微种植钉近中移动下颌第二磨牙关闭第一磨牙拔牙间隙

目的探讨微种植钉近中移动下颌第二磨牙关闭第一磨牙缺隙的正畸治疗效果。方法对5例第一磨牙缺失患者使用微种植钉近中移动下颌第二磨牙关闭其间隙。结果矫治后尖牙、磨牙中性关系,前牙覆盖、覆袷正常,后牙袷关系良好,下颌第一磨牙拔牙间隙关闭,第二磨牙近中移动量为11．7mm。疗程为18．5～31．0个月,平均为26．1个月。结论在下颌第一、第二双尖牙间采用微种植钉近中移动第二磨牙,能有效地关闭第一磨牙拔牙间隙。     

正畸治疗中磨牙的拔除和保留(三十八)——关闭下颌第一磨牙拔牙间隙后牙槽嵴高度及牙根吸收的随访研究

目的：通过对正畸关闭下颌第一磨牙拔牙间隙后牙槽嵴高度及牙根吸收情况的随访,探讨关闭磨牙间隙后牙周健康的长期稳定性。方法：共观察下颌第一磨牙拔牙间隙37处,下颌第二磨牙牙根74个。测量矫治结束及随访时的下颌第二磨牙近中牙槽嵴高度以及第二磨牙冠根比,将测量值进行配对t检验。结果：随访时下颁第二磨牙近中牙槽嵴高度以及冠根比与矫治结束时相比,均没有显著性差异。结论：采用拔除第一磨牙后的第二磨牙近中平移技术,关闭拔牙间隙的远期稳定性较好,有利于维持邻牙的牙周健康,可以充分发挥第二磨牙的咀嚼功能,以实现替代第一磨牙的作用。     

正畸治疗中磨牙的拔除和保留(三十八)——闭下颌第一磨牙拔牙间隙后牙槽嵴高度及牙根吸收的随访研究

目的:通过对正畸关闭下颌第一磨牙拔牙间隙后牙槽嵴高度及牙根吸收情况的随访,探讨关闭磨牙间隙后牙周健康的长期稳定性.方法:共观察下颌第一磨牙拔牙间隙37处,下颌第二磨牙牙根74个.测量矫治结束及随访时的下颌第二磨牙近中牙槽嵴高度以及第二磨牙冠根比,将测量值进行配对t检验.结果:随访时下颌第二磨牙近中牙槽嵴高度以及冠根比与矫治结束时相比,均没有显著性差异.结论:采用拔除第一磨牙后的第二磨牙近中平移技术,关闭拔牙间隙的远期稳定性较好,有利于维持邻牙的牙周健康,可以充分发挥第二磨牙的咀嚼功能,以实现替代第一磨牙的作用.     

正畸治疗中磨牙的拔除和保留（五十一）——关闭第一或第二磨牙拔牙间隙后相邻后牙根平行度的研究

目的：对临床中设计减数第一或第二磨牙矫治的病例进行调查,观察关闭间隙后相邻后牙根平行度情况。方法：选择病例41例,男10例,女31例,初诊年龄平均21岁,矫治结束时年龄平均23岁,所有病例均采用直丝弓矫治器矫治。分别对矫治前（T1）、矫治结束（T2）的拔牙间隙相邻后牙根平行度测量值进行分析。结果：减数第一磨牙矫治病例除下颌第二磨牙与第二前磨牙牙轴夹角及下颌第三磨牙与第二前磨牙牙轴夹角差别无显著性以外,其余测量项目均有显著性差异;减数第二磨牙矫治病例除上颌第一磨牙牙轴倾斜度及下颌第三磨牙与第一磨牙牙轴夹角无显著性差别外,其余测量项目均有显著性差异。说明第一或第二磨牙拔牙间隙关闭后上颌后牙不易达到根平行,下颌后牙容易达到根平行。结论：减数第一或第二磨牙的矫治方法可以实现下颌拔牙间隙相邻后牙的根平行,但对于上颌拔牙间隙两侧的牙齿很难实现根平行。原因主要是上颌后牙的牙根与上颌窦底的位置关系密切,对上颌后牙的牙根移动产生了阻碍。     

正畸治疗中磨牙的拔除和保留(十五)——正畸关闭陈旧性磨牙间隙前后牙槽嵴高度变化

目的：通过对正畸关闭陈旧性磨牙间隙前后牙槽嵴高度的对比,探讨关闭陈旧性磨牙间隙是否加重牙槽嵴吸收。方法：观察下颌第一磨牙陈旧性拔牙间隙29处。测量矫治前后该处牙槽嵴高度,将测量值进行配对t检验。结果：矫治后下颌第一磨牙缺牙处的牙槽嵴高度比矫治前增大,差异具有显著性。结论：采用拔除第一磨牙后的第二磨牙近中平移技术,不仅不会加重牙槽嵴的吸收,反而有助于维护该处牙周组织的健康。     

