Objective To evaluate the indications and effectiveness of lower incisor extraction in orthodontics.Methods Twenty-three adult patients with lower incisor extraction were included in the study.The cases consisted of 14 female and 9 male patients with an average age of 23.2 years at the start.One single lower incisor was extracted in 17 patients and the other tow upper premolars were extracted in 6 patients.Cephalometric and casts analyses were carried out.Results Total treatment time was 13-23 months.All extraction space was closed after the treatment.All patients achieved satisfactory treatment results,with normal overbite and overjet and stable occlusal relationship.There were no significant changes before and after treatment on cephalometric analysis.The intercanine width was reduced by from pretreatment to posttreatment [(26.89--2.89) mm vs (23.92-t-1.54) mm (P＜0.05)].Conclusions The intercanine width is reduced after lower incisor extraction.In order to achieve satisfactory clinical effect,we should carefully select cases and pay attention to the corresponding techniques and methods.

Objective To discuss the clinical application of internal stent in tracheal stenosis.Methods 101 cases of large airway stenosis were treated with the self-expanding Ni-Ti alloy stents through oral cavity(41 cases)or nasal cavity(60 cases) under X-ray guided.Results The placement of Ni-Ti stents in all cases was successful one time.Of 64 cases,tracheal stents were introduced,bronchial stents,tracheal and bronchial stents were set up in 64,20 and 17 cases respectively.Shortness of breath was relieved obviously after process.Conclusion The placement of Ni-Ti stent is an effective and safe method for the treatment of large airway stenosis.

Objective To verify the significance the Atlas Fixation (AF) for thoracolumbar vertebrae.Methods 61 patients with fracture of thoracolumbar spine were operated by AF internal fixation. And to evaluate the effectiveness of the AF by X ray and CT scans. Results The patients of Frankel's B～D were improved by 1～2 scroe after operation. There were no iatrogenic nerve root injury and broken screws. There no earlier period infection. 2 had peri-screws abscess after 6 months by operation. Conclusion Compared with other spinal posterior internal fixation, AF has better results in effectiveness and simplification.

Objective To evaluate incisor root resorption of adults with skeletal classⅢmalocclusion through three-dimensional reconstruction of cone beam computed tomography (CBCT) image using interacting medical imaging control sys?tem (Mimics) and then offer guidance for labially tilted angle control in orthodontic treatment and distance of bone moving in surgery. Methods Adults of skeletal class Ⅲ malocclusion (n=30) who underwent orthodontic-orthognathic combination treatment were included in this study. CBCT images were then reconstructed three-dimensionally using Mimics 10.01. Each incisor were separated at cementum-enamel junction as crown and root. Labially tilted angle and root volumes of each inci?sor were measured before and after operations. At last, the correlativity between root resorption and labially tilted angle was calculated through statistic analysis. Results The decrement of upper, lower and front incisors’root volumes upon treat?ment is statistically significant. However, there is no statistically significant difference of incisor ’s root volumes among eight incisors nor between different gender. There is linear correlation between root volumes and labially tilted angle when the lat?ter changes 7° or more when they followed the fomular =-21.416+5.618X. Conclusion For adults with skeletal classⅢmalocclusion, orthodontic treatment before orthognathic surgery decrease incisor root volumes when labially tilted angle changes 7° or more.

Objective To investigate the change and correlation between hard-tissue and soft-tissue in patients with class III malocclusion after premolar extraction treatment. Methods Thirty-four adult patients with skeletal classⅢmalocclusion who met the including criteria were included in this retrospective study. The lateral cephalographs were traced and analysed before and after the treatment. Results After orthodontic treatment,the values of long axis of upper incisors and S-N angle (U1-SN) and long axis of lower incisors-mandibular plane (L1-MP) were decreased, and the angle of man-dibular plane (MP-FH) was increased (P<0.01). The SL line was used as a reference, the protrusion of upper incisor (UI-SL) and upper lips (UL-SL) was decreased, and the protrusion of lower incisors (LI-SL) and lower lips (LL-SL) was also de-creased after orthodontic treatment (P<0.05 or P<0.01). There was no significant difference in the relevant measurements of chin. The retraction of upper incisor (△UL-SL) was the only measurement that was positively correlated with upper lip re-traction (△UI-SL). The retraction of upper incisor (△UI-SL) and lower incisor (△LI-SL) were positively correlated with the lower lip retraction (△LL-SL). There was a positive correlation between△UI-SL and△LL-SL. Conclusion The soft-tissue profile improved significantly after four premolars extraction. The change of soft-tissue profile was moderate correlated with hard-tissue.

Objective: To examine the effects of ? carotene and ? tocopherol on LDL oxidation by monocyte derived macrophages from SD rats (in DMEM medium). [WT5FZ]Methods: Macrophages were incubated with LDL in DMEM in which freshly dissoved VE (40,100,200 ?mol/L) and ?C (0.5,1.0,2.0 ?mol/L) had been added. After incubating for 24 h, the mediums were centrifuged to determine TBARS and lipofusin and dienes. [WT5FZ]Results: Supplementation of ? tocopherol significantly decreased TBARS, lipofusin and conjugated dienes production and electrophoretic mobility. Supplementation of ? carotene at 0.5 ?mol/L significantly decreased TBARS, lipofusin and conjugated dienes production and electrophoretic mobility, but other levels showed no effect. Increasing ? carotene concentration to 2.0 ?mol/L in the system increased the lipofusin production compared with control group. ? tocopherol at 200 ?mol/L and ? carotene at 0.5 ?mol/L were the most effective in all dose groups. [WT5FZ]Conclusion: Cell mediated oxidation of LDL can be regulated by antioxidants such as ? tocopherol and ? carotene.

