拔除4个第一双尖牙正畸治疗满意病例Bolton指数的测量研究

目的　明确拔除 4个第一双尖牙对Bolton指数的影响以及对咬合关系的影响。方法　选取 4 3例拔除 4个第一双尖牙和 36例不拔牙治疗结果满意的病例 ,测量治疗后模型的牙齿宽度 ,计算比较其Bolton指数的差异 ;并计算不拔牙组在模拟拔除 4个第一双尖牙后的Bolton指数。结果　 1 拔除 4个第一双尖牙治疗满意的病例其全牙比小于不拔牙组 ,其差别具有显著统计学意义 (P <0 .0 0 1)。 2 不拔牙治疗满意的病例在模拟拔除 4个第一双尖牙后的全牙比亦小于未拔牙之前 (P <0 .0 0 1) ,与实际测量的拔牙组的全牙比没有统计意义上的差别 (P =0 .94 )。结论　拔除 4个第一双尖牙病例治疗后的全牙比小于不拔牙病例。拔牙后Bolton指数的变化对最终理想咬合关系影响不大     

拔除单个下颌切牙矫治安氏Ⅰ类错(牙合)满意病例Bolton指数分析

目的:研究在拔除单个下颌切牙矫治安氏Ⅰ类错(牙合)中Bolton指数的变化.方法:选取安氏Ⅰ类错(牙合)22例拔除单个下颌切牙治疗结束的满意病例,计算矫治前后记存模型的Bolton指数,并计算模拟拔出4个前磨牙矫治前后记存模型的Bolton指数.结果:①拔除单个下颌切牙治疗前Bolton指数前牙比为83.51±2.66,全牙比为92.74±2.09;矫治后的前牙比为69.39±2.41,全牙比为87.05±1.90,矫治前后的前牙比或全牙比均有显著性差异(P<0.01).(②模拟拔除4个前磨牙矫治前Bolton指数前牙比为83.51±2.66,全牙比为92.74±2.09;矫治后的前牙比为83.51±2.66,全牙比为91.77±2.76,矫治前后的前牙比无显著性差异(P>0.05),全牙比有非常显著性差异(P<0.01).③拔除下颌单个切牙矫治与模拟拔除4个前磨牙矫治Bolton指数前牙比或全牙比均有非常显著性差异(P<0.01).结论:Bolton指数较大的安氏Ⅰ类错(牙合),尤其前牙比过大者,选择拔除下颌单个切牙矫治是一种有效的设计方法.     

正畸拔除前磨牙对Bolton指数全牙比的影响

目的:探讨正畸模拟拔除前磨牙对Bolton指数全牙比的影响。方法:随机选择198例不同类型错畸形患者的记存模型,分别计算拔牙前和模拟4种模式拔牙后的Bolton指数全牙比。采用SPSS17.0软件包对数据进行统计学分析。结果:拔牙后的Bolton指数全牙比均有变小趋势,其中拔5/5、5/4模式降低更明显,与拔4/4、4/5模式相比有显著差异(P<0.01),但不同错类别间无显著差异(P>0.05)。结论:正畸医师在制订治疗方案时,应考虑到拔牙矫治会降低Bolton指数全牙比。     

拔除单个下颌切牙矫治安氏Ⅰ类错满意病例Bolton指数分析

目的：研究在拔除单个下颌切牙矫治安氏Ⅰ类错中Bolton指数的变化。方法：选取安氏Ⅰ类错22例拔除单个下颌切牙治疗结束的满意病例,计算矫治前后记存模型的Bolton指数,并计算模拟拔出4个前磨牙矫治前后记存模型的Bolton指数。结果：①拔除单个下颌切牙治疗前Bolton指数前牙比为83.51±2.66,全牙比为92.74±2.09;矫治后的前牙比为69.39±2.41,全牙比为87.05±1.90,矫治前后的前牙比或全牙比均有显著性差异（P〈0.01）。②模拟拔除4个前磨牙矫治前Bolton指数前牙比为83.51±2.66,全牙比为92.74±2.09;矫治后的前牙比为83.51±2.66,全牙比为91.77±2.76,矫治前后的前牙比无显著性差异（P〉0.05）,全牙比有非常显著性差异（P〈0.01）。③拔除下颌单个切牙矫治与模拟拔除4个前磨牙矫治Bolton指数前牙比或全牙比均有非常显著性差异（P〈0.01）。结论：Bolton指数较大的安氏Ⅰ类错,尤其前牙比过大者,选择拔除下颌单个切牙矫治是一种有效的设计方法。     

