下颌骨偏斜畸形患者与正常人群下颌管三维走向及下颌骨形态的锥形束CT分析

目的:采用锥形束CT(cone-beam computed tomography,CBCT)分析下颌骨偏斜患者下颌管的走行、位置及其与周围骨板的毗邻关系,下颌骨的形态特征,并与正常人群进行比较,为下颌骨手术提供解剖学依据。方法:纳入下颌骨偏斜的成人患者29例作为病例组,个别正常成人29名为对照组。进行CBCT扫描,利用In Vivo 5软件对下颌骨进行三维重建,定位标记点,测量下颌骨形态以及下颌管在其内的三维走行。采用SPSS 17.0软件包对测量值进行统计学分析,确定不同人群下颌骨形态及下颌管走行特点及差异。结果:1下颌支下颌管外侧壁到颊侧骨皮质的距离(BP)在0、1、2平面偏斜侧显著较对照组小(P<0.05);舌侧骨皮质厚度(LC)在各层面测量值均为偏斜侧>偏斜对侧﹥对照组,在1、5平面偏斜侧与对照组差异有统计学意义(P<0.01)。2相对于偏斜对侧和对照组,偏斜侧下颌管更靠近颊侧而远离舌侧骨板,在第一磨牙处偏斜侧与对照组的差异有显著性(P<0.05)。3偏斜(对)侧与对照组的下颌孔位置、下颌支/体长度有显著差异(P<0.05)。4对照组下颌骨体截面高度、宽度、皮质骨厚度各测量值左右侧无显著差异(P>0.05),三维形态左右基本对称,但病例组两侧部分测量值与对照组差异显著(P<0.05)。结论:下颌骨偏斜畸形患者的下颌管整体走行较正常人更靠近颊侧;偏斜侧下颌支/体长度明显较对侧小,下颌骨偏斜畸形患者下颌骨形态发育不对称,在空间结构上发生了扭转变形。     

锥形束CT在牙内陷诊断中的应用

目的:探讨牙内陷的锥形束CT影像特征。方法:收集同济大学附属口腔医院就诊的40例患者其49枚牙内陷患牙的锥形束CT影像资料,对其影像特征进行分析归纳。结果:40例患者中共发现49枚牙内陷患牙,按Oehlers分型其中Ⅰ型35枚、Ⅱ型13枚、Ⅲ型1枚;发生于上颌侧切牙46枚,上颌切牙2枚,上颌尖牙1枚。49枚患牙的内陷畸形均发生于所涉及患牙的舌侧;47枚牙有1个凹陷,2枚牙有两个凹陷;3例患牙并发根尖周炎。CBCT图像显示:患牙在内陷层面,Oehlers分型为Ⅰ型的35枚和Ⅱ型13枚,在矢状面、冠状面均可见盲管征;OehlersⅢ型见双轨征;上述3型在横断面均见圆环征;大部分凹陷壁的密度与牙釉质的密度一致。结论:锥形束CT能准确诊断牙内陷,并为指导临床治疗提供可靠的影像学依据。     

四川成年人群下颌骨体副孔解剖位置的锥形束CT研究

目的 通过对下颌骨前部区域舌侧副孔数目与位置以及其与牙槽嵴顶距离的统计,得到不同年龄、性别受试者下颌骨副孔发生情况,为临床口腔手术安全操作提供参考依据.方法 选取200名符合条件的患者锥形束CT(cone-beam computed tomography,CBCT)影像资料,获取各副孔数目和位置及其到牙槽嵴顶的平均距离...     

锥形束CT在口腔医学中的应用

与传统的CT相比,锥形束CT具有空间分辨率高、放射剂量低和扫描速度快等优点,为口腔医学解决了许多疑难问题,该文就锥形束CT目前在口腔医学中的应用作一综述.     

