锥形束CT在牛牙症诊断及治疗中的导航作用

牛牙症(taurodontism)是一类特有的牙体畸形,是在牙齿的发育过程中,釉牙骨质界水平向正常收缩发生障碍,并且牙髓腔在垂直方向上伸展,导致髓室底和根分叉向根方移位[1]。牛牙症在人群发病率较低,常发生于磨牙及前磨牙,Darwazeh[2]等报道高达26.7%的牛牙症患牙存在不同程度的髓石及根管钙化,伴随其特殊的髓腔形态给根管治疗造成很大的困难[3]。本文通过报道CBCT影像学分析技术辅助诊断治疗上颌第一磨牙牛牙症一例,进一步说明CBCT的应用价值。     

锥形束CT对牛牙症诊断价值的探讨

用锥形束CT辅助诊断牛牙症根折伴牙内吸收1例,锥形束CT对该症的诊断和治疗方面有重要指导意义。     

锥形束CT和曲面体层片用于牙根折裂诊断的比较

目的评价锥形束CT(CBCT)与曲面体层片(OPG)检查在根折病例中的诊断价值。方法对比研究30名患者的31颗根折裂患牙的OPG和CBCT检查结果。结果在31颗牙根折裂患牙中,OPG能明确诊断的有23颗牙齿,而CBCT能明确诊断所有患牙。结论从CBCT图像上能清晰辨别牙根纵折裂纹和纵折区牙槽骨的变化,对于根折的早期诊断意义优于OPG。     

CBCT和曲面体层片在上颌后牙区种植治疗中的诊断价值比较

目的:比较牙颌面专用锥形束CT(CBCT)与普通X线曲面体层片在上颌后牙区种植治疗中的诊断价值.方法:对75例(89侧)上颌后牙区种植牙治疗患者采用CBCT进行种植前后的影像学检查,得到上颌骨多层面冠状及矢状位影像.将其与曲面体层片进行比较,判断其与CBCT检查结果的一致性.采用SPSS11.5软件包对数据进行X2检验.结果:牙槽骨量不足的阳性检出率,CBCT和曲面体层分别为30.34%和16.85%,P=0.034,差异有统计学意义;种植体未发生骨结合的检出率,CBCT和曲面体层片分别为4.95%和11.88%,P=0.413,差异无统汁学意义.结论:CBCT与曲面体层片相比,可以更准确评估术前上颌后牙区的牙槽骨骨量,并可在术后检查中更清晰地反应种植体周围骨质.     

锥形束CT在下颌阻生第三磨牙拔除术前诊断应用的初步研究

目的 评价口腔颌面锥形束CT(cone beam CT,CBCT)确定下颌阻生第三磨牙(impacted mandibular third molar,IMTM)与下牙槽神经管位置关系,为IMTM拔除术中预防下牙槽神经损伤提供临床依据.方法 通过IMTM拔除术前曲面体层X线片检查,筛选出IMTM与下牙槽神经管存在较大范围接触或部分重叠影像表现的49例患者(60侧),进一步行CBCT检查,结合种植机微动力系统微创拔牙术中观察结果,应用诊断试验的方法评价术前CBCT检查结果的准确性.结果 术前CBCT观察IMTM突破下牙槽神经管壁判断的灵敏度82.8%、特异度87.0%,Youden指数0.69,阳性预测值88.9%,阴性预测值80.0%.两位口腔放射医师术前对CBCT共同判读的结果与术中观察结果的符合率为84.6%(44/52).对两位医师术前分别判读CBCT影像的结果进行一致性分析,Kappa值=0.80.结论 对于曲面体层X线片显示IMTM与下牙槽神经管存在较大范围接触或部分重叠影像表现的病例应用CBCT术前检查,CBCT显示的IMTM与下牙槽神经管的关系与临床实际观察结果一致性较高.

Abstract：

Objective To evaluate the diagnostic accuracy of the cone beam computed tomography(CBCT)in judging the relationship between the impacted mandibular third molar(IMTM)and the inferior alveolar canal(IAC).Methods Sixty IMTM superimposing on the canal partially or touching the canal in line on panoramic radiograms were examined by CBCT. All CBCT images of these cases were observed by two dentists respectively. Then, all these IMTM were extracted by minimally invasive surgery, and the conditions of the IMTM sockets were observed. Two dentists observed the CBCT images independently and reached a consensus. Diagnosis test was performed in this study. Results Eight IMTM sockets were bleeding during the extracted operation, and whether the IAC wall was broken could not be judged. The other 52 IMTM sockets were clear and the walls of IAC were broken in 29 IMTM extractions. The sensitivity, specificity, Youden index, positive predictive value and negative predictive value of CBCT were 82.8%, 87.0%, 88.9% and 80.0% respectively. The diagnostic accuracy judged by the two dentists and Kappa coefficient were calculated as 84.6% and 0.800. Conclusions The CBCT examination had good authenticity and reliability, and it was very helpful in predicting the actual relationship between the IMTM and IAC.     

