The indelible weight of place: Childhood neighborhood disadvantage,timing of exposure,and obesity across adulthood

I use 28 (1986–2014) years of restricted geocoded NLSY tract-level data and find positive associations between exposure to childhood neighborhood disadvantage and adult obesity and BMI among individuals growing up and entering adulthood during the rise of obesity in the United States. Sibling fixed effects and cousin fixed effects models partially address unobserved confounding nested in the nuclear as well as extended family. Furthermore, exposure to neighborhood disadvantage in adolescence is most salient, providing insight into when policy intervention may be most effective. Results are robust to alternative specifications for neighborhood disadvantage, ages of exposure, and to alternative sampling strategies.     

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??Objective    To investigate the effect of tooth movement at different time after the repair of alveolar bone defects. Methods    Defective alveolar bone model was established on one side in forty white rabbits??which were filled with bone meal and attached with Bio-Gide membrane as experiment sides. The other side was performed routine tooth extraction as control. Track the mandibular second molar in both sides respectively in 1 week??1 month??2 months and 3 months after operation. One month later??the distance between the mandibular second molar and third molar was measured with electronic vernier caliper in the experiment side and control side. The mandibular tissue was made paraffin section and hematoxylin eosin staining. Three views of the periodontal ligament in a third place of the mesial roots of the second molar was randomly chosen to count the total number of osteoclasts. Paired-t test analysis was made to evaluate the displacement of the mandibular second molar in experiment and control side??and to evaluate the number of osteoclasts in two side. Results    In Group 1w and Group 1 m??the displacement of the mandibular second molar in experiment group was smaller than that in the control side??P??0.05??. There was no statistical significance in Group 2 m and Group 3 m. The number of osteoclasts in the experiment side was less than the control group in Group 1 w and Group1 m??P??0.05??. No statistical significance in Group 2 m and Group 3 m was found. Conclusion    Orthodontic treatment can be performed two months after the repair of alveolar bone defects.     

活动与固定联合矫治在成人正畸中的应用

对成人正畸中活动与固定联合矫治的应用范围。优点及最新进展进行综述；提示只要进行合理设计，两种矫治方法能扬长避短，协同作用，获得良好效果。     

托槽弓丝组合对托槽-弓丝-结扎丝结构摩擦力的影响

目的　研究不同托槽 -弓丝组合对托槽 -弓丝 -结扎丝结构摩擦力的影响。　方法　选择四种槽沟为0 .0 2 2× 0 .0 2 8″的不锈钢方丝弓托槽 (三种国产 ,一种进口 ) ,与四种不锈钢丝 (0 .4 5 mm与 0 .5 0 mm的国产圆丝、0 .0 17× 0 .0 2 5″与 0 .0 19× 0 .0 2 5″的进口方丝 )分别组合分组 ,记录托槽与弓丝间滑动时的摩擦力 ,结扎压力保持在15 0 g。　结果　国产托槽与国产圆丝组合时的摩擦力大于与进口方丝组合时的摩擦力 ,进口托槽与国产圆丝组合时的摩擦力小于与进口方丝组合时的摩擦力。　结论　在特定结扎压力下 (如 15 0 g) ,如果材质相同 ,托槽与弓丝的表面粗糙度相差越大 ,摩擦力越小 ,粗糙度越接近 ,摩擦力越大。     

Adhesive fragment reattachment after orthodontic extrusion: a case report

Abstract –  In the treatment of crown fractures, adhesive fragment reattachment provides a good alternative to other restorative techniques, offering several advantages. The present paper reports a case in which the treatment of a cervical crown fracture was accomplished by reattaching the tooth fragment with a flowable resin composite. Orthodontic root extrusion was performed with a modified Hawley appliance prior to fragment reattachment. The clinical and radiographic results after 2.5 years were successful.     

口腔固定修复学临床前期实习中的问题与对策

本文总结了北京大学口腔医学院3届八年制口腔医学专业学生口腔固定修复学临床前期实习教学的经验,针对实习中出现的典型问题进行了分析,采取了相应的对策和方法,取得了良好的效果.     

The estrous cycle affects cocaine self-administration on a progressive ratio schedule in rats

Although it has been demonstrated that many of the behavioral responses to psychomotor stimulants are gender dependent and hormonally sensitive, few studies have examined the possibility that the estrous cycle interacts with drug reinforcement in laboratory animals. The present experiment assessed the effect of the estrous cycle on two aspects of cocaine self-administration behavior: the breaking point on a progressive ratio (PR) schedule and the rate of cocaine intake on a fixed ratio one (FR1) schedule. On the PR schedule, the first lever response produced a drug infusion. Subsequent response requirements escalated with each injection until the behavior extinguished. Breaking points were defined as the final ratio completed. On a FR1 schedule, the estrous cycle had no effect on the rate of drug intake. On a PR schedule, female rats reached higher breaking points during estrus than during other stages of the estrous cycle. Furthermore, female rats displayed higher breaking points than male rats. It appears that the estrous cycle influences an animal's motivation to self-administer cocaine.     

Social and psychological factors associated with adolescents'' self-acceptance of occlusal condition

Studies using plaster models of teeth and photographs simulating the full range of occlusal conditions have found high agreement between measures of adolescent social acceptability of these conditions and perceived need for orthodontic treatment. This study examined the association between adolescents' acceptability of their own occlusal condition, severity of malocclusion, and likelihood of undergoing orthodontic treatment. The factors predicting the acceptability of occlusal condition of 13-yr-olds, as assessed by the SASOC scale, were measurements of acceptability of general physical appearance, and the severity of occlusal condition. Variability in SASOC scores appeared to be independent of gender, socioeconomic status, and ethnicity. Gender, and severity of occlusal condition were important differences between subjects who had received, planned, or were undergoing orthodontic treatment, and those who had not. Neither SASOC scores nor perceived need for treatment accounted for a significant proportion of the variance between these groups. Although adolescents seeking orthodontic treatment had a greater severity of malocclusion than those not, little difference was observed between these groups in acceptance of occlusal condition.     

MEAW技术在固定矫治末期精细调整中的应用

目的：探讨MEAW技术在错He畸形固定矫治末期进行精细调整中的应用效果。方法：选取处于方丝弓固定矫治后期遗留局部小开He，上下颌牙齿尖窝交错关系未建立，中线未对齐等缺陷的病例7例，年龄14～24岁，平均年龄17．6岁，采用MEAW技术加颌间弹力牵引，进行咬合关系的精细调整。结果：经过MEAW技术3～6个月的调整，全部病例均达到预期的矫治效果，上下牙列建立了正常的覆He覆盖关系和良好的尖窝咬合关系。结论：对于固定矫治末期出现的小缺陷，通过MEAW技术加各种不同方向和力值的颌间弹力牵引，进行牙列的精细调整，能很好地恢复咬合关系，提高矫治效果。