Objective: To intimately assess the internal stress distribution in ceramic veneer bonding layer. Methods:Six buccolingual cross section models of the incisor restored with IPS-Empress ceramic veneer were built with the MSC/NASTRAN software. 2D-finite element method was used to analyze the stress distribution regularity of the bonding layer on the models under different functional load. Results: Stress concentration areas of ceramic veneer bonding layer were regularly located on the incisal margin and cervical margin. Under the same condition, incisal load caused highest stresse on the adhesive layer. Following the load shift from incisal to gingival area, the stress was gradually decreased.When the functional load acted on the palate margin of the restoration, the compressive stress on the bonding layer was significantly increased. Different load angle generated stress change in the bonding layer. The shear stress on adhesive layer increased following the horizontal load angle increasing close to the debonding level. Among the different incisal reduction designs there was no significant Von Mises stress variation under the same load condition. However, when the incisal edge was reduced by more than 4 mm, the tensile stresses in the bonding layer greatly increased. Conclusion: Restoration margin should be kept away from the tooth contact area, be exposed to minimal occlusion contact. The functional load should be induced to follow the tooth long axis. Edge to edge occlusion should be avoided. When incisal areas need to be altered, the incisal overlap or butt margin design will not cause any stress problem in the bonding layer. When restoring the incisal defect for more than 4 mm, the bonding agents must be selected carefully.

Objective:To make a within-subject comparison of masticatory function and pattern between complete denture(CD)and implant-supported overdneture(IOD).Methods: Three edentulous patients volunteered to take part in this test.Each of the patients was rehabilitated with lower CD first and lower IOD later,and with the upper denture of CD.The masticatory efficiency,mandibular movement trace and the surface electromyograph (EMG) of masseters,anterior temporlis and posterior temporlis were measured 3 month after the use of each set of the dentures.Results: With IOD,each patient increased masticatory efficiency,especially when chewing almond.The regulation of chewing cycle,centralization of end traces and occlusal slides of mandibular movement were significantly improved.The electricactivity of masseters,anterior and posterior temporlis all enhanced by means of increasing contract intensity and the rhythm of the mastication was more regular.The muscle activity pattern in two cases transformed from instable to stable,while that of the another patient changed from masseter preponderant pattern to temporlis preponderant pattern.Conclusion: Patients with IOD have a heigher masticatory efficiency,more regular mandibular movement pattern,more effective masticatory muscle contractive pattern and masticatory muscle coordinative pattern than those with CD.

Objective:To analyze the features of the connective tissue associated interstitial lung disease (CTD-ILD) by high resolution computed tomography (HRCT).Methods:A total of 127 patients with CTD-ILD,who were diagnosed by clinic laboratory examination and pathology in Xiangya Hospital of Central South University form September 2013 to September 2015,were enrolled for this study.Their lung features of HRCT imaging were retrospectively analyzed.Results:The classifications for 127 patients were as follows:36 cases of rheumatoid arthritis (28.3%),34 cases of dermatomyositis and polymyositis (26.8%),31 cases of systemic sclerosis (24.4%),18 cases of Sj(o)gren syndrome (14.2%),7 cases of mixed connective tissue disease (5.5%),and 1 cases of systemic lupus erythematosus (0.8%).According to the features of HRCT imaging,the patients were divided as follows:77 cases (60.6%) ofnonspecific interstitial pneumonia (NSIP),46 cases (36.2%) of usual interstitial pneumonia (UIP),2 cases (1.6%) of lymphocytic interstitial pneumonia (LIP),1 case (0.8%) of cryptogenic interstitial pneumonia (COP),and 1 case (0.8%) of acute interstitial pneumonia (AIP).The HRCT findings for 36 cases of rheumatoid arthritis associated interstitial lung disease were UIP (24 cases,66.7%) and NSIP (12 cases,33.3%);the HRCT findings for 34 cases of dermatomyositis and polymyositis associated interstitial lung disease were NSIP (32 cases,94.1%),UIP (1 case,2.9%) and COP (1 case,2.9%);the HRCT findings for 31 cases of systemic sclerosis associated interstitial lung disease were NSIP (21 cases,67.8%),UIP.(9 cases,29%),LIP(1 case,3.2%);the HRCT findings for 18 cases of Sj(o)gren syndrome associated interstitial lung disease were NSIP (9 cases,50.0%),UIP (8 cases,44.4%),LIP (1 case,5.6%);the HRCT findings for 7 cases of mixed connective tissue disease associated interstitial lung disease were UIP (4 cases,57.1%),NSIP (3 cases,42.9%).SLE-ILD was rare,with only 1 case of AIP.Conclusion:Different types of CTD-ILD patients display relatively unique manifestation of HRCT.