正常青年人下颌管全长三维走向及下颌骨形态的锥形束CT测量

目的采用锥形束CT（CBCT）分析正常青年人下颌管在下颌骨内的三维位置以及下颌骨的形态特征,为临床下颌骨手术提供解剖学依据。方法 对29例个别正常进行CBCT扫描,用InVivo 5软件对下颌骨进行三维重建,定位标记点,测量下颌骨形态以及下颌管在其内的三维走行。采用SPSS 17.0软件对测量值进行统计分析。结果 下颌管舌侧骨皮质厚度明显较颊侧骨皮质薄。下颌管到颊侧骨皮质的距离从近中到远中逐渐增加,到舌侧骨皮质、牙槽嵴顶的距离从近中到远中逐渐减小,到下颌下缘的距离在第一磨牙处最小,第二前磨牙处最大。下颌体截面高度、宽度、皮质骨厚度左右侧无统计学差异,从中线至远中,下颌体截面高度、舌侧下1/3皮质骨厚度逐渐减小,上截面宽度、唇/颊侧上1/3皮质骨厚度逐渐增大。部分测量项目性别间有统计学差异。结论下颌管入下颌孔后渐渐远离舌侧而向颊侧靠近,然后又逐渐远离偏向舌侧,但其总体走行还是靠近舌侧。男性下颌骨较女性更坚厚。CBCT能精确地显示下颌神经管的走行及其与周边结构的关系。     

江西成年人群下颌骨体副孔解剖位置的锥形束CT研究

目的 应用锥形束CT（CBCT）观测江西成年人群下颌骨体副孔的分布位置,为临床安全操作提供依据。方法 选取200份江西成年人的CBCT资料,按年龄分为4组,每组男女比例相等。描述下颌骨前牙、前磨牙和磨牙各区域的副孔数目和分布位置,分析年龄、性别和左右侧因素与副孔发生率的关系。结果 发现下颌骨体副孔共1 123个,人均（5.62±2.10）个。副孔发生率自近中区域向远中降低,舌侧副孔发生率高于颊侧,男女性副孔数目无差异（P=0.195）,年龄与副孔数目呈负相关（r_s=-0.301）。下颌骨体三处副孔高频区域为:正中联合部（98.0%）,中、侧切牙牙槽突舌侧（88.0%）,前磨牙区的低位（55.0%）。结论 下颌骨副孔每人均会出现,临床需留意避免损伤副孔内容物而引起并发症。     

锥形束计算机体层摄影术在下颌骨骨折诊断及手术复位固定中的应用

目的探讨锥形束计算机体层摄影术(CBCT)对诊断及指导外科手术治疗下颌骨骨折的临床意义。方法通过临床典型病例,分析下颌骨骨折发生时作曲面断层片检查易造成漏诊或误诊,使用CBCT能从冠状位、轴向位、矢状位等不同的角度及方向观察颌骨骨折端。结果使用CBCT可以清晰了解骨折线走向及断端与骨折碎片的移位情况,能指导外科手术治疗骨折的复位与作内固定。结论 CBCT三维重建有益颌面外科制定手术计划。     

锥形束CT与根尖片在慢性牙周炎诊断中的应用比较

目的:研究CBCT在慢性牙周炎诊断中的价值。方法:通过拍摄20例慢性牙周炎患者的后牙区CBCT及根尖片,并对其进行临床牙周探针检查,比较纳入的276颗牙唇(颊)、舌(腭)、近中、远中牙槽骨缺损情况。结果:CBCT与临床探诊检查后牙区各位点牙槽骨缺损情况未见明显差异,而CBCT、临床探诊、根尖片检查后牙区近远中牙槽骨缺损可见明显差异(P＜0.05),其中根尖片所测结果小于CBCT及临床探诊,均有统计学意义(P＜0.05)。结论:在慢性牙周炎的诊断中CBCT检测较根尖片更加准确。     

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。     

锥形束CT在早期诊断牙根纵裂中的应用

目的:探讨锥形束CT对牙根纵裂(简称根裂)早期诊断的价值。方法:对23颗临床检查可疑为根裂且通过X线根尖片不能确诊的患牙,拍摄锥形束CT(cone-beam computed tomography,CBCT)观察是否存在根裂影像,分别记录为明确根裂、可疑或非根裂。根裂的CT诊断标准为:至少连续2个牙根断面上可见明显的低密度裂隙影或折断片明显移位。结果:CBCT显示23颗患牙中明确根裂17颗,可疑4颗,非根裂2颗。17颗明确根裂患牙均经拔除证实;4颗可疑患牙经4～6月观察后亦拔除并确诊为根裂;CT图像未见根裂表现的2颗患牙经临床证实无根裂。经拔除后确诊根裂的21颗患牙中,活髓牙10颗,已牙髓治疗的无髓牙11颗。CBCT的诊断敏感度为81%。结论:锥形束CT有助于牙根纵裂的早期诊断。     

