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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.     

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.     

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。     

Prevalence of traumatic injuries to the permanent incisors in candidates for orthodontic treatment

Abstract  – The dental records made on presentation of 1367 consecutive patients (731 females and 636 males) for orthodontic treatment at a private orthodontic practice between 1998 and 2002 were examined for data relating to trauma to the permanent incisors. The results showed that 10.3% of these patients had suffered from dental trauma before the onset of orthodontic treatment. The highest prevalence of dental trauma was determined in the 11–15 years age group, corresponding to the dental developmental stage of the late mixed dentition. The most frequently affected teeth were the maxillary central incisors (79.6%), and the most common types of trauma were fracture of enamel–dentin without pulpal involvement (42.7%) and fracture of enamel (33.8%). Compared to patients with normal overjet and adequate lip coverage, the frequency of dental trauma was significantly higher in patients with increased overjet and adequate lip coverage ( P  = 0.028) or with increased overjet and inadequate lip coverage ( P  = 0.003). The results of the present study indicate that a significant percentage of candidates for orthodontic treatment, and especially those with increased overjet and inadequate lip coverage, suffer trauma to their permanent incisors before the onset of orthodontic treatment. It might also be concluded that preventive orthodontic treatment of such patients should be initiated and completed before the age of 11, i.e. in the early to middle mixed dentition.     

上颌阻生尖牙的临床诊断与治疗

目的：对阻生上颌尖牙的病因、临床检查、诊断及其相应的治疗进行了临床研究。方法：选取57例上颌尖牙阻生患者，通过病史询问、临床检查、X线片和模型测量的综合分析，从临床角度对阻生牙进行了诊断分类，采用不同的方法进行了矫治，并对矫治效果进行了评估。结果：采取适宜有效的治疗办法，均取得了满意的治疗效果，牙周膜愈合成功率达100％，活髓牙成功率达93．6％，牙龈形态良好者达89．4％。结论：尖牙阻生情况各异，治疗方法多样，根据临床分类选择合适的治疗方法，是矫治成功的关键。     

深覆盖患者正畸矫治后的面部软组织美学特征改变

目的:对两例生长发育高峰期后的骨性下颌后缩患者成功矫正深覆盖后的面部软组织改变进行研究。方法:患者矫治前后的头颅侧位X线片进行描图和重叠,分析软组织的变化。结果:软组织主要变化有:下面高增加,下唇明显前移,上唇后移,颏唇沟变浅,唇肌紧张度改善。结论:固定矫治器配合Forsus矫治器和II类间牵引使两例严重深覆盖患者的侧貌得到了明显改善。但矫正效果主要为牙颌-牙槽代偿,临床中需谨慎应用,注意病例选择。     

Begg正畸技术的临床应用（51例报告）

５１例应用Ｂｅｇｇ正畸技术矫治错畸形，各种类型的牙性及轻度骨性错畸形，均取得满意的效果。对牙轴唇倾并伴有深覆的安氏Ⅱ类错打开咬合、内收前牙的效果尤佳。