Objective:To classify the interforaminal arch form of edentulous mandibles by measuring the anterior-posterior distance (A-P distance) of implants planned to be inserted in All-on-4 protocol using conebeam computed tomography (CBCT) data, and to investigate the influence of the arch form on the All-on-4 distally tilted implants.Methods: Seventy-four CBCT images of edentulous mandibles were collected, including 35 males and 39 females respectively.All-on-4implant supported fixed prostheses were designed for these patients based on the CBCT data.The A-P distance was measured in the plane which crossed bilateral mental foramens and was parallel to the occlusal plane.The interforaminal arch form of edentulous mandibles were classified according to the A-P distance.The radian of the jaw arch 7.5 mm mesially to the mental foramen was measured bilaterally, and its correlation with the A-P distance was studied.Results: The average A-P distance of implant supported fixed prostheses planned in the interforaminal region was (8.5±1.5) mm (minimum 4.5 mm, maximum 11.8 mm).In the study, 12.2% of the subjects'' mandibles were classified as square arch form with A-P distances ≤7 mm, 54.0% were classified as ovoid with A-P distances >7 mm and ≤9 mm, 33.8% were classified as tapered with A-P distances >9 mm.Bilaterally, 148 results of the radian of the jaw arch 7.5 mm mesially to the mental foramen were obtained, and the average radian was 15.9°±5.5° (minimum 5.6°, maximum 35.2°).The radian and the A-P distance showed a negative correlation with statistical significance.Conclusion: In this research, the ovoid arch form was the most common type in edentulous mandibles, followed by tapered arch form.The square arch form showed the lowest percentage.As the arch form went squarer, the A-P distance became shorter, the radian of the jaw arch mesially to the mental foramen went greater, and the bone width that distally tilted implants need became bigger.The interforaminal arch form of the edentulous mandible should be analyzed before an implant supported fixed restoration is designed in the interforaminal region.The angle of inclination of distal implants should be reasonable.The bone width of the distal implant site must be adequate.The square arch form contributes negatively to the structure of implant supported fixed prostheses with distal cantilever design.

This paper is aimed to develop a computerized three dimensional system for displaying and analyzing mandibular helical axis pathways. Mandibular movements were recorded using a six-degrees-of-freedom ultrasonic jaw movement recording device. The three-dimensional digital models of the midface and the mandible were reconstructed and segmented from CT skull images. The digital models were then transformed to the coordinate system of mandibular motion data by using an optical measuring system. The system was programmed on the base of the Visualization ToolKit and Open Scene Graphics Library. According to the motion data, transformation matrices were calculated to simulate mandibular movements. Meanwhile, mandibular helical axis pathways were calculated and displayed three dimensionally by means of an eigenvalues method. The following parameters of mandibular helical axis were calculated: the rotation around instantaneous helical axis, the translation along it, its spatial orientation, its position and distance relative to any special reference point. These parameters could be exported to describe comprehensively the whole mandiblular movements. It could be concluded that our system would contribute to the study of mandiblular helical axis pathways.
Humans ; Imaging, Three-Dimensional ; Mandible ; Models, Anatomic ; Movement ; Rotation

ObjectiveTo investigate the diagnostic value of interferon gamma release assays (IGRAs) in children with tuberculous meningitis.MethodsThe prospective case-control study was applied. From January 2012 to March 2013, 32 children diagnosed with tuberculous meningitis (TBM group) and 30 children diagnosed with non-tuberculous meningitis (non-TBM group) were recruited. The positive rates of the interferon gamma release assays (IGRAs), tuberculin skin test (TST), mycobacterium tuberculosis antibody test (TB-IgG), cerebrospinal lfuid of mycobacterium tuberculosis DNA test (TB-DNA), and the sensitivity, speciifcity, negative and positive predictive value of all these tests were compared between TBM group and non-TBM group.Results The positive rate of IGRAs, TST, TB-IgG, and TB-DNA was 87.50%, 56.25%, 46.88% and 34.38%respectively in TBM group, and 6.67%, 23.33%, 20% and 0% respectively in non-TBM group. The differences were statistically signiifcant (P<0.05). The sensitivity of IGRAs, TST, TB-IgG, and TB-DNA was 87.5%, 56.25%, 6.88% and 34.38% respectively. The speciifcity of IGRAs, TST, TB-IgG, and TB-DNA was 93.33%, 76.67%, 80.00% and 100% respectively. The differences of sensitivity and speciifcity were statistically signiifcant (P<0.05). The sensitivity of IGRAs was higher than that of other tests (P<0.017). The positive predictive value of IGRAs, TST, TB-IgG, and TB-DNA was 93.33%, 72%, 71.43% and 100% respec-tively. The negative predictive value was 87.50%, 62.16%, 58.54% and 58.82% respectively.Conclusions IGRAs, TST, TB-IgG, and TB-DNA are valuable in the diagnosis of tuberculous meningitis. IGRAs has a relatively higher sensitivity and speciifcity.