上颌埋伏阻生尖牙在锥形束CT和曲面体层片中的位置分布及特征研究

目的　通过分析上颌埋伏阻生尖牙在曲面体层片上牙冠和牙根所在区域、牙轴倾斜度及牙齿长度,对照其在锥形束CT（cone-beam computed tomography,CBCT）上的位置,找出上颌埋伏阻生尖牙的曲面体层片预测因素。方法　选取2006—2018年于中国医科大学附属口腔医院正畸科就诊的单侧上颌埋伏阻生尖牙患者135例,共计上颌埋伏阻生尖牙135颗为研究组,同一患者对侧非埋伏阻生尖牙135颗为对照组。（1）采用NNT Viewer软件、Planmeca Dimaxis Pro软件分别对患者的CBCT图像和曲面体层片进行测量,将曲面体层片中上颌埋伏阻生尖牙近远中向位置分为5区（Ⅰ ~ Ⅴ区）,其唇腭侧位置由CBCT判定,分析两者相关性。（2）在曲面体层片中测量分析研究组与对照组牙冠及牙根的近远中向位置分布、牙轴倾斜度以及牙齿长度的差异。结果　（1）不同性别患者上颌埋伏阻生尖牙唇腭侧位置分布的差异有统计学意义（χ2 = 13.542,P = 0.001）。曲面体层片中上颌埋伏阻生尖牙牙根近远中向的区域定位与CBCT中相应阻生尖牙的唇腭侧位之间有显著相关性（r = 0. 225,P = 0.009）;但其牙冠间无相关性（r = 0.001,P = 0.991）。（2）两组尖牙牙冠及牙根近远中向位置分布差异有统计学意义（χ2值分别为219.263、68.447,均P < 0.001）。研究组较对照组尖牙牙齿长度短,牙轴倾斜度大（均P < 0.05）。结论　利用曲面体层片中上颌阻生尖牙牙根近远中向的区域定位可预测其唇腭侧位。在曲面体层片中牙根近远中向位置和牙齿长度的测量结果可用于预测上颌埋伏阻生尖牙的发生。     

锥束CT、螺旋CT和曲面断层片诊断埋伏牙的对比性研究

目的：比较锥束CT、螺旋CT与传统曲面断层片对埋伏牙诊断的精确性,评价锥束CT和螺旋CT在埋伏牙拔除手术中的诊断价值。方法：选取93名患者的93个完全骨埋伏牙作为研究对象,其中37名患者下颌完全骨埋伏牙,56名患者上颌完全骨埋伏牙。拍摄曲面断层片后,均诊断需要拔除埋伏牙,其中31位患者单纯拍摄曲面断层片,31位患者增加拍摄螺旋CT,31位患者增加拍摄锥束CT。在3组影像上测量埋伏牙大小,及其与预备开窗处骨面距离,根据测量数据进行埋伏牙拔除,手术过程中测量埋伏牙与开窗处骨板距离,埋伏牙拔除后测量牙体大小。对3组患者的各项测量数据进行比较。结果：拍摄螺旋CT和锥束CT的患者离体牙与影片测量的差值显著小于拍摄曲面断层片的患者（P〈0．01）,拍摄锥束CT的患者离体牙和影片测量的差值小于拍摄螺旋CT的患者（P〈0．01）。结论：与二维影像相比,螺旋CT和锥束CT是一种更有效的检查埋伏牙的方法,能更精确埋伏牙在复杂颌骨结构中的位置,有利于埋伏牙的诊断和治疗。     

锥形束CT在牙体牙髓病诊治中的临床应用

锥形束CT(CBCT)作为一种新型高分辨率X线成像系统,因扫描速度快、空间分辨率高、辐射剂量小、图像伪影少等优点,在口腔医学领域获得越来越广泛的应用.本文就CBCT在牙体牙髓病诊治中的应用作一综述.     