拔除病变第一磨牙后上、下颌第三磨牙正畸近移疗效比较

目的探讨拔除病变第一磨牙后上、下颌第三磨牙近移进行正畸治疗的效果。方法收集20例第一磨牙病变同时需要进行正畸治疗的患者,平均年龄18.6岁。根据患者口内情况将患者分为2组,每组10例。第一组上颌无明显拥挤,仅拔除病变的上颌第一磨牙,下颌拔牙或非拔牙矫治;第二组下颌无明显拥挤,仅拔除病变的下颌第一磨牙,上颌牙列拔牙或非拔牙治疗。全部病例均采用方丝弓矫治器,排齐整平牙列,关闭拔牙间隙,精细调整咬合关系。结果 20例患者都达到良好的矫治效果,双侧的磨牙、尖牙均达到良好的咬合关系。上颌第三磨牙前移平均8.8个月,平均近移7.94mm;下颌第三磨牙前移平均9.7个月,平均近移7.12mm。结论上、下颌由于存在骨质结构的差异,拔除无法保存的第一磨牙后,上颌第三磨牙近移比下颌磨牙较快。扶正簧的使用使倾斜的下颌磨牙得以直立。     

正畸关闭下颌第一恒磨牙缺失间隙的疗效观察

目的探讨正畸关闭下颌第一恒磨牙缺失间隙的疗效和矫治特点。方法选取16例下颌第一恒磨牙拔除超过1年以上的患者,与患者充分沟通后采用直丝弓矫治技术关闭缺牙间隙,观察疗效并分析矫治特点。结果16例患者均在19～26个月完成正畸治疗,所有患者第一恒磨牙缺失间隙关闭,前牙覆验覆盖正常,尖牙中性关系,磨牙为尖窝交错关系。软组织侧貌协调,患者对治疗效果满意。结论正畸法关闭第一恒磨牙缺失间隙可取得较好的临床治疗效果。     

Comparative study of the movement of upper and lower third molars after extraction of decayed first molars in orthodontics

目的 探讨拔除病变第一磨牙后上、下颌第三磨牙近移进行正畸治疗的效果.方法 收集20例第一磨牙病变同时需要进行正畸治疗的患者,平均年龄18.6岁.根据患者口内情况将患者分为2组,每组10例.第一组上颌无明显拥挤,仅拔除病变的上颌第一磨牙,下颌拔牙或非拔牙矫治;第二组下颌无明显拥挤,仅拔除病变的下颌第一磨牙,上颌牙列拔牙或非拔牙治疗.全部病例均采用方丝弓矫治器,排齐整平牙列,关闭拔牙间隙,精细调整咬合关系.结果 20例患者都达到良好的矫治效果,双侧的磨牙、尖牙均达到良好的咬合关系.上颌第三磨牙前移平均8.8个月,平均近移7.94mm;下颌第三磨牙前移平均9.7个月,平均近移7.12mm.结论 上、下颌由于存在骨质结构的差异,拔除无法保存的第一磨牙后,上颌第三磨牙近移比下颌磨牙较快.扶正簧的使用使倾斜的下颌磨牙得以直立.     

拔除下颌磨牙矫治安氏Ⅲ类错（牙合）关系的临床分析

目的：评价下颌第一磨牙拔除进行正畸治疗安氏Ⅲ类错（牙合）关系的疗效,第二磨牙向前移动代替第一磨牙的适应症,支抗控制方法等。方法：选择正畸门诊16例Ⅲ类错（牙合）关系并伴有下颌第一恒磨牙残冠、残根或牙冠大面积充填,在患者知情同意下拔除第一恒磨牙,使用直丝弓技术进行矫治。结果：所有16例病例均拔牙间隙完全关闭,无近中倾斜及舌倾现象。双侧磨牙Ⅰ类关系,面角减少,患者侧貌较直,取得较为满意的矫治疗效。结论：拔除下颌磨牙结合矫正技术可成功矫治恒牙期轻度骨性Ⅲ类错（牙合）畸形,并使患者软组织侧貌发生明显改变。     

