fissures, therefore, it is likely to be used in the repair of alveolar clefts.

[Evaluation of peri-implant augmentation with collected bone].

PURPOSE: To determine the amount of bone harvested from dental implant osteotomies with aspeo 12000 bone collector, to characterize the nature of the debris, and to evaluate the histological viability and clinical effect of peri-implant augmentation with immediate implantation of collected bone. METHODS: From May 2004 to Oct 2005, 15 recruited patients without peri-implant imperfections underwent 18 ITI implants installation. During the implant bed preparation, 18 samples of bone were collected using the instrument and an analysis of variance was used to determine if there were statistical differences between female versus male, maxilla versus mandible, anterior versus posterior alveolar bone. After decalcification, the material from each sample was fixed in paraffin wax and stained with haematoxylin and eosin, all sections were examined by optical microscope and the proportion of bone was established histomorphometrically. During the time, 12 defects occurred in 11 patients when 16 dental implants were installed, and all the defects were augmented with collected bone debris simultaneously. RESULTS: About 93% volume of 'wet' bone could be obtained from one dental implant osteotomy, and there were no statistical differences between female and male, maxilla and mandible, anterior and posterior alveolar bone. Histological observation showed that all samples contained bone and coagulum, the mean bone proportion was 94.2%. 3 to 6 months after surgery, the defects were successfully augmented, and during the secondary operation, bone growth was found over the defects. CONCLUSION: The use of bone collectors is a good method for obtaining material to fill small bone imperfections in dental implantation.

[Surgical treatment of obstructive sleep apnea hypopnea syndrome after velopharyngeal ring ligation procedure].

PURPOSE: To evaluate the effect of removal of ligation thread combined adenoidectomy in the treatment of obstructive sleep apnea hypopnea syndrome (OSAHS) after velopharyngeal ring ligation procedure (VRLP). METHODS: The upper airway was examined with dynamic fiberoptic pharyngoscope in six patients with cleft palate who were diagnosed as OSAHS by polysomnography(PSG) after VRLP. All the patients underwent removal of ligation thread and adenoidectomy. Three months after operation, they were recalled back and were examined with polysomnography and dynamic fiberoptic pharyngoscope. The preoperative and postoperative PSG data were analysed with t test and chi-square test to determine the statistical differences. RESULTS: In patients with OSAHS after VRLP, a ring scar was observed on the upper airway at the soft palate level and a remarkable narrow nasopharyngeal meatus was found mainly because of adenoidal hypertrophy. After removal of ligation thread and adenoidectomy, no velopharyngeal incompetence was found, the upper airway morphology was smooth, respiration disorder during sleeping was completely disappeared and sleep architecture became normal. There were significant differences between preoperative and postoperative PSG data. CONCLUSION: Removal of ligation thread combined adenoidectomy was an effective treatment for OSAHS after VRLP.

[A serious complication-obstructive sleep apnea hypopnea syndrome after velopharyngeal ring ligation procedure: report of 6 cases].

PURPOSE: To discuss the occurrence and characteristics of obstructive sleep apnea hypopnea syndrome (OSAHS) after velopharyngeal ring ligation procedure (VRLP). METHODS: Seven hundred and eight cleft palate patients underwent velopharyngeal ring ligation procedure from 1997 to 2003. Nine cases were found having some suspicious symptoms of OSAHS after operation and 6 of them were confirmed as OSAHS by polysomnography. Six VRLP patients without OSAHS as controls were examined with polysomnography. Chi-square test and t test were used to determine the statistical differences between the groups. RESULTS: Six cases of 708 patients met the criterion of severe OSAHS and the incidence of OSAHS after VRLP in children below 12 years was 1.8%. Compared with controls, more arousals and longer awakening were found in OSAHS group, the ratio of III and IV phase of NREM and REM in total sleep was significantly decreased (P<0.01). CONCLUSION: OSAHS was likely to occur in VRLP patients below 12 years. Many feature of this kind of OSAHS were different from the ordinary pediatric OSAHS. It showed that OSAHS after VRLP was characterized by more apneas, less partial upper airway obstruction and associated with distinguished staged desaturation.