正畸拔牙后Bolton指数不调的多因素分析

目的　探讨安氏分类、术前前牙比、全牙比及不同拔牙模式对前磨牙拔除后Bolton指数的影响。方法　随机选择166副安氏错患者的模型,测量术前Bolton指数的前牙比、全牙比及拔牙后的Bolton指数值,以错安氏分类、术前前牙比、全牙比及拔牙模式建立Logistic回归模型,对拔牙后Bolton指数不调的发生进行多因素分析。结果　当术前前牙比、全牙比较小时,前磨牙拔除后Bolton指数趋于协调;而当术前前牙比、全牙比较大时, 前磨牙拔除后Bolton指数更趋于不调。不同的拔牙模式对Bolton指数的影响并不一致,当术前Bolton指数的前牙比、全牙比正常时,上下颌均拔除第一前磨牙,或上颌拔除第一前磨牙,下颌拔除第二前磨牙后,其Bolton指数值则明显高于正常。结论　矫治设计时,不仅要计算完整牙列Bolton指数的全牙比、前牙比,还要对所选择的拔牙模式后的Bolton指数进行分析,并多因素综合考虑,选择合适的拔牙模式。     

实际与模拟拔除前磨牙对Bolton指数的影响研究

目的:分析研究实际与模拟拔除前磨牙对Bolton指数及咬合的影响。方法:选择安氏Ⅰ类错牙合矫治后获得较理想咬合关系的牙牙合模型60幅(拔牙与非拔牙矫治各30副),测量其Bolton指数的前牙比、全牙比;同时对30例非拔牙矫治者进行4种模式的前磨牙模拟拔除,并计算其Bolton指数的全牙比并与实际拔牙组、非拔牙组进行比较分析。结果:实际拔牙组与非拔牙组Bolton指数的前牙比无显著性差异,全牙比拔牙组比非拔牙组小(P<0.001)。4种模拟的前磨牙拔除模式Bolton指数的全牙比间无显著性差异,与实际拔牙组的全牙比比较亦无显著性差异,但均小于非拔牙组的全牙比,其差异有显著性统计学意义(P<0.05)。结论:安氏Ⅰ类错牙合拔牙矫治较非拔牙矫治后Bolton指数的全牙比小,此变化是建立理想咬合所必需的。不同前磨牙拔除模式的Bolton指数全牙比相近,对咬合的影响相似。     

拔除上颌中切牙的正畸治疗分析

目的:探讨拔除上颌中切牙进行矫治的疗效和治疗特点。方法:选择拔除上颌中切牙进行矫治的患者9例,男4例、女5例,开始治疗年龄平均17.2岁。拔除双侧上颌中切牙和下颌2颗第一前磨牙者5例;拔除单侧上颌中切牙及对侧第一前磨牙和下颌2颗第一前磨牙者4例。进行治疗前后Bolton指数、X线头影测量和临床疗效分析。结果:所有患者均取得了良好的疗效。治疗前预测Bolton指数前牙比和全牙比分别为80.14%和91.31%;治疗后分别为78.68%和90.28%。X线头影测量分析治疗前后U1-NA(mm)、U1-NA、L1-NB(mm)、L1-NB、U1-SN、L1-MP、UL-E、LL-E的值减小(P<0.05)。结论:根据Bolton指数分析,进行个体化设计,拔除双侧上颌中切牙或单侧上颌中切牙及对侧第一前磨牙和下颌2颗第一前磨牙进行正畸治疗,可以获得良好的疗效。     

