上下颌快速扩弓技术的应用——理论与实践

早在1860年Angle就提出可以通过打开腭中缝来扩大上颌骨。1961年Hass提出对于处在生长发育高峰期的青少年来说,可以通过上颌螺旋扩大器来打开腭中缝,扩大上颌骨;不同于上颌腭中缝的扩展,下颌正中联合的软骨在出生后1-1.5岁就与骨组织融合成一体,至青春发育期下颌已无法像腭中缝一样水平向展开,下颌非手术扩弓饱受争议。借鉴Bihelix、Schwarz、Crozat等下颌活动扩弓器的优缺点,改良制作了固定式钢网结构的下颌螺旋扩大器,将上颌Hyrax螺旋扩大器和改良的下颌螺旋扩大器同时应用于安氏各类错(牙合)畸形病例,均取得了令人满意的疗效。将螺旋扩大器应用于安氏Ⅰ类错(牙合)的主要目的是开辟间隙,解除中、重度拥挤;应用于安氏Ⅱ类错的主要目的是扩大上颌牙弓,解除上颌对下颌的阻挡,以利于下颌前移,纠正下颌后缩,上颌所开间隙用于直立唇倾的上前牙,以达到内收上前牙的效果,而下颌所开的间隙用于纠正下颌拥挤和整平过陡的Spee曲线;应用于安氏Ⅲ类错(牙合)的主要目的是快速扩大上颌腭中缝,配合面具前方牵引,刺激上颌基骨发育,纠正因前颌骨发育不足产生的前牙拥挤,扩大下颌牙弓,使上下牙弓宽度相匹配,纠正过陡的Spee曲线、同时内收下前牙。应用体会:1.在生长发育阶段,螺旋扩弓器可以有效地扩展上下颌牙弓,减少拔牙矫治。2.螺旋扩弓器主要用于非拔牙矫治,也适用于一些牙弓狭窄伴重度拥挤和牙槽前突需要拔牙的患者,可采取先扩弓后拔牙的方案。3.年龄和骨龄直接影响扩弓矫治的效果,同样年龄对男性患者可适当放宽适应症,而女性患者则需谨慎把握。4.将螺旋扩弓器与固定矫治联合使用,可获得所需支抗控制,取得更好的矫治效果。5.上下颌联合应用螺旋扩大器更有利于拥挤的解除和Spee曲线的整平,也有利于牙弓狭窄的解决。6.纠正不良习惯、适当延长矫治时间使肌肉充分适应增宽的牙槽骨从而获得良好的改建是保持扩弓效果稳定的基础,所追踪的完成后三到七年的病例,效果是稳定的。其后期的稳定性将在临床上继续观察。     

固定支架式扩弓器扩大上下颌牙弓初探

目的 探讨替牙(牙合)早期采用固定支架式扩弓器扩大上下颌牙弓矫治牙列拥挤的方法.方法 在1例9岁男童的上下颌同时黏结固定支架式螺旋扩弓器,上颌扩弓1个月,下颌扩弓2.5个月后,用"2×4"技术排齐拥挤的上下颌前牙,并用Hawley保持器保持.结果 上颌尖牙间宽度扩大5.4 mm,磨牙间宽度扩大9.0 mm;下颌尖牙间宽度扩大3.4 mm,磨牙间宽度扩大6.6 mm;上下牙列排列整齐,咬合关系良好.结论 对于基骨丰满、牙弓狭窄的轻度或边缘性中度牙列拥挤拟不拔牙患者,可在替牙(牙合)早期或中期试行上下颌同时扩弓治疗.     

安氏Ⅰ类牙列拥挤采用非拔牙快速扩弓矫治的疗效观察

目的:观察安氏Ⅰ类轻中度牙列拥挤患者采用非拔牙快速扩弓矫治的临床疗效。方法:对9例安氏Ⅰ类轻中度牙列拥挤病例,采用上颌快速扩弓配合上下固定矫治技术进行非拔牙正畸治疗,分别在T1(正畸治疗前)、T2(快速扩弓3个月后)和T3(正畸治疗结束进入固定保持期)3个时间点进行头影测量分析。结果:鼻外侧点间距、上颌基点间距、上颌第一磨牙间距和下颌第一磨牙间距在快速扩弓前后(T1-T2)以及正畸治疗前后(T1-T3)有显著性增加,其中上颌第一磨牙间距在T2-T3时间点也有显著性变化。全面高、前上面高、腭平面倾度、Y轴角在T1-T2以及T1-T3间有显著性增大。下颌平面角的变化在3个时间点之间均有显著性差异。结论:快速扩弓能引起上颌骨横向宽度显著增加,其变化包括骨性(上颌基骨)和牙性(上颌第一磨牙)两部分。快速扩弓虽然会导致上、下颌骨的向下旋转,但由于其变化量的绝对值不超过2mm或1°,因此可认为并无临床意义。快速扩弓不会引起上下颌骨矢状向的显著改变。     

