锥形束CT在诊治牙体根尖周病中的应用进展

锥形束CT（CBCT）具有高空间分辨率、相对较低的辐射剂量,从三维角度显示复杂的口腔颌面部影像,获得无失真的颌面部骨及牙体组织信息,是口腔颌面部疾病的重要影像检查工具。本文就CBCT在诊治牙体根尖周病中的应用进展进行综述。     

X线平片加大垂直角投照法诊断上颌前磨牙双根作用的评价

目的:应用锥形束CT(cone-beam computed tomography,CBCT)探讨X线平片加大垂直角投照法鉴别上颌前磨牙双根的可行性。方法:选取上颌牙需做CT检查的患者31例,上颌前磨牙患牙共109颗。在CT三维重建影像上测量患牙牙根的实际径值及在水平角38.5°和垂直角为45°时的牙根投影值并对比分析。采用SPSS12.0软件包对数据进行t检验。结果:上颌前磨牙根尖实际宽度(3.74±0.22)mm与投影宽度(3.69±0.16)mm接近,无显著差异(P>0.05);牙根中1/3水平截面颊舌向实际宽度(7.87±0.66)mm与CT投影测得值(7.95±0.52)mm接近,无显著差异(P>0.05)。结论:锥形束CT为上颌前磨牙双根鉴别X线平片加大垂直角投照法提供了理论依据。     

锥形束CT数字化牙颌模型测量的可靠性和准确性评价

目的:研究应用锥形束CT(CBCT)获取数字化牙颌模型测量的可靠性。方法:选择正畸治疗患者的石膏模型40副,采用CBCT扫描石膏牙颌模型,对其进行测量,并与手工测得的结果进行一致性相关系数(concordance correlationcoefficient,CCC)和均数差(mean difference,MD)比较。结果:所有测量项目的CCC在0.847~0.993之间,大部分测量项目的均数差小于0.25mm,但CFF6、PWF5和PWM6的均数差分别为0.34mm、0.63mm和1.49mm。结论:锥形束CT数字化牙颌模型测量的可靠性好,精确度高。牙尖测量的准确性最高,中央窝次之,腭侧龈缘最低点的测量准确性最低。     

锥形束CT辅助诊断慢性牙周炎牙槽骨缺损的准确性研究

目的 评价锥形束CT在辅助诊断慢性牙周炎牙槽骨缺损中的准确性及其与根尖X线片、曲面体层X线片和临床检查结果的一致性,以期为锥形束CT在辅助诊断慢性牙周炎骨缺损中的应用提供依据.方法 采用单纯随机抽样法纳入2012年12月至2013年12月就诊于西安交通大学医学院附属口腔医院牙周黏膜科并确诊为慢性牙周炎的患者75例,分别进行锥形束CT、根尖X线片及曲面体层X线片检查,用华海MedViewer及EzlmPlant软件测量牙槽骨缺损的高度,同时行全口牙周探诊检查,确定附着丧失水平及釉质牙骨质界至牙槽嵴顶的距离,作为影像学检查结果的临床评判指标.对临床测量值及锥形束CT测量牙槽骨的缺损值行配对t检验,采用单因素方差分析评价4种方法检测近远中牙槽骨缺损的结果,以P＜0.05为差异有统计学意义.结果 共纳入1 494颗牙,8 964个位点,3种影像学方法中仅锥形束CT可以检测出唇(颊)或舌(腭)侧牙槽骨破坏;对近远中向牙槽骨缺损的测量结果显示,锥形束CT[近中:(5.5±0.4)mm,远中:(5.6±0.8)mm]与根尖X线片[近中:(5.1±0.6)mm,远中:(5.1±0.8)mm]、锥形束CT与全口曲面体层X线片[近中:(4.9±0.4)mm,远中:(4.9±0.8)mm]的测量结果相比差异均有统计学意义(P值均＜0.01),临床探诊[近中:(5.5±0.6)mm,远中:(5.5±0.6)mm]与根尖X线片及全口曲面体层X线片相比差异亦有统计学意义(P值均＜0.01),但临床探诊与锥形束CT的测量结果相比差异无统计学意义;锥形束CT与临床探诊对不同区域1 494颗牙齿牙槽骨缺损差异的检出情况一致,两种方法检测不同区域牙齿及1 494颗牙不同位点的牙槽骨缺损差异均无统计学意义(P值均＞0.05),两种方法不存在牙位及位点差异性.结论 锥形束CT与临床探诊在评价不同牙位及不同位点的牙槽骨缺损中一致性最高;锥形束CT在判断慢性牙周炎骨缺损方面与临床检查结果具有较高的一致性,优于根尖X线片和曲面体层X线片.     

锥形束CT辅助诊断根尖囊肿累及范围的临床应用研究

目的：分析锥形束CT（CBCT）辅助诊断慢性根尖囊肿累及范围的临床应用效果。方法：选取2013年4月－2014年4月诊断为慢性根尖囊肿的CBCT三维重建影像资料42例，观察X线根尖片及CBCT三维重建影像资料，综合评价CBCT在辅助诊断慢性根尖囊肿累及范围中的应用效果。结果：CBCT诊断慢性根尖囊肿累及范围的能力显著优于X线根尖片，42例均能通过CBCT准确诊断囊肿累及患牙，并于根管治疗后根尖囊肿如期愈合。结论：CBCT能够辅助诊断慢性根尖囊肿的累及范围，并指导临床医生判断受累患牙。     