锥形束CT与曲面断层在诊断下颌骨骨折中的比较研究

目的对比研究锥形束CT与曲面断层对下颌骨骨折的诊断特点及差异。方法收集2010年4月至2010年10月共27例因颌面部外伤行锥形束CT和曲面断层检查的患者的临床资料,比较两种方法对下颌骨不同部位骨折的诊断率。结果锥形束CT在下颌骨各部位的骨折诊断中均能明确观察骨折线及断端移位情况,而曲面断层存在漏诊现象,漏诊率为27.5%（11/40）,特别是髁突及颏部骨折,漏诊率分别为35.3%和27.3%。结论曲面断层检查存在漏诊的可能,特别是髁突或颏部骨折时,漏诊率更高。建议对下颌骨骨折应结合锥形束CT检查,以避免漏诊。同时,锥形束CT三维重建在帮助医生制定手术计划方面有很大优势和广泛应用前景。     

锥形束CT在牙体牙髓病诊治中的研究进展

口腔颌面锥形束CT（CBCT）是近10余年开始应用于临床的一种新型影像学检查方法,因其检查时间短、空间分辨率高、放射剂量低、无图像失真、价格适中等优点,在口腔疾病诊治中得到广泛应用。随着技术的发展,CBCT检查在观察根尖周病变、根管治疗、诊断根管穿孔、观察牙根吸收及诊断根折等方面的优势逐渐显示出来。本文就CBCT在牙体牙髓病诊治方面的最新研究进展做一综述。     

锥形束CT在涎石症诊断中的应用价值

目的:通过比较不同的影像检查方法为涎石症患者寻找最佳的影像诊断方法.方法:分析32例涎石症患者在超声、X线、锥形束CT 3种不同影像检查方法的阳性率和阴性率,比较其敏感性、特异性、阳性预测值、阴性预测值.结果:锥形束CT的敏感性和阴性期望值(95.8％、80％)明显高于超声检查(83.3％、50％)和X线片检查(58.3％、20％),其差异有统计学意义.3种影像检查方法在特异性、阳性预测值方面的差异无统计学意义.结论:锥形束CT在诊断涎石症方面,能确定结石的数目、大小并定位,准确性高.     

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随着锥形束CT在口腔颌面部应用的开展,锥形束CT也逐渐应用于颞下颌关节疾病的影像诊断中。本文介绍锥形束CT在颞下颌关节疾病中的应用现状,包括颞下颌关节紊乱病、颞下颌关节发育畸形、关节创伤、关节强直以及关节肿瘤等,结果表明锥形束CT作为一种有价值、有前途的影像检查方法,可以用于颞下颌关节疾病特别是关节骨性改变的评估中。     

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牙种植是近年来国内飞速发展的口腔医疗技术,锥形束CT(CBCT)的出现推动了牙种植的快速发展,而牙种植的快速发展又促进了CBCT诊断和治疗计划的应用。本文从CBCT图像中可以观察到的有关上颌窦的解剖结构的改变以及临床工作中的一些治疗体会进行总结,希望能够帮助国内广大口腔种植医生了解和更好地使用CBCT,进一步推进口腔种植的发展。     

Quantification of taurodontism: interests in the early diagnosis of hypohidrotic ectodermal dysplasia

Oral Diseases (2010) 16 , 292–298 Objective: The aim of this study was to provide a quantification of taurodontism in Hypohidrotic Ectodermal Dysplasia (HED) and to report its occurrence in a cohort of HED patients to assess phenotypic–genotypic correlations. Patients and methods: Of 68 HED patients retrospectively reviewed, 16 patients aged 7–51 years were selected and compared with a control sample (n = 351). The pulp surface index of the first lower permanent molar was calculated from the panoramic radiograph of each individual, and statistical comparisons between the HED patients and the control sample were performed. Results: Whatever the genetic disorder, 81.25% of the HED patients exhibited a relative enlargement (≥1 s.d.) of the pulp. Major deviations (>5 s.d.) were respectively related to men affected by large deletion of the EDA gene or missense mutation. The autosomal recessive form was linked to a relative moderate pulp enlargement (3.44 s.d.). In NEMO forms, the increase of pulp size in men appeared to be less marked than in EDA mutations. Conclusion: This study provides for the first time an objective assessment of pulp enlargement in HED patients, and the various degrees of taurodontism depicted could be interesting dental phenotypic markers of HED forms.     

应用锥形束CT研究下颌第二磨牙根管数目和构型

目的采用锥形束CT（cone-beam computed tomography,CBCT）观察下颌第二磨牙根管数目及构型,为根管治疗提供影像学参考。方法随机调取700颗下颌第二磨牙的CBCT资料,统计下颌第二磨牙牙根数目、根管数目和构型,以及C型根管的发生率。结果下颌第二磨牙c形牙根的发生率为36．O％;2根牙的根管构型：61．1％近中根管为Ⅳ型,96．1％远中根管为I型;C形根管在根管口及根尖1／3处类型变化多。结论下颌第二磨牙牙根和根管解剖形态多样,CBCT清晰的三维影像能为根管治疗提供参考。     

Root canal morphology of maxillary second molars in a Saudi sub-population: A cone beam computed tomography study

