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??Objective     To explore the value of cone-beam computed tomography??CBCT??in diagnosing complicated periapical diseases. Methods    Forty teeth were studied. X-ray periapical images??taken at horizontal 0°and distal 10° angulated projection??and CBCT were taken at the same time. The presence of apical lesions and their extents??if existed??were observed??periapical index??PAI??scoring system was used for assessing lesions extent. Compare the difference on diagnosis and judgement of causes. Results    Disagreement was found between X-ray periapical image and CBCT in lesions assessment and PAI scoring. More valuable information was obtained by CBCT. Conclusion    CBCT is a very useful tool in the diagnosis of complex periapical diseases.     

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??Objective    To analyse the accuracy of cone-beam computed tomography??CBCT??in the diagnosis of combined periodontal-endodontic lesions??in order to provide the foundation for the application of CBCT in the diagnosis of combined periodontal-endodontic lesions. Methods    Randomly select fifty-five tooth of fifty-five patients with combined periodontal-endodontic lesion  in Department of Periodontics of Dalian Stomatological Hospital. Each patient received radiovisiography??RVG????CBCT and clinical examination. Clinical examination determined the level of attachment loss and the distance from the bone of the cemento enamel junction to the top of the alveolar crest. Compare the values of alveolar bone defect  and the diagnosis of furcation involvement by clinical examination??RVG and CBCT. Results????????RVG could measure the mesial and the distal aspects of alveolar bone defect. Clinical examination and CBCT could measure the mesial??the distal??the buccal and the palatal aspects of alveolar bone defect. The single-factor variance analysis showed that the 3 methods had statistical difference in the measurement of mesial and distal alveolar bone defect in combined periodontal-endodontic lesions ??mesial??F = 3.56??distal??F = 5.37??P < 0.001??. The results of measurement of bone defects in mesial and distal aspects were shown that there were significant statistical differences in the results of RVG vs. CBCT and RVG vs. clinical examination??P < 0.05??. The comparison of  the measurement of alveolar bone defect in each sites by CBCT and clinical examination showed no statistical differences??P > 0.05??. In the incidence of diagnosis of furcation involvement of combined periodontal-endodontic lesions??there were significant statistical differences between RVG and CBCT and between RVG and clinical examination??P < 0.001??. There were no statistical differences between CBCT and clinical examination??P > 0.05??. Conclusion    CBCT and clinical examination have consistency in evaluation of the degree of alveolar bone defect and the incidence of furcation involvement in the combined periodontal-endodontic lesions??both being superior to RVG??and CBCT is the highest in the accuracy of the three methods.     

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目的 探讨髁状突位置与错(殆)畸形的关系.方法 选择2009年3月至2010年12月厦门市口腔医院正畸科收治的各类错(殆)患者60例(各15例),通过锥形束CT(CBCT)获取影像资料,应用Dolphin 11.0软件在垂直于髁状突长轴的斜位测得颞下领关节前、上、后间隙值,运用Pullinger分析法判断髁状突在关节窝的位置.结果 安氏Ⅱ1、Ⅲ类错(殆)患者的髁状突在关节窝内大部分为前移位,安氏Ⅰ类错(牙合)患者的髁状突在关节窝内居中位,安氏Ⅱ2患者的髁状突在关节窝大部分居后位.结论 (1)不同类型的错(殆)畸形髁状突位置存在差异;(2)CBCT结合Dolphin 11.0软件可作为研究颞下颌关节的有效手段.     