锥形束CT在根尖周病诊断中的临床价值研究

目的对比研究锥形束CT和根尖片对根尖周病的诊断价值。方法分别对35位患者,总共41颗诊断为根尖周病的患牙用锥形束CT和根尖片进行扫描,阅片后作出判断。结果通过锥形束CT发现有37颗牙存在根尖阴影,而根尖片仅发现27颗牙存在根尖阴影。结论锥形束CT比根尖片诊断根尖周病的准确度高,临床上锥形束CT可以辅助诊断疑难病例。     

牙科数字成像系统、锥形束CT及透明牙对离体第一恒磨牙根管系统诊断价值的对比性研究

目的 对比分析牙科数字成像系统（RVG）、锥形束CT（CBCT)及透明牙3种检查方法在诊断离体第一磨牙根管系统的价值,分析第一磨牙根管影像解剖学与根管解剖学的对应关系,为第一磨牙根管治疗提供影像解剖依据。方法 拍摄269颗离体第一磨牙颊舌向、近远中向RVG和CBCT后,再制作根管染色透明牙,应用RVG、CBCT和透明牙对各牙根中上2/3、根尖1/3区根管系统和管间交通支进行分类统计,以评估CBCT在根管诊断中的应用价值。结果 CBCT对第一磨牙主根管中上2/3区的显示率达96.55%;CBCT、透明牙对第一磨牙根尖1/3区根管系统的显示差异有统计学意义（P<0.05）。上、下颌第一磨牙近中根变异较大,双或多根管与管间交通支发生率均较高。结论CBCT与透明牙在显示第一磨牙主根管系统（牙根中上2/3区）方面基本等效;在根尖1/3区透明牙对细小分歧根管的显示明显优于CBCT;RVG对多根管牙根、根尖细小分歧根管的显示明显受限;上、下颌第一磨牙近中根双或多根管与管间交通支发生率均较高。CBCT对牙根、根管的显示具有清晰直观、准确快捷的优点,是目前无创诊断根管疾病最可靠方法。     

正畸伸长重度牙周炎患牙引导牙槽骨增量初探

目的评价正畸伸长重度牙周炎患牙引导牙槽骨增量的临床疗效。方法回顾性纳入2018年10月至2022年5月于北京大学口腔医学院·口腔医院正畸科及牙周科就诊的12例牙周炎伴错畸形患者资料(男性5例, 女性7例), 年龄(38.8±6.6)岁(24～49岁), 共16颗因重度牙周炎致无法保留的上切牙。使用正畸固定矫治器对患牙进行正畸伸长, 收集正畸伸长前后锥形束CT影像资料。使用体素重叠技术对同一例患者两时点锥形束CT影像进行叠加, 在矢状面上测量牙槽骨高度、厚度及牙槽骨根尖区面积, 使用三维重建技术测量正畸伸长前后牙槽骨改建体积, 并分析与牙槽骨改建体积相关的影响因素。结果患牙伸长距离为(2.37±0.82)mm。正畸伸长后, 唇侧和舌侧牙槽骨高度分别增加(1.11±0.79)和(0.98±0.79)mm, 近中和远中侧牙槽骨高度分别增加(1.10±0.78)和(0.86±1.08)mm, 根尖区牙槽骨厚度减少(0.30±0.31)mm, 牙槽骨根尖区面积增加(6.84±5.86)mm2, 牙槽骨改建体积为(53±49)mm3。牙槽骨改建体积与牙齿伸长距离、根尖区及近中侧牙槽骨厚度呈中度正相...     

锥形束CT和数字化牙片测量牙齿长度的准确性研究

目的评价锥形束CT(cone-beam computed tomography,CBCT)和数字化牙片(digital periapical radiographs,DPRs)测量牙齿长度的准确性。方法需拔牙的正畸患者拍摄CBCT,共46例患者82颗前磨牙纳入研究。利用CBCT自带软件从轴位(axial planes,APs)、矢状位(sagittal planes,SPs)和冠状位(coronal planes,CPs)测量牙齿的长度。牙齿拔出后,利用游标卡尺测量牙齿长度作为金标准。然后将牙齿放入人干头颅的相应牙槽窝内,使用分角线技术拍摄DPRs,并测量牙齿长度。比较CBCT和DPRs测量牙齿长度的准确性。结果单根前磨牙,CBCT-轴位、矢状位和冠状位的测量值均低于牙齿实际长度,但差异无统计学意义(P>0.05),而数字化牙片测量值显著高于牙齿实际长度(P<0.05)。双根前磨牙,CBCT-轴位测量值高于牙齿实际长度,CBCT-矢状位和冠状位测量值低于牙齿实际长度,但差异均无统计学意义(P>0.05)。数字化牙片测量值显著低于颊根的实际长度,高于腭根的实际长度(P<0.05)。结论 CBCT测量牙齿长度显示较高的可信度。     

牙科锥形束CT评价上颌前牙唇面形态对转矩的影响

目的研究上颌前牙的唇面形态及牙冠牙根成角关系对转矩的影响,为临床治疗中调整牙齿的转矩提供参考。方法选择206颗离体上颌前牙为研究对象,其中中切牙77颗、侧切牙68颗、尖牙61颗。利用牙科锥形束CT将全部牙齿进行扫描,在CT工具软件下进行影像的三维重建并提取全部牙的正中矢状切面图像,利用Auto CAD软件测量图像,分别测量牙冠唇面4个不同高度的切线与牙冠长轴所成的角度,以及牙冠长轴与牙根长轴所成的角度（冠根角）。结果当托槽高度为3.5～5.0 mm时,其高度每变化0.5 mm,上颌中切牙转矩变化约为1.5°,上颌侧切牙和尖牙的转矩变化约为2°。上颌中切牙、侧切牙、尖牙冠根角的均数分别为0.88°、3.87°、-3.30°。结论牙体形态的生物学变化从多方面影响矫治后牙齿的转矩角。     

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