IntroductionRoot morphology and canal anatomy of maxillary molars shows several complexities and variations. Knowledge of these is essential for successful endodontic treatment. This study aimed to investigate the morphology of the maxillary second molars in a Saudi Arabian sub-population in relation to gender, age, and nationality, as well as to analyze the anatomical symmetry between the left and right side in each individual.Methodology420 digitized cone-beam computed tomography (CBCT) scans were collected, of which 351 scans met the inclusion criteria. Number of roots and canals at three different levels of the root in each case was counted at all available sides and compared on the basis of the study variables. Statistical significance was set at P ≤ 0.05.ResultsMost of the patients (n = 323, 92%) had three roots, while two roots (n = 23, 6.6%), four roots (n = 4, 1.1%), and one root (n = 1, 0.3%) were less frequently observed. A significant correlation between female patients and the presence of two canals, while male patients showed a higher correlation with the presence of four canals at all levels. There also was a correlation between Saudi participants and the presence of four canals at all levels. No significant correlation in symmetry between the left and right side root canal anatomy was found. There was an inverse relation between the number of canals and age.ConclusionConsidering the limitations in this study, it appears that the Saudi population is more likely to have three- and two-rooted maxillary second molars, with males and females showing greater tendencies to having three and two roots, respectively.     

锥体束CT在诊断上颌磨牙腭根折裂中的应用

目的：评价X线根尖片和锥体束CT在上颌磨牙腭根折裂中的诊断价值。方法以临床检查25例可疑为腭根横折,9例腭根纵裂的患者为研究对象。拍摄X线根尖片及锥形束CT,分别根据X线片诊断标准和CBCT诊断标准对影像学检查结果做独立判断,并与拔除患牙或翻瓣术中观察结果进行比较。结果 CBCT在腭根纵裂中诊断敏感率为87.5%,X根尖片诊断敏感率12.5%。 CBCT在腭根横折中诊断敏感度为91.7%,X线片诊断敏感率为63.6%, CBCT敏感度均高于X线片(P<0.01)。结论上颌磨牙腭根折裂的临床诊断中,CBCT诊断的敏感度显著高于X线根尖片,且CBCT能准确判断折裂位置、方向及角度,具有更高的临床应用价值。     

Analysis of intensity variability in multislice and cone beam computed tomography

Objectives: The aim of this study was to evaluate the variability of intensity values in cone beam computed tomography (CBCT) imaging compared with multislice computed tomography Hounsfield units (MSCT HU) in order to assess the reliability of density assessments using CBCT images. Material and methods: A quality control phantom was scanned with an MSCT scanner and five CBCT scanners. In one CBCT scanner, the phantom was scanned repeatedly in the same and in different positions. Images were analyzed using registration to a mathematical model. MSCT images were used as a reference. Results: Density profiles of MSCT showed stable HU values, whereas in CBCT imaging the intensity values were variable over the profile. Repositioning of the phantom resulted in large fluctuations in intensity values. Conclusions: The use of intensity values in CBCT images is not reliable, because the values are influenced by device, imaging parameters and positioning. To cite this article:
Nackaerts O, Maes F, Yan H, Couto Souza P, Pauwels R, Jacobs R. Analysis of intensity variability in multislice and cone beam computed tomography.
Clin. Oral Impl. Res. 22 , 2011; 873–879.
doi: 10.1111/j.1600‐0501.2010.02076.x     

锥形束CT对微螺钉前牙根间植入区骨量的分析

目的 通过对微螺钉种植支抗前牙根间植入区骨量进行三维测量分析,为前牙根间植入位点的选择提供参考.方法 对36名成人患者的上、下颌前牙区行锥形束CT扫描及三维重建,分别测量U/L11(上/下颌中切牙根间),U/L12(上/下颌中切牙和相邻侧切牙根间),U/L23(上/下颌侧切牙和相邻尖牙根间)距上、下前牙釉牙骨质界3mm、5 mm、7 mm及9mm水平的根间距(D1)和牙槽骨宽度(D2).采用SPSS 17.0软件进行单因素方差分析和Duncan法进行两两比较.结果 相邻两牙根间最小距离D1:从大到小依次为U11＞U23＞L23＞L11＞U12＞L12,所有牙位越往根尖方向D1越大,其中只有U11,U23分别距离釉牙骨质界5mm和7mm根间距大于3mm,相邻两牙根间唇舌向牙槽骨宽度D2为:U11＞L11,U12＞L12,L23＞U23,不同水平D2值在3.82～6.62mm之间.结论 上、下颌前牙区,上颌中切牙之间及上颌侧切牙和尖牙之间的根间区是植入微种植体较理想的部位.