Objective Liver is a common site of metastasis of gastric cancer and hitherto there has been no uniform treatment for liver metastasis of gastric cancer. This study was to investigate the clinical characteristics and prognostic factors of liver metastasis of gastric cancer in order to provide some evidence for the improvement of the diagnosis and treatment of the disease. Methods We ret-rospectively analyzed the clinical characteristics and survival data of 143 patients with liver metastasis of gastric cancer treated in our hospital between March 2007 and September 2012. We investigated the independent risk factors affecting the prognosis of the disease u-sing the Cox Regression Model. Results Seventy-five ( 52. 4%) of the 143 patients survived for 12 months, 41 ( 28. 7%) for 24 months, and 18 (12.6%) for 36 months, with a median survival time of 14 months. Univariate analysis revealed statistically significant differences in the survival time among the patients with different histological grades of primary gastric cancer, time of liver metastasis, types of metastatic liver cancer, extra-liver metastasis, and treatment methods ( P<0.05) . Multivariate Cox regression analysis showed the histological grade of gastric cancer to be low-or non-differentiation ( HR=2.67, 95% CI:1.51-4.72) and the type of liver meta-static cancer to be H2 ( HR=1.89, 95% CI:1.08-3.29) or H3 ( HR=2.13, 95% CI:1.32-3.44) , which were independent risk fac-tors affecting the prognosis of liver metastasis of gastric cancer, while palliative chemotherapy ( HR=0.55, 95% CI:0.32-0.95) was an independent protective factor of its prognosis. Conclusion Patients with liver metastasis from gastric cancer usually have a poor prognosis, especially those with histologically low-grade gastric cancer or type-H2 or -H3 liver metastatic cancer. The prognosis of thepatients undergoing palliative chemotherapy may have a better prognosis than those receiving best supportive care. A comprehensive therapy should be recommended to patients with liver metastasis from gastric cancer.

Objective: To understand the prevalence and influencing factors of Children s Dental Fear (CDF) among 12-15 year-old children in Shenzhen city, so as to provide a framework to alleviate CDF and promote oral health. Methods: Multi-stage stratified random sampling was used to select 5 509 children, aged 12-15 years, to participate in this study, which was carried out from October to November, 2018. The Children s Fear Survey Scheduling-Dental Subscale (CFSS-DS) and oral health examinations were conducted in Shenzhen. Results: The prevalence of dental fear in children aged 12, 13, 14, and 15 years in Shenzhen was 30.3%, 30.5%, 33.6%, and 26.9%, respectively(χ 2=11.97, P=0.01). The CFSS-DS scores were(29.86±13.23)(29.72±13.59)(31.23±14.47)(29.79±13.24), respectively(F=3.60, P=0.01). The CFSS-DS scores of male and female participants were (27.92±13.69) and (32.62±13.12)(t=-12.97, P<0.01), respectively, and the CDF prevalence rates were 23.8% and 38.8%, respectively(χ 2=159.29, P<0.01). Multivariate Logistic regression analysis showed that gender, brushing frequency, visiting experience, oral knowledge level, oral health attitude, oral health and general health status were correlated with CDF (P<0.05). Conclusion Attention should be paid to the prevalence of dental phobia among children aged 12-15 years in Shenzhen, and comprehensive intervention measures should be taken to improve children s oral health.

Objective: This epidemiology survey is intended to assess the periodontal health conditions of 12 to 15-year-old adolescents and the associated factors in Shenzhen. Methods: The study utilized a multistage stratified cluster method and recruited 5 509 middle school students aged 12 to 15. Gingival bleeding and calculus were conducted and a self-reported questionnaire was administered. Additional periodontal pocket depth and attachment loss examination were performed in the 15-year-age group. Periodontal conditions and the associated factors were analyzed by t-test, Chi-square method and Logistic regression. Results: The prevalence of gingival bleeding and calculus among adolescents was 43.95% and 44.25%, and the prevalence of periodontal pockets ≤3 mm was 0.57%. No periodontal pockets ≥6 mm or attachment loss ≥4 mm were detected. Gender, family income and frequency of teeth brushing were significantly associated with calculus detection (P＜0.05). The use of fluoride had an significant effect on gingival bleeding detection and calculus detection (χ 2=9.70，6.16，P＜0.05). Conclusion The periodontal health condition among 12-15 years old adolescents in Shenzhen is generally better than the national level. Adolescents living in high-economic districts and females had better periodontal health condition. The government can promote health education in schools and popularize the use of fluoride to improve the periodontal health condition among adolescents.

