Objective To improve the level of CT in diagnosing LDH and to provide the proof for selecting method of clinical treatment in lumbar disc herniation (LDH). Methods 218 cases of LDH showed by CT and operative exploration were analysed retrospectively.Results The accurate rats of CT diagnosis of LDH were 95.4%. According to CT findings it may be divided into 5 types: Ⅰ was central type, Ⅱ was postero-lateral type, Ⅲ was forminal type, Ⅳ was extreme lateral type, was nucleus pulposus type. Conclusion CT plays an important role in diagnosis and selecting methods of clinical treatment of LDH; It is signficance to enhance the accurate rats of CT diagnosis and the effect of treatment by distinguish nucleus pulposus and fibrous scar tissue from CT finding of LDH.

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 changes and significance of human beta-defensin-2 (HBD-2) and LL-37 in the gingival crevicular fluid of patients with periodontitis and type 2 diabetes mellitus (T2DM). Methods: This study was conducted among 45- to 85-year-old patients in the Department of Stomatology and Internal Medicine of Shenzhen Center for Chronic Disease Control, including a healthy control group of 22 people, a systemically healthy control group of 19 people with periodontitis, a T2DM periodontal health group of 15 people, and a T2DM group of 21 people with periodontitis. The Florida periodontal probe was used for periodontal examination, and the clinical indexes, including probing depth (PD), clinical attachment level (CAL) and probing on bleeding (BOP), were recorded. The concentrations of HBD-2 and Ll-37 in gingival crevicular fluid were determined by ELISA. The differences in HBD-2, LL-37 and periodontal clinical indexes between the groups were compared, and correlation analysis was conducted. Results: The PD values in T2DM with the periodontitis group were higher than those of the systemically healthy controls with periodontitis group (P < 0.05); the levels of HBD-2 and LL-37 in gingival crevicular fluid in systemically healthy controls with periodontitis group were significantly higher than those in the healthy control group (P < 0.05), the level of HBD-2 in gingival crevicular fluid in systemically healthy controls with periodontitis group was significantly higher than that in T2DM with periodontitis group (P < 0.05); and the antimicrobial peptides HBD-2 and LL-37 in gingival crevicular fluid were significantly positively correlated with the PD and CAL in systemically healthy controls with periodontitis group (P < 0.05), and there was no significant correlation between the antimicrobial peptides HBD-2, LL-37 in gingival crevicular fluid and PD, CAL in T2DM with periodontitis group (P > 0.05). Conclusion The levels of antimicrobial peptides HBD-2 and LL-37 in gingival crevicular fluid of middle-aged and elderly patients with T2DM periodontitis were lower, and there was no significant correlation with PD and CAL in periodontal clinical indicators.