用扩弓和多曲方丝弓技术矫治反(牙合)伴下颌偏斜畸形

目的 探讨扩弓和多曲方丝弓技术在安氏Ⅲ类错(牙合)伴下颌偏斜矫治中的作用机理。方法 选择安氏Ⅲ类错(牙合)伴下颌偏斜患者8例,均采用上颌扩弓技术矫治单侧上颌后牙反(牙合),多曲方丝弓技术不同程度地直立后牙,调整后牙在三维方向的位置,并解除前牙的反(牙合),调整下颌中线。结果 8例Ⅲ类错耠伴下颌偏斜患者均取得良好的矫治效果,矫治后磨牙为中性关系,前牙覆(牙合)覆盖正常。结论 轻度及中度安氏Ⅲ类错(牙合)伴下颌偏斜畸形患者通过上颌的扩弓及多曲方丝弓矫治技术可有效地矫正磨牙关系及下颌偏斜。     

快速扩弓和Damon技术非拔牙矫治牙列拥挤的比较研究

目的:分析比较快速扩弓(RPE)技术和Damon技术用于非拔牙矫治牙列拥挤的临床疗效.方法:选取19例骨性Ⅰ类中度牙列拥挤的青少年患者,进行非拔牙正畸治疗,其中9例采用上颌快速扩弓配合直丝弓矫治技术,10例采用Damon矫治技术.对2组患者正畸治疗前、后作模型和X线头影测量分析.使用SPSS15.0软件包作t检验,分析治疗前、后及2组间的差异.结果:治疗后,上、下颌尖牙间宽度RPE组分别增加了2.9mm和1.3mm,而Damon组没有显著变化.上、下颌后牙区牙弓宽度2组均有显著增加(P<0.05),其中,上颌第一前磨牙间宽度和下颌磨牙间宽度的增加,2组间无显著差异.上颌第一磨牙间宽度RPE组增加了5.3mm,显著大于Damon组的3.1mm;而下颌前磨牙间宽度的增加量Damon组为4.5mm,显著大于RPE组的1.5mm(P<0.05).治疗后,上、下磨牙均有显著颊向倾斜(P<0.05),Damon组和RPE组无显著差异.但上、下前磨牙的颊向倾斜量Damon组显著大于RPE组(P<0.05).RPE组上颌基骨宽距增加了2.1mm.显著大于Damon组(0.6mm)(P<0.05).h、下切牙突角U1-NA和IMPA的变化,Damon组分别为9.2°和7.5°,RPE组无显著改变,2组间有显著差异(P<0.05).结论:快速扩弓和Damon技术都能有效地通过增加牙弓宽度,成功达到非拔牙矫治中度牙列拥挤的目的.Damon技术主要以颊倾前磨牙和磨牙来增大后牙的牙弓宽度,同时伴有切牙唇向倾斜;快速扩弓能扩大上颌基骨和整个上颌牙弓宽度,并可维持前牙直立.     

成人非拥挤安氏Ⅱ1错(牙合)单颌拔牙矫治X线头影测量分析

目的:通过拔除上颌双侧第一前磨牙矫治成人非拥挤安氏Ⅱ1错(牙合),探讨治疗前后硬软组织的改变及意义.方法:选择非拥挤安氏Ⅱ1错(牙合)的成年患者11例,所有病例均拔除上颌双侧第一前磨牙,采用直丝弓矫治技术.将治疗前后X线头影测量结果,采用SPSS 10.0统计软件进行处理.结果:下颌骨发生了轻度后下旋转,上前牙及上唇发生了明显的内收,下前牙被压低,同时发生了轻度唇倾.结论:上颌单颌拔牙矫治成人非拥挤的安氏Ⅱ1错(牙合),改变主要发生在牙齿及牙槽骨水平,颌骨矫形作用不明显,此方法适用于牙性或轻度骨性的成人非拥挤Ⅱ1错(牙合).     