Objective:To investigate the effect of VE and VC at different dietary levels on plasma lipid metabolism, lipid peroxidation and mRNA of scavenger receptor (SR). Methods:Male SD rats, fed purified and cholesterol enriched diet, were divided into five groups(12 rats per group). The experimental groups were fed diets with either VE(150 or 350 mg/kg diet) or VC (1 000 or 2 000 mg/kg diet) respectively. The experiment lasted 56 days. Results:Compared with control group, both VE and low dosage VC could significantly lower the concentrations of total cholesterol(TC), low density lipoprotein cholesterol(LDL C), atherogenic index (AI),Apo B and lipoperoxide, and increase the levels of high density lipoprotein cholesterol (HDL C), and inhibit the expression of SR mRNA..Conclusion:VE and VC can decrease the concentrations of serum TC and LDL C,restrain formation of Ox LDL and expression of SR mRNA.

The equipment development for emergency medical aid station of the Armed Police applies modern medical science and technology as well as management system.Based on the functional necessity,it accords with the theory of wartime health service support and draws on the experience of anti-terrorism struggle in foreign countries.It realizes serialization,modularizaion and motorization.This paper mainly introduces the development background,systematical structure and functional characteristics of the equipment for the emergency medical aid station.

Objective To determine the incidence and risk factors of retinopathy of prematurity (ROP) in preterm infants.Methods Fundus examinations were performed by RetCam Ⅱ ophthalmoscopy on 2185 premature infants (birth weight ≤ 2000 g or gestational age≤34 weeks)admitted into the neonatal intensive care unit of Beijing Bayi Children's Hospital from January 1st 2009 to December 31st 2010.According to the results,all infants were divided into ROP group and nonRO P group.Two-sample t test and Logistic regression analysis were used to investigate the risk factors of ROP.Results Among 2185 premature infants,287 (13.1 ％) cases were diagnosed with RO P.According to International Classification of RO P,34 cases (11.9 ％) were in zone Ⅰ,147 cases (51.2％) in zone Ⅱ,and 106 cases(36.9％) in zone Ⅲ.And there were 117 cases (40.8％) with stage 1 lesion,142 cases (49.5％) with stage 2 lesion,28 cases (9.7％) with stage 3 lesion,and no stage 4 or 5 lesion was identified.Thirty-six cases (12.5 ％) were accompanied by additional diseases.Logistic analysis showed that small gestational age (OR=0.859,95％CI:0.770-0.958,P=0.006),low birth weight (OR=0.729,95％CI:0.6340.838,P=0.000),long duration of oxygen supplement (OR=2.221,95％CI:1.904-2.592,P=0.000),assistant ventilation (OR=3.104,95％CI:2.0964.956,P=0.000),apnea (OR=1.767,95％CI:1.103 2.831,P=0.018) and=anemia (OR=2.242,95％CI:1.641-3.604,P=0.000) were independent risk factors of ROP.Conclusions The incidence of ROP in premature infants is high.Small gestational age and low birth weight,long duration of oxygen supplement,assistant ventilation,apnea and anemia are risk factors of ROP.Preventive measures should be taken against these factors.

ObjectiveTo compare the neonatal outcomes between infants of assisted conception (AC) and natural conception (NC). Methods A prospective case-control study was conducted.Eligible mothers were invited to this study at 28 weeks of gestation and were followed up to delivery.All newborns were examined by pediatricians right after birth.Data including gestational age,birth weight,admission to neonatal intensive care unit (NICU),and presence of any major malformation were collected.Statistical analysis was performed with SPSS 13.0.Difference between two groups was compared by x2 test. ResultsSix hundred and seventy-three newborns were enrolled into this study,including 325 in AC group and 348 in NC group.There were no differences between the demographic characteristics of the two groups,including maternal age,parents' education,family income and proportion of primipara (P＞0.05).The incidences of twins (32.62％ vs 3.45％,x2 =98.88),preterm birth (30.46％ vs 7.76％,x2=56.92),low birth weight infant (32.31％ vs 8.91％,x2 =57.07)and admission to neonatal intensive care unit (27.38％ vs 8.91％,x2 =39.16) and proportion of cesarean birth (62.77％ vs 21.55％,x2=117.64) in AC group were significantly higher than in NC group (all P＜0.01),except for the incidence of birth defect (4.62％ vs 2.59％,x2=2.01,P＞ 0.05).However,no significant differences was found in the above items when only singletons were compared between the two groups (P＞0.05),except for the cesarean section rate (61.18％ vs 22.03％,x2 =100.93,P＜0.01).There were no difference in any of the above neonatal outcomes when different assisted reproductive technologies applied were compared(in vitro fertilization-embryo transfer,intracytoplasmic sperm injection and frozen embryo transfer) (P＞0.05).Conclusions Neonatal outcome after assisted conception is a bit worse than natural conception,which might mainly due to the large proportion of multiple pregnancy after assisted conception.In order to improve neonatal outcome after assisted conception,the number of embryos transferred should be limited.