Branching of mandibular canal on cone beam computed tomography images

BackgroundMandibular neurovascular canal contents may be vulnerable to damage during mandibular surgical procedures. Greater knowledge of the location and configuration of the mandibular canal can help in the safe performance of these procedures in the dental clinic. Cross-sectional CBCT imaging is a good modality for studying the course, location, configuration and accessory branches of the mandibular canal. The aim of this study was to observe the branching of the mandibular canal at different segments of the mandible and mandibular tooth groups.MethodsCBCT images of 116 mandibular halves were included in this study. The presence of secondary branching of the mandibular canal in the ramus, retromolar area, molar and premolar teeth as well as the length, diameter and angle of these branches were observed.Resultssixty nine mandibular halves (59.5%), had a main canal with no branching, There were 36 IAC (31%) with one, 8 (6.9%) with two, 2 (1.7%) with three and 1(0.9%) with 5 accessory branches. Of these secondary branches, 16 (25.4%) were in the ramus, 16(25.4%) in the retromolar, and 31(49.2%) in the molar regions.ConclusionAdvanced cross-sectional imaging modalities especially CBCT is a suitable tool for observing anatomic characteristics of mandibular canal to preserve this vital structure in surgical procedures.     

The use of cone beam computed tomography in the management of isolated orbital floor fractures

Isolated fractures of the orbital floor are diagnosed by a combination of clinical and radiographic findings. Computed tomography is considered the imaging method of choice. We describe the use of cone beam computed tomography for use in isolated fractures of the orbital floor. This shows defects in the orbital floor but with a lower dose of radiation than conventional computed tomography.     

The role of cone beam computed tomography in the management of unfavourable fractures following sagittal split mandibular osteotomy

Abstract

Cone beam computed tomography (CBCT) has been at the forefront of recent technological advances within the maxillofacial region. CBCT is useful in the accurate assessment and planning of patients undergoing orthognathic surgery. We propose that it also has a role in the post‐operative evaluation of a subgroup of patients who have suffered complications at the time of surgery. We present two cases where unfavourable splits occurred during a bilateral sagittal split osteotomy (BSSO) of the mandible. Both cases were investigated post‐operatively with CBCT with the aim of identifying the potential cause of the unfavourable split and to establish accurate localization of the condyle in the glenoid fossa following intra‐operative attempts at proximal segment control. CBCT should be considered for evaluation of the mandible following an unfavourable split where it is deemed that plain radiographs would not provide adequate information.     

Evaluation of mandibular transverse widths in patients affected by unilateral and bilateral cleft lip and palate using cone beam computed tomography

Objective:To evaluate the mandibular dental, alveolar, and skeletal transversal widths in patients affected by unilateral (UCLP) and bilateral (BCLP) cleft lip and palate and to compare the findings with a well-matched normal occlusion sample using cone beam computed tomography images.Materials and Methods:The study sample consisted of 75 patients divided into three groups: the UCLP (29 patients; mean age: 15.40 ± 3.22 years), BCLP (18 patients; mean age: 15.54 ± 3.72 years), and normal occlusion (28 patients; mean age: 15.82 ± 2.11 years) groups. Mandibular dental (intercanine and -molar), alveolar (intercanine and -molar), and skeletal (bigonial width) transversal measurements were performed three-dimensionally and analyzed using the one-way variance analysis and post hoc Tukey tests.Results:Patients affected by UCLP and BCLP had statistically significantly lower intercanine alveolar widths (P < .05 and P < .001, respectively) and larger intermolar (P < .001 and P < .05, respectively) and intermolar alveolar widths (P < .001) compared with the normal occlusion group. Furthermore, the patients affected by UCLP and BCLP had similar mandibular dental, alveolar, and skeletal transversal widths (P > .05).Conclusion:The UCLP and BCLP groups showed statistically significantly smaller values for intercanine alveolar widths and larger values for intermolar dental and alveolar widths compared with the normal occlusion group. This shows the importance of using individualized archwires according to the pretreatment arch widths of the patients affected by UCLP and/or BCLP.     