前磨牙拔除模式对不同错牙合畸形Bolton指数全牙比的影响

目的探讨前磨牙拔除模式对不同错牙合畸形Bolton指数全牙比的影响。方法选取180副牙性与骨性错牙合类型一致的患者模型,Ⅰ、Ⅱ、Ⅲ类每组60例,计算各组拔牙前和采用4种前磨牙拔除模式拔牙后的Bolton指数全牙比,以87%～89%为拔牙后Bolton指数全牙比参考值,对各组4种拔牙模式下Bolton指数全牙比的
异常率进行卡方检验。结果3组完整牙列Bolton指数全牙比差异有统计学意义（P=0.000）;Ⅰ、Ⅱ类组不同模式拔牙后Bolton指数全牙比异常率差异无统计学意义（P>0.05）,Ⅲ类组不同模式拔牙后异常率差异有统计学意义,拔除的异常率小于拔除（P=0.002）。结论从牙量协调的角度考虑,Ⅰ、Ⅱ类错牙合畸形采用4种拔牙模式均可,Ⅲ类错牙合畸形拔除的模式优于 。     

36例下切牙先天缺失正畸治疗的临床体会

目的探讨下切牙先天缺失的矫治设计。方法以伴有下切牙先天缺失的36例错畸形患者为研究对象，对下切牙缺失的部位、数目、错类型、矫治方法进行分析，并对缺失1颗下中切牙、拔除上颌2颗第一前磨牙和下颌1颗非缺牙侧第一前磨牙的病例及缺失2颗下中切牙、拔除上颌2颗第一前磨牙的病例的Bolton指数分析进行统计学检验。结果36例患者正畸治疗后均取得了较好的疗效。两组拔牙病例之间的Bolton指数全牙比无统计学差异（P>0.05），而前牙比和前牙不调量有统计学差异（P<0.01）。结论先天缺1颗下中切牙上下颌均需拔牙者，在下颌非缺牙侧选择拔1颗前磨牙比拔1颗中切牙对Bolton指数影响要小     

正畸拔牙模式对矫治后Bolton指数全牙比的影响

目的：探讨Bolton指数正常的安氏三种错（牙合）畸形病例经不同的拔牙模式治疗后Bolton指数全牙比的变化.方法：选取245例Bolton指数正常的安氏错（牙合）患者的模型,计算各组拔牙前和模拟4种模式拔牙后的Bolton指数全牙比,了解其变化趋势.结果：3种错（牙合）组拔牙后的Bolton指数全牙比均有变小的趋势;在安氏Ⅰ类错（牙合）与安氏Ⅲ类错（牙合）组中,除了二组与三组及四组与五组间Bolton指数全牙比的比较无统计学差异外,其余组间的比较均有统计学差异;安氏Ⅱ类错（牙合）组,不同拔牙模式的Bolton指数全牙比之间均有统计学差异.结论：BoIton指数正常的安氏不同错（牙合）畸形病例进行拔牙矫治时,前磨牙的拔牙模式会对拔牙后的Bohon指数全牙比产生影响.     

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.     

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.     

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.     

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.     

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.     

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。     

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。     

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。     

Electrodeposition of bilayers of dithiols

We report an electrochemical method to form a bilayer of dithiol. The cyclic voltammogram of the oxidative deposition of an aromatic dithiol on gold from an alkaline aqueous solution reveals two current peaks separated by more than 400 mV. The integrated charge of the oxidative current peak (B) at the most positive potential is twice that of the other oxidative current peak (A). These two oxidative current peaks were characterized by differential capacitance and electrochemical quartz crystal microbalance (EQCM) measurements. A decrease of the capacity by a factor of two, and an increase of the EQCM frequency change by a factor of two were observed when the potential was scanned from a value where only the first oxidative peak (A) is obtained, to a potential where both oxidative current peaks (A and B) are obtained. Infrared spectra show that the aromatic dithiols adsorb vertically at potentials corresponding to the current peak A and they become tilted for potentials corresponding to the current peak B. The simple relationships between the properties of the two oxidative current peaks are found to be compatible with a step-wise oxidative deposition of a bilayer of dithiol.