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目的    评价锥形束CT（cone beam computed tomography,CBCT）用于颌骨内埋伏牙定位的价值。方法    选择2009年9月至2010年3月中山大学附属口腔医院诊治的,用常规口腔全景片和定位片无法清楚判断埋伏牙形态、大小及与邻牙位置关系的颌骨内埋伏牙患者28例。所有患者行CBCT扫描,对所得数据处理后获得牙体表面三维立体图像及任意平面图像和任意曲面断层图像。结果        CBCT从多个角度完整清晰地显示埋伏牙的形态、大小、萌出方向、唇腭侧位置及与邻牙位置的关系。根据CBCT图像,18例26颗埋伏牙采用相应的手术进路拔除,10例10颗形态正常且非倒置的埋伏牙采用去骨开窗正畸治疗。所有患者顺利完成手术,术前诊断与术中判断完全一致,准确率为100%。术后创口均Ⅰ期愈合,无感染、邻牙损伤等并发症发生。结论    CBCT可直接、准确地反映埋伏多生牙的位置,为临床诊断和治疗提供可靠信息。     

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锥形束CT是一种临床辅助检查方式,它可以提供高质量、高精度的颌面部三维图像。因其图像精度高、扫描时间短、辐射剂量小等优势,在口腔临床医学中得到广泛应用。本文对锥形束CT在牙体牙髓疾病领域的应用进展做一综述。     

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??Objective    To measure the anatomic buccolingual angulation values of the maxillary alveolar process based on CBCT images in order to form a basis for the implant treatment planning?? including the design of implant position and angulation. Methods    A random sample of 51 CBCT images were selected and analyzed. The NewTom 5G CBCT data sets were reformatted at a 0.5-mm spacing?? with the inferior border of the region of interest parallel to the occlusion plane of maxillary teeth. Twenty-four buccolingual cross-sectional images of the maxillary alveolar process were obtained for buccolingual angulation measurements. Results    Mean or median values of the buccolingual angulation of maxillary alveolar process ranged from about 0 degree to more than 40 degrees. Cross-sections distal to the premolar region showed a statistically higher proportion of vertical process ??angulation equals to 0 degree???? compared to cross-sections corresponding to maxillary premolars and anterior teeth region ??P < 0.05??. There were no statistical differences between the angulation of alveolar process both from the right side and left side and from males and females patients ??P > 0.05??. Conclusion    The buccolingual angulation of maxillary alveolar process decreases from anterior teeth region through the premolars region to the molars region?? with the lateral incisor and canine region being the most inclined bucally and a high proportion of the molars region being nearly vertical. Knowing average values of buccolingual angulation of maxillary alveolar process before dental implantation may help the clinician plan the position and orientation of implants?? especially when an implant surgical template is not available.     

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??Periodontal tissue is an important structure to maintain teeth stability and distribute the occlusal force of the teeth. It is often evaluated by imaging methods in clinical practice. Compared with traditional dental imaging equipment??cone-beam CT??CBCT??has the advantages of accurate imaging??high spatial resolution and lower effective radiation dose. CBCT can assess periodontal tissue accurately??but the accuracy has tissue specificity. This review summarized the technical characteristics of CBCT and its application progress in the evaluation of periodontal tissue.     

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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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??Objective    To measure the anatomic buccolingual angulation values of the mandibular alveolar process based on CBCT images in order to help determine the implant angulation at the implant treatment-planning phase. Methods    A random sample of 51 CBCT images were selected and analyzed. The NewTom 5G CBCT data sets were reformatted at a 5-mm spacing??with the inferior border of the region of interest parallel to the base of the mandible. Twenty-four buccolingual cross-sectional images of the mandibular alveolar process of each CBCT scan were obtained for angulation measurements by NNT5.6 software. Results    The mean or median values of the buccolingual angulation of the mandibular alveolar process??ranging from 1.8 degrees to 28.5 degrees??were obtained. There were no statistically significant differences on the angulation values of the alveolar process between the right side and left side or between male and female patients??P??0.05??. The number of buccally-inclined alveolar process cross-sections increased from cross-section NO.8 to NO.11??and decreased from cross-section NO.14 to NO.17??which were statistically significant??P??0.05??. Conclusion    The mean or median values of the buccolingual angulation of mandibular alveolar process increase gradually from the anterior tooth region via the premolar region to the second molar region. Most of the mandibular alveolar process cross-sections at the anterior teeth region incline buccally??while most of those at the premolar region and all of those at the molar region incline lingually. Knowing buccolingual angulation values of the mandibular alveolar process before dental implantation may help the clinician plan the orientation of implants.     