Objective:To investigate the clinical outcomes and complication of posterior surgery for Scheuermann kyphosis fusing to different distal fusion levels.Methods:From January 2012 to December 2017, a consecutive cohort of 34 patients who were treated with posterior spinal instrumented correction and satisfied the inclusion criteria were retrospectively reviewed, including 29 males and 5 females, aged 17.1±4.3 years (range, 12-30 years). All of the patients had a minimum follow-up of 2 years. According to the distal fusion level, patients were divided into 2 groups. Group sagittal stable vertebra (SSV) (22 cases) included patients whose lowest instrumented vertebra (LIV) was SSV; Group SSV-1 (12 cases) included patients who had a LIV one level above the SSV. Radiographic parameters including global kyphosis (GK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were measured in the standing radiographs before and after operation and at the latest follow up. Intraoperative and postoperative complications were recorded. The Scoliosis Research Society-22 questionnaire (SRS-22) were conducted at pre-operation and the final follow up to evaluate the clinical outcomes. The sagittal radiographic parameters and the incidence of distal junctional kyphosis (DJK) were compared between the two groups.Results:There were no significant differences in terms of age, sex, radiographic measurements and scores of SRS-22 between two groups preoperatively ( P>0.05). The correction rates of GK in the SSV group and the SSV-1 group were 42.8%±7.6% and 43.2%±8.4% ( t=0.151, P=0.881) respectively. While the correction rates loss were 1.2%±5.2% and 3.9%±7.2% ( t=0.767, P=0.449) at the latest follow up. No significant difference was observed in terms of other radiographic parameters ( P>0.05). During the postoperative follow up period, 3 patients (16.7%) in SSV group and 2 patients (13.6%) in SSV-1 group developed DJK. The incidence of DJK did not show any significant difference between two groups ( χ2=0.057, P=0.812). At the final follow-up, the function scores of SRS-22 in SSV-1 group (4.1±0.6) was significantly higher than SSV group (3.7±0.5) ( t=2.300, P=0.028) and there was no significant difference in the rest of the domain ( P>0.05). Conclusion:Compared with stopping at SSV, fusion to SSV-1 could achieve comparable curve correction with the preservation of more lumbar motility. Moreover, it would not increase the risk of DJK. As a result, we recommend selecting SSV-1 as the ideal LIV for SK patients.

Objective:To establish age- and gender-based normative values of sagittal spinal-pelvic alignment in Chinese adult population, and to investigate influence of age, gender and ethnicity on sagittal spinal-pelvic alignment in Chinese normal adults.Methods:A total of 786 asymptomatic Chinese adult volunteers aged between 20 and 89 years were prospectively recruited from different spine centers. The inclusion criteria were: 1) age between 20 to 89 years old; and 2) Oswestry disability index (ODI) scored lower than 20. The exclusion criteria were: 1) previous history of spinal, pelvic or lower limb pathologies that could affect the spine; 2) presence of recent and/or regular back pain; 3) previous surgeries on spine, pelvic and/or lower limb; and 4) pregnancy. Demographic characteristics of these subjects including age, gender, body weight and height were recorded. During the enrollment of volunteers, 16 groups were defined based on the age (20 s, 30 s, 40 s, 50 s, 60 s, 70 s and 80 s) and gender. Whole body biplanar standing EOS X-ray radiographs were acquired to evaluate the sagittal alignment. Spinal-pelvic parameters including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), thoracic kyphosis (T 5-T 12, TK), lumbar lordosis (L 1-S 1, LL), lower lumbar lordosis (L 4-S 1, LLL), global tilt (GT), T1 pelvic angle (TPA) and sagittal vertical axis (SVA) were measured. Values of PI-LL and lordosis distribution index (LLL/LL, LDI) were calculated. Radiographic measurements of 100 subjects were randomly selected to determine the intra- and inter-observer reliabilities using inter- and intra-class correlation coefficients (ICC). The spinal-pelvic parameters were compared among volunteers between different age and gender groups. The comparison was also made among various ethnic population. Results:The mean value was 23.7±7.1 kg/m 2 for BMI and 6.9%±2.5% (range, 0-18%) for ODI score. Each sagittal spinal-pelvic parameter was presented with mean value and standard deviationbased on age and gender. The ICCs of radiographic measurements ranged from 0.89 to 0.95, suggesting good to excellent intra- and inter-observer reliabilities. Significant differences were observed between males and females in multiple sagittal parameters (all P values <0.05). Compared to the male subjects, significantly higher values of PI (41.4° for male vs. 45.0° for female, P<0.001), PT (10.7° for male vs. 13.9° for female, P<0.001), PI-LL (-0.5° for male vs. 1.8° for female, P<0.001), and GT (10.9° for male vs. 13.5° for female, P<0.001) were documented in female subjects. Males had significantly higher values of LLL (28.6° for male vs. 26.6° for female, P<0.001) and LDI (0.68 for male vs. 0.63 for female, P<0.001). PI-LL, SVA, GT and TPA increased with aging from Group 40 s to Group 80 s, while LL, LLL and LDI decreased gradually, and TK decreased slowly with aging. Comparison of sagittal spinal-pelvic parameters between different ethnic subjects showed that Chinese adult population presented lower PI, SS, TK and LL as compared with American population; lower PI, SS and LL as compared with Japanese population. But the variation trend with aging tended to be consistent among different ethnic populations. Conclusion:Age- and gender-based normative values of sagittal spinal-pelvic alignment were established in asymptomatic Chinese adult population. Sagittal spinal-pelvic alignment varies with age and gender, and presented different compensation mechanism among different ethnic populations. Therefore, to achieve balanced sagittal alignment, age, gender and ethnicity should be take intoconsideration when planning spine correction surgery.