应用锥形束CT诊断颞下颌关节骨关节病的探讨

目的探讨锥形束CT（cone beam CT，CBCT）在颞下颌关节骨关节病诊断中的应用前景。方法临床诊断为颞下颌关节骨关节病（炎）、不可复（可复）性盘前移位伴骨关节病患者共48例（96侧关节）。48例同时拍摄经咽侧位x线平片和CBCT，比较两种x线检查方法的病变检出率、医师判断的重复性和一致性。结果颞下颌关节骨关节病x线表现分为6型：髁突表面皮质骨模糊消失型（I型）、表面缺损破坏型（Ⅱ型）、髁突磨平型（Ⅲ型）、骨质硬化型（IV型）、骨质增生型（V型）、囊样变型（Ⅵ型）。CBCT的检出率分别为65．63％、37．50％、27．08％、31．25％、28．13％、1．04％；经咽侧位x线平片的检出率分别为52．08％、19．79％、32．29％、23．96％、12．50％、2．08％。对每一型病变的程度和范围，同一医师两次判断或不同医师之间，对I、Ⅱ型病变的评判，经咽侧位x线平片和CBCT均有高度的一致性，Kappa值大于0．60。结论除Ⅲ型外，CBCT对每一类型的病变均有很高的检出率，所显示的病变及其部位清晰、明确。CBCT清晰的病变影像、明确的病变部位和显示多层面病变的优势，使其有望成为颞下颌关节骨关节病判定病变程度、预后以及药物治疗后效果的定量评价手段。     

2种锥形束CT诊断牙根纵裂准确性的研究

目的 比较2种锥形束CT(CBCT)诊断牙根纵裂的准确性,评估根充物、观察面、牙根观察位置对CBCT诊断的影响.方法 纳入20例单根恒下颌前磨牙作为研究对象,牙根置于人下颌骨标本第一前磨牙牙槽窝内,根据先后不同处理步骤依次拍摄4次大视野及小视野CBCT,记录下列4种情况:无根纵裂+无根充物、无根纵裂+热牙胶根充、有根纵裂+无根充物、有根纵裂+热牙胶根充.2名牙体牙髓科主治医师对结果进行判读.结果 1)无论根管内是否存在根充物,小视野CBCT诊断牙根纵裂的灵敏度均明显高于大视野CBCT(P＜0.05).2)根管内存在根充物时,小视野CBCT及大视野CBCT正确诊断根纵裂的部位均是在轴位根尖1/3区.结论 不论根管内是否存在根充物,小视野CBCT均是诊断牙根纵裂的最佳选择.根管内存在根充物时,CBCT根尖1/3受伪影影响最小,诊断牙根纵裂的灵敏度最高.     

Application of cone beam computed tomography in facial imaging science

Facial imaging is used to study the facial shapeand its developmental changes over time.This isimportant to diagnose acquired malformations,to studynormal and abnormal growth and to differentiatebetween the results of treatment and normal growth,and to validate facial recognition.The two mainmethods to study and record facial imaging are bymeans of cephalometry and anthropometry[1].Cephalometrics is the scientific study of themeasurements of the head’s     

下颌管分支的锥形束CT影像学分析

目的 运用锥形束CT（CBCT）分析下颌管分支发生的概率及其类型。方法 选取拍摄CBCT影像的216例（女104 例,男112例）患者为研究对象,对CBCT的下颌管分支影像进行观测并进行分类。结果 216例（432侧）患者中,39例（18.06%）50侧（11.57%）观测到下颌管分支,其中女18例（17.31%）,男21例（18.75%）。下颌管分支分为4类,第Ⅰ类17侧（3.94%）,第Ⅱ类11侧（2.55%）,第Ⅲ类20侧（4.63%）,第Ⅳ类2侧（0.46%）。结论 CBCT对下颌管分支的检出率较高,口腔颌面外科医生在进行下颌手术时应注意下颌管分支这一解剖变异。     

锥形束CT灰度值与密度相关性的研究

目的:研究锥形束CT灰度值与体外已知密度参考模型的相关性,并分析锥形束CT不同拍摄条件对密度测量值的影响.方法:将已知密度分别为:1.0、1.5、2.0、2.5 g/cm3的小球固定在模型上,该模型分别放置在直径约为14 cm和16 cm盛满水的圆柱形玻璃烧杯内,并在不同拍摄条件下进行锥形束CT扫描测得小球灰度值.结果...