安氏Ⅱ类2分类错(牙合)的正畸治疗

目的 探讨扩弓和Ⅱ类牵引矫治青少年安氏Ⅱ类2分类错(牙合)的矫治时机及矫治原则.方法 青少年安氏Ⅱ类2分类错(牙合)患者10例,采用扩弓和牵引的方法矫治,比较矫治前后X线头影测量的变化.结果 矢状方向上,下颌骨位置(SNB)前移,下颌磨牙位置(L6-Ptm)前移明显;垂直方向上,上下颌后牙齿槽骨高度(U6-PP,L6-MP)增大,尤以L6-MP增大明显;上下切牙明显唇倾,U1-L1明显减小.结论 青少年Ⅱ类2分类错(牙合)非拔牙矫治患者采用扩弓和Ⅱ类牵引矫治可获得满意的疗效.     

前方牵引与快速扩弓联合矫治替牙期安氏Ⅲ类错(牙合)15例临床报告

目的观察联合应用前方牵引与快速扩弓矫治替牙期安氏Ⅲ类错(牙合)的颅颌面硬组织变化.方法选择30例8～13岁安氏Ⅲ类错(牙合)患者,随机分为两组,每组15例,治疗组使用前方牵引器与扩弓器治疗,另一组作为对照组.在治疗前后分别拍摄头颅侧位定位X线片,进行头影测量分析.结果治疗开始后6～12个月,治疗组Ⅲ类错(牙合)矫正,上颌骨前方生长明显增加,下颌骨向前方生长被抑制.上切牙牙轴唇倾,下切牙牙轴舌倾.结论在替牙期联合应用前方牵引器与扩弓器治疗安氏Ⅲ类错(牙合)能刺激上颌骨前移,抑制下颌骨的前方发育,可有效矫治安氏Ⅲ类错(牙合).     

安氏Ⅰ类边缘型牙列拥挤非拔牙快速扩弓矫治的临床疗效研究

目的研究安氏Ⅰ类边缘型牙列拥挤病例非拔牙快速扩弓矫治的牙弓参数变化,探讨其临床疗效.方法对9例安氏Ⅰ类边缘型牙列拥挤病例采用上颌快速扩弓配合上下固定矫治技术进行非拔牙正畸治疗,分别在T1(正畸治疗前)、T2(快速扩弓三个月后)和T3(正畸治疗结束进入固定保持期)三个时间点结合模型分析对牙弓参数进行分析.结果上颌第一磨牙、第一双尖牙和尖牙间宽度在T1、T2和T3相互之间均有显著性差异.下颌第一磨牙间宽度(T1-T2,T1-T3)和下颌尖牙间宽度(T1-T2)有显著性增加.上颌牙弓周径、上颌第一磨牙及第一双尖牙颊倾度有显著性增加(T1-T2),但有少量复发(T2-T3).下颌牙弓周径、下颌第一磨牙和第一双尖牙颊倾度随治疗均有显著性增加.结论快速扩弓能够通过改变上颌牙弓宽度增加其牙弓周径,下颌舌弓配合固定矫治也能显著增加下颌牙弓周径.因此可以较好地解决边缘型牙列拥挤中牙量/骨量不调问题,并有利于建立良好的咬合关系和疗效的稳定.     

成人非拥挤安氏Ⅱ~1错单颌拔牙矫治X线头影测量分析

目的:通过拔除上颌双侧第一前磨牙矫治成人非拥挤安氏Ⅱ1错,探讨治疗前后硬软组织的改变及意义。方法:选择非拥挤安氏Ⅱ1错的成年患者11例,所有病例均拔除上颌双侧第一前磨牙,采用直丝弓矫治技术。将治疗前后X线头影测量结果,采用SPSS10.0统计软件进行处理。结果:下颌骨发生了轻度后下旋转,上前牙及上唇发生了明显的内收,下前牙被压低,同时发生了轻度唇倾。结论:上颌单颌拔牙矫治成人非拥挤的安氏Ⅱ1错,改变主要发生在牙齿及牙槽骨水平,颌骨矫形作用不明显,此方法适用于牙性或轻度骨性的成人非拥挤Ⅱ1错。     

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.     

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.     

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。     

5种着色氧化锆陶瓷的细胞毒性评价

目的：对掺杂5种微量着色剂的氧化锆陶瓷的生物安全性进行初步评价.方法：采用四氮唑盐比色法（MTT）细胞毒性评价方法,用5种着色氧化锆陶瓷材料的浸提液体外培养L929小鼠成纤维细胞2 d、4 d、7 d,于倒置相差显微镜下观察细胞形态;用MTT检测各实验组和对照组的吸光度值（OD值）,计算各组细胞的相对增殖率,并按照6级毒性分类法对各实验组进行评级.结果：培养期细胞贴壁生长,细胞形态正常.随着培养天数增加细胞大量增殖,各实验组的毒性评级为0-1级.结论：添加5种微量着色剂的氧化锆陶瓷无细胞毒性,具备体内应用的生物安全基础.     

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。