Objective:To evaluate the clinical outcomes and complications of second sacral alar-iliac (S 2AI) technique utilized in adult patients with neuromuscular scoliosis, and to evaluate the impact on patients' quality of life. Methods:All of 11 patients (6 males and 5 females) applying S 2AI technique from January 2014 to December 2016 were retrospectively reviewed. The average age of the patients was 39.6±12.7 years. Among them, 8 cases were poliomyelitis, 2 cases were spinal muscular atrophy and 1 case was muscular dystrophy. All of 11 patients underwent posterior spinal fusion and utilized S 2AI screws for pelvic fixation. All patients were taken anteroposterior and lateral radiographs of the entire spine. Cobb's angle, spinal pelvic obliquity (SPO), regional kyphosis (RK), sagittal vertical axis (SVA) were recorded at pre-operation, post-operation and last follow-up. The Scoliosis Research Society (SRS)-22 questionnaires and Oswestry disability index (ODI) were utilized to evaluate the patient-reported outcomes. All complications were also recorded. Repeated measurement analysis of variance, t-test or non-parametric test was used to analyzed the data, respectively. Results:The average follow-up period was 62.4±10.8 months. The pre-operative Cobb angle was 98.0°±24.0°, and the post-operative Cobb angle was 60.7°±20.8°, of which difference was significant ( Z=3.015, P=0.003). The correction rate of Cobb angles was 57.2%±17.7%. 1-year after operation, the Cobb angle was 62.8°±23.6°, no loss of correction was found ( Z=0.294, P=0.797). And at last follow-up, the Cobb angle was 61.6°±21.7°, the correction maintained well ( Z=0.603, P=0.594). The pre-operative, post-operative, 1-year post-operative and last follow-up spinal pelvic obliquity were 37.0°±11.8°, 21.5°±11.6°, 23.2°±10.1° and 21.1°±8.6°. The significant improvement was obtained ( Z=2.934, P=0.003) and no loss of correction was found ( Z=0.690, P=0.519; Z=0.000, P=1.000). The pre-operative, post-operative, 1-year post-operative and last follow-up regional kyphosis were 46.8°±23.6°, 18.6°±10.6°, 18.9°±11.4° and 19.5°±9.8°. The significant improvement was obtained postoperatively ( Z=4.364, P<0.001) and remained stable at the last follow-up ( Z=0.074, P=0.945; Z=0.271, P=0.838). When compared the pre- and post-operative sagittal vertical axis, no significant difference was detected. In these patients, one patient had rod breakage and underwent revision, one patient suffered deep infection, and recovered by debridement surgery, one patient suffered from severe pain in the lower back and relieved with conservative treatment. Conclusion:The S 2AI technique utilized in patients with neuromuscular scoliosis could obtain satisfying clinical outcomes and provides safe, durable fixation with low rates of complications.