正畸治疗中拔除下颌第一磨牙的临床疗效观察

目的探讨拔除下颌第一磨牙病例的正畸治疗方法。方法对28例下颌第一磨牙严重龋坏的错[牙合]畸形患者，拔除1—2颗下颌第一磨牙，选用0．56mm槽沟直丝弓矫治器进行治疗。结果矫治完成时间为13—39月，平均为27．6月。矫治后前牙覆盖、覆[牙合]正常；后牙[牙合]关系良好，所有拔牙间隙关闭，牙根平行，面部侧貌协调。结论在拔除下颌第一磨牙病例中，精心设计、力量合适和方法得当可有效控制下颌第二磨牙近中倾斜或近中舌向扭转。拔除严重龋坏的下颌第一磨牙，同时直立阻生的下颌第三磨牙是保持牙弓完整性的良好选择。     

Evidence of the validity of a model of determinants of quality of restorative dental care

A model describing the relationship between self-reported quality of restorative dentistry and dentist characteristics for 119 Montana general dentists is presented. The best predictors formed a significant model explaining 22% of the variance of the quality measure. Results are contrasted with a previous estimation of the model for 102 Washington general practitioners. Evidence for the external validity of the model is presented.     

Experimental evidence of formation of imines in the course of reduction of hydrazones

The reduction of hydrazones is generally suggested to proceed through a reductive cleavage of the nitrogen–nitrogen bond followed by a reduction of the carbon–nitrogen bond. This sequence of reduction processes is here supported for fluorenone (V) and benzophenone (VI) hydrazones as well as by a comparison of the reduction of fluorenone and benzophenone hydrazonium ions (I,III) with corresponding imines (II,IV). Another proof of the presence of imines as intermediates is the splitting of four-electron waves of hydrazones V and VI and hydrazonium ions I and VIII into two waves at pH < 2. This has been interpreted as due to differences in slopes dE_1/2/dpH and pK_a-values of protonated hydrazine derivatives on one side and corresponding imines on the other. In this pH-range imines formed in reductions of VI and VIII are reduced in a single two-electron wave, those of I and V in two one-electron steps. Fluorenone imine (II) is sufficiently stable to allow recording of time-independent current–voltage curves between pH 6 and 11. In this pH-range the imine (II) is reduced in two one-electron steps. Benzophenone imine (IV) has been found stable between pH 4.6 and 12. At pH 4.6–8 the reduction of the imine IV takes place in a single two-electron step, at pH 8–12 in two one-electron steps. Final proof of the initial cleavage of the N–N bond is presented by comparison with the reduction of nitrones.     

不同剂型玻璃离子水门汀溶解性比较研究

目的:研究、比较不同剂型玻璃离子水门汀的溶解性和表面微观形态改变,为临床使用提供依据.方法:将3M树脂加强型玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(水粉剂型)及GC玻璃离子水门汀(双糊剂型)分别在人工唾液中浸泡30 d,冷热循环15000次,烘干测重,比较前后质量变化,计算溶解率,并用扫描电镜观察表面微观改变.结果:不同剂型的玻璃离子水门汀溶解率由高到低分别为3M树脂加强型玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(双糊剂型).3种玻璃离子水门汀经浸泡溶解后,SEM扫描表面微观形态可观察到GE玻璃离子水门汀(双糊剂型)表面形态改变较少,其他2组玻璃离子水门汀表面微观改变较多.结论:双糊剂型玻璃离子水门汀理化性能及溶解率均低于传统水粉剂型,是未来临床修复治疗的的良好选择.     

Design of clinical trials of traditional therapies of periodontitis

The present paper on the design of clinical trials of periodontal therapy first addresses the issue of the etiology of periodontal disease. It is suggested that most if not all forms of destructive periodontal disease are caused by microorganisms and that there are different forms of disease with different microbial etiologies. The progressive nature of destructive periodontal disease is subsequently discussed and it is emphasized that, in a given patient, periodontal sites which show signs of inflammation and attachment loss may not over a period of several months and years show further sign of attachment loss. The present methods of assessing periodontal disease do not allow us to discriminate between potentially active and inactive sites in untreated patients. The significance and variability of indicators of periodontal disease such as bleeding on probing, probing pocket depth and probing attachment level measurements are discussed. The errors inherent in the various measurements are analyzed and suggestions are presented describing how alterations in any of the above parameters could be identified and presented in a clinical trial. Of concern for the statistical analysis of clinical data of periodontal disease is the definition of the "experimental unit". For a number of years, the "experimental unit" in periodontal trials was the patient. It is clear, however, that different sites within the same individual show different patterns of disease progression and lesion morphology and often respond differently to periodontal therapy. Statistical analyses must consequently be designed which recognize differences in site-to-site infection and lesion morphology within a common host. Until such analyses are available, the investigator should be wary of pooling data within the same individual, since such pooling may obscure meaningful alternatives which may take place in individual periodontal sites. Some goals of periodontal therapy are subsequently identified. 4 goals are discussed more in detail, namely: to establish conditions which will allow the patient to maintain a dentition without further breakdown of the periodontium; to reduce pocket depth to establish an anatomy in the dentogingival region which with proper maintainance care will prevent the re-establishment of the subgingival infection; to gain attachment as a result of treatment; to assess the effect of a certain chemotherapeutic agent on periodontal disease.     