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目的    评价自制中心定位导向杆引导空心环钻用于种植牙手术的效果。方法    于2008年10月至2010年3月淄博市中心医院口腔科用自制中心定位导向杆引导空心环钻进行种植牙备洞手术,并取出洞内骨块进行骨移植。通过体外动物实验和临床应用观察其效果,并与传统方法比较。结果    体外动物实验表明,用自制中心定位导向杆引导空心环钻备洞速度较传统方法快,更换钻头的次数明显减少,所用时间是传统的1／2,备洞后取出骨块成功率100 %;在临床应用中与麻花钻形成的洞型效果相同,植骨的估量足够,愈合效果良好。结论    自制中心定位导向杆能改良种植手术,适合临床广泛应用。     

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??Cone beam computed tomography ??CBCT?? was first used in the field of dentistry by Italy scholars in 1990s. In recent years CBCT has been widely used in the oral and maxillofacial radiology because of its advantages?? such as short scanning time?? high resolution?? and low dose of radiation. This article reviewed the recent researches to summarize the role CBCT in the diagnosis of salivary gland diseases??     

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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。     

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目的对上颌前牙区颌骨的骨量及唇侧骨皮质厚度进行测量分析,为正畸治疗植入微种植支抗钉的安全区提供参考依据。方法对2010年9月至2011年6月来大连市口腔医院就诊的25例成人患者行锥形束CT扫描及三维重建,测量距上颌牙槽嵴顶3、6、9、12mm4个水平上颌中切牙、侧切牙、尖牙根间区近远中向、唇腭向的距离以及唇侧骨皮质厚度。结果 (1)在距上颌牙槽嵴顶3、6、9mm水平中切牙根间近远中向距离均最宽,唇侧骨皮质均最薄;(2)在距牙槽嵴顶9mm水平中切牙与侧切牙根间近远中向距离最窄;(3)在4个测量水平侧切牙与尖牙根间唇侧骨皮质均最厚;(4)唇腭向在距牙槽嵴顶9mm及以上水平,中切牙根间骨厚度最薄,中切牙与侧切牙根间骨厚度最厚。25例中仅3例前牙区各牙根长度超过12mm,在距牙槽嵴顶12mm水平能测出根间近远中向距离,均较宽。结论通过对扫描后颌骨影像的分析,明确了前牙区颌骨的骨量及唇侧骨皮质厚度,为植入微种植支抗钉的安全区提供参考依据。     

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??Objective    To evaluate the position of maxillary impacted canines and resorption of neighboring incisors with cone beam computed tomography ??CBCT??. Methods    Impacted maxillary canines in sixty-seven patients were selected and scanned by the Planmeca ProMax 3D at Stomatological Hospital of Jilin University from Dec.2015 to Jan.2017. The three-dimensional images were obtained by Invivo 5.4.5 software. Each impacted canine was positioned and the root resorption of adjacent incisors was observed in sagittal??coronal and axial views. Results    In sagittal plane view??except 10 horizontal impacted canines ??12.0%?? and 1 inverted impacted canine ??1.2%????33.7% of impactions were labial??30.1% were palatal??and 22.9% were middle. In coronal plane view??12.0% of the cusp tips of maxillary impacted canines were near the crown of the adjacent incisor??42.2% were near cervical third of the root of the adjacent incisor??24.1% were near middle third of the root of the adjacent incisor??9.6% were near apical third of the root of the adjacent incisor??and 12.0% were near the root tip of the adjacent incisor.In axial plane view??65.1% of impactions were mesial??12.0% of impactions were distal??and 9.6% were middle. About 17.9% lateral incisors had root resorption??and 9.7% central incisors ??13?? had root resorption??the difference being statistical ??P < 0.05??. Conclusion    CBCT is a better way in the diagnosis and analysis of the position and root resorption of maxillary impacted canines??which provides guidance to the treatment.     