Objective: To search for a simple and rapid cell culture method for human gingival epithelial cells with a high success rate. Methods:Culture medium containing serum has been proved to have the ability of accelerating the early adhesion of human gingival tissue blocks, and the migration of gingival epithelial cells from the rim of the blocks. By means of this, we introduced the serum containing DMEM to the cell culture medium within the first 7-10 days, and changed with serum free cell culture medium to accelerate the mitosis, proliferation, and migration of the gingival epithelial cells, which had moved out from the tissue blocks. Using the combined method, cells were identified by the method of morphology, immunohistochemistry and analysis of the cell growth curve, as well as SEM. Compared study of the effects on the cell growth between combined method and serum containing DMEM or serum free EpiLife culture method was conducted. Results: Cells were harvested within 17-22 days. Primary culture success rate was 90.6%. Cultured cells were slabstone shaped. Immunohistochemistry analysis of keratin antibody showed a positive result. The cells had stronger ability of migration and proliferation in the serum free cell culture medium compared with that in the serum medium. Conclusion: This method can culture the gingival epithelium cells conveniently with accelerated speed.

Objective:To evaluate the clinical efficacy and safety of SpyGlass-guided laser lithotripsy for large common bile duct (CBD) stones with diameter>2 cm.Methods:From August 2015 to August 2018, a total of 157 patients with large CBD stones at the First Affiliated Hospital of Shandong First Medical University who met the inclusion criteria were randomly divided into SpyGlass group ( n=78, underwent SpyGlass-guided laser lithotripsy) and laparoscopic common bile duct exploration (LCBDE) group ( n=79, underwent LCBDE) by using random numbers. Non-inferiority test was used for rates of one-time stone removal and total stone removal, and the non-inferiority margin was set to 10%. The transform rate, incidence of short-term complications, hospital stay, and quality of life (assessed by the gastrointestinal quality of life index) were compared between the two groups. Results:The total success rates of stone clearance were 92.3% (72/78) and 96.2% (76/79) in the SpyGlass group and LCBDE group, respectively ( P=0.023), with valid non-inferiority hypothesis. The one-time stone removal rates were 83.3% (65/78) and 96.2% (76/79), respectively ( P=0.124), with invalid non-inferiority hypothesis. There were no significant differences in the incidence of transform [7.7% (6/78) VS 3.8% (3/79), P=0.294] or short-term complications [5.1% (4/78) VS 10.1% (8/79), P=0.246] between the two groups. Compared with the LCBDE group, the SpyGlass group had a shorter hospital stay (5.65±0.94 d VS 8.84±1.54 d, P=0.001) and higher scores of gastrointestinal quality of life index (1 month after operation: 99.85±4.36 VS 91.51±5.47, P=0.001; 3 months after operation: 131.24±3.32 VS 112.32±7.77, P=0.001). Conclusion:For large CBD stones, the efficacy of SpyGlass-guided laser lithotripsy is not inferior to LCBDE, and it is less invasive. In the future, SpyGlass-guided laser lithotripsy could be an important option for the treatment of large CBD stones.

OBJECTIVETo investigate the variation in movement traces of different condylar reference points.

METHODSIn 30 healthy subjects, mandibular movements were recorded during protrusion and open-closing of the jaw. The kinematic center and terminal hinge axis point of the condyle were used as reference points.

RESULTSThe kinematic center was located anteriorly and superiorly with respect to the terminal hinge axis point. The trace distance of the kinematic center was longer than that of the terminal hinge axis point of the condyle during opening. In contrast to differences in trace distances of the left and right condylar terminal hinge axis points, no such left-right differences were found for the kinematic centers. The ratio between the distance of opening trace and the distance of protrusion trace of the kinematic center was above 1.5.

CONCLUSIONSIn comparison to the terminal hinge axis, the kinematic center shows fewer variations in the movement traces.

Objective To investigate the prevalence and awareness rate of adult diabetes mellitus and the risk factors in Liaoning Anshan. Methods A cross-sectional population survey was performed among residents in Liaoning Anshan and 2 500 subjects participated. Subjects whose fasting plasma glucose ≥ 5.6 mmol/L were confirmed by oral glucose tolerance test (OGTT). Results The standardized prevalence of adult diabetes mellitus over the age of 20 in Liaoning Anshan was 8.2%, and the standardized prevalence of pre-diabetes mellitus was 14.8%. The prevalence of diabetes mellitus increased with age (P<0.05). The awareness rate of diabetes mellitus in Liaoning Anshan was 52.3%(125/239), and the awareness rate of pre-diabetes mellitus was 8.7%(35/402). Logistic regression indicated that age, family history of diabetes, overweight or obesity, waist circumference, hypertriacylglycerolemia was the risk factors (P<0.05), while regular exercise was protective factor (P<0.05). Conclusions The current prevalence of diabetes mellitus and pre-diabetes mellitus in Liaoning Anshan is higher, and the awareness rate is lower.