Evaluation of efficacy of chemiluminescence for diagnosis of leukoplakia

ObjectiveLeukoplakia is the most common potentially malignant disorder preceding oral cancer. Chemiluminescence has been developed as an adjunct to conventional examination for the diagnosis of these potentially malignant disorders. This study was conducted to assess the efficacy of chemiluminescence in the diagnosis of leukoplakia and to compare the results with histopathological examination.Study designA total of 50 patients with leukoplakia were included from the outpatients attending the Department of Oral Medicine and Radiology, Dental Hospital, Bengaluru, Karnataka, India. These patients were subjected to conventional oral examination followed by chemiluminescent examination with Vizilite (Zila, Fort Collins, CO, USA) and biopsy for histopathological confirmation.ResultsThe sensitivity, specificity, positive predictive value, and negative predictive value of chemiluminescence were 93.75%, 55.56%, 78.95%, and 83.3%, respectively. The overall accuracy of chemiluminescence was 80%. A statistically significant association was observed between histopathology results and chemiluminescence results.ConclusionAlthough it is an easy, safe, minimal time consuming, and noninvasive technique, it has only adjunctive utility and it does not replace biopsy for the diagnosis of leukoplakia.     

颌骨动静脉畸形的栓塞治疗

目的：总结直接穿刺结合经血管内介入栓塞治疗颌骨动静脉静脉畸形的经验。方法：收治凳骨动静脉畸形患者6例,均进行了介入栓塞治疗。采用的栓塞材料为附凝血棉纤毛的螺圈,聚乙烯醇泡沫微粒和二氰基丙烯酸对丁酯。数字减影颈动脉造影在PHILIPSV300下完成。结果6例颌骨动静脉畸形患者中4,例急性出血得到了快速、有效控制,1例慢性渗血的右下 骨动静脉畸形患者,介入栓塞治疗,拔除松动的右下凳第一磨牙,有效地控制了出血,另1例伴局部软组织搏动性膨隆的上凳骨动静脉畸形患者,介入治疗后膨隆的搏动性得到明显改善,栓塞治疗后分别随访3－24个月,均未发现有口腔内渗血或出血。随访的X线片上,病灶区可见新骨形成。结论：局部穿刺结合经血管内介入栓塞治疗颌骨动静畸形是一种安全、有效的治疗方法。     

正畸患者切牙影像失真发生情况分析

目的研究正畸患者曲面体层片上的切牙影像失真发生情况，并分析其原因。 方法从中山大学附属口腔医院放射科影像数据库中选取500例正畸患者的曲面体层片和头影测量侧位片，所有曲面体层片均采用咬合杆投照，分别从切牙牙体影像放大、缩小、牙根变短、根尖模糊等评价指标分析上下颌切牙影像失真的发生情况，在头影测量侧位片上测量中切牙根尖-对颌切牙切缘的距离，探讨切牙影像失真发生的原因。采用SPSS 19.0统计软件对所得数据进行统计学检验。 结果500例患者中，切牙牙体影像正常者共417例，切牙牙体影像失真者共83例，影像失真发生率16.6%，其中切牙牙体影像放大17例、牙体影像缩小0例、牙根变短30例，牙根影像变短伴模糊36例。影像失真患者的根尖-切缘距离大于影像正常的患者，差异有统计学意义（F = 5 187.18，P = 0）；影像失真患者的覆盖值大于影像正常的患者，差异有统计学意义（F>477，P = 0）。 结论严重牙颌面畸形如反 、深覆盖是导致曲面体层片的切牙影像失真的主要原因之一。     

正常青年Monson球面半径的测量研究

目的测量正常青年Monson球面半径。方法选择60名(男30名,女30名)正常青年制取全口印模,应用立体摄影成像的原理与方法对Monson球面半径进行测量和统计学处理。结果Monson球面的半径平均为10.173 cm,大于理论值10.160 cm,差异有显著性(P<0.01);男、女性球面半径差异无显著性。结论本实验所得到的数据可作为全口义齿修复中记录颌位关系的一个参量。     

鼻测量法的进展

唇裂术后继发畸形是指唇裂修复术后,仍遗留或继发于手术操作和生长发育变化而表现出来的一类畸形[1]。包括唇畸形、鼻畸形和颌骨畸形。其修复较原发性唇裂修复更复杂,更灵活多变。而导致其修复复杂性的一个重要原因即是局部组织结构复杂变异和缺乏可靠的三维测量手段[2],鼻畸形