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目的通过体外模型对比研究锥形柬CT和根尖片对根管纵裂的诊断价值。方法收集2010—2011年郑州大学口腔医学院和肇庆市口腔医院因正畸或牙周病拔除的健康离体单根牙60颗,根管预备充填后,去除根充材料,再用根管钉用轻力使40颗牙根纵裂：20颗完全型牙根纵裂、20颗不完全型牙根纵裂;其余20颗完整牙根为对照。按正常牙位排列置于石膏模型上,分别用根尖片和锥形束CT扫描,阅片后作出诊断。结果根尖片与CBCT诊断根管纵裂的敏感度差异有统计学意义（P〈0．05）。CBCT诊断根管治疗后完全型牙根纵裂和不完全型牙根纵裂的差异无统计学意义（P〉O．05）。结论CBCT比根尖片诊断根管治疗后牙根纵裂的敏感度高,临床上可用CBCT辅助诊断早期牙根纵裂。     

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目的：探讨锥形束CT（ cone beam CT,CBCT）在下颌阻生第三磨牙（ impacted mandibular third molar,IMTM）拔除术前设计中的应用价值。方法选择2012年9月至2013年3月在沈阳医学院附属中心医院口腔科门诊就诊,根尖片或曲面平展片检查显示下颌管（MC）与IMTM根尖相邻或相重叠的病例55例（60颗牙）,行CBCT检查,根据CBCT所提供的影像资料,判断IMTM周围组织情况,采用涡轮钻分牙拔除IMTM。结果55例患者均未出现下牙槽神经损伤情况。结论 CBCT较传统影像学检查方法成像更清晰,定位更准确,尤其有利于颊舌向位置关系的显示。对于中低位的IMTM应行CBCT检查以避免拔牙过程中损伤相邻组织结构。     

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??Objective    To analyze the correlation between OSAHS children's minimal width measured in cephalometrical film and the minimal cross section area in CBCT to determine the accuracy of airway 2D measurement in the diagnosis of airway obstruction. Methods    48 OSAHS children??10-12y??diagnosed by PSG were selected. All the subjects took cephalometrical film and CBCT at the same time. We got the airway volume and minimum cross section area by inputing DICOM form data into the dolphin. Make the Pearson correlation analysis concerning the minimum width and minimum cross section area. Results    The minimal upper airway site measured in cephalometrical film was at the same place where the minimal cross section area lied. The mean value of the most narrow sagittal width was??3.79 ± 2.40??mm??the minimal cross section area measured in CBCT was??103.30 ± 34.47??mm2. Pearson correlation R = 0.670??P < 0.05??. Conclusion    2D and 3D upper airway measurement in OSAHS children has strong correction. Cephalometrical film can reflect the airway condition and can be used in the primary diagnosis of airway obstruction site and degree.     

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目的通过显微CT体外评价,比较3种不同直径羟磷灰石颗粒外部间隙分布情况,探讨材料外部间隙对临床运用的影响。方法 2014年3—4月于广州科学城显微CT实验室对颗粒直径分别为0.25~1 mm、0.4~1 mm、1~2 mm的3种人工骨材料进行体外固定,采用显微CT扫描,评价各自的间隙排列。结果 1~2 mm组羟基磷灰石颗粒压实堆积后显微CT下显示材料颗粒排列松散,颗粒团块间存在较大空隙,间隙率为61.75%;0.25~1 mm和0.4~1 mm组材料颗粒排列较为均匀,颗粒团块间存在间隙较小,间隙率分别为27.33%和42.44%。结论显微CT可用于颗粒移植材料的微观物理参数评估,0.25~1 mm组羟磷灰石颗粒压实后颗粒团块内部排列紧密,临床上有利于植骨后稳定成骨空间。     

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??Development of dentistry has entered into the digital era?? all kinds of digital equipment and technologies have sprung up. The use of these technologies makes the diagnosis and treatment results more predictable. As a useful tool in dentistry??cone beam CT??CBCT?? plays an important role in diagnosis and treatment. This article will focus on application of CBCT in endodontics.