下颌神经管在CBCT与曲面体层片上的一致性评价

目的:对比分析下颌神经管在CBCT与曲面体层片上可见性的一致性,探讨影响下颌神经管在图像上可见性的非病变因素。方法:选取2013年12月~2014年2月期间在华西口腔医院同时拍摄了CBCT与曲面体层片的患者92例,由2位放射科医师同时观察患者的CBCT片与曲面体层片。把CBCT及曲面体层片上的下颌神经管从颏孔至下颌升支前缘处平分为1、2、3三个区域,分为0、1、2、3四个等级的分对下颌神经管的可见性进行评分。结果:2位医师间的内部一致性检验符合标准。CBCT上,区域1平均得分为2.120,区域2为2.337,区域3为2.533;曲面体层片上,区域1平均得分为1.772,区域2为1.973,区域3为2.207。越往后区域可见性越高。结论:CBCT对下颌神经管的可见性显著高于曲面体层片,仅有1％的下颌神经管在曲面体层片上可见,在CBCT上不可见。下颌神经管的可见性与年龄呈相关性,年龄越大,可见性越低。     

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.     

CBCT在颌骨牙骨质瘤的诊断与手术中的临床应用

目的：通过CBCT了解颌骨牙骨质瘤与周围组织的关系,为临床诊断与手术进路提供参考。方法：收集颌骨牙骨质瘤患者CBCT扫描数据资料,观察牙骨质瘤与周围组织的关系。结果：CBCT对颌骨三维重建及多平面观察,可明确牙骨质瘤的大小、边界及毗邻关系。结论：CBCT对指导上下颌骨牙骨质瘤的诊断与手术进路的选择是一种有用的方法。     

CBCT和数字曲面体层片在颌骨后牙区牙种植术中应用研究

目的探讨CBCT与数字曲面体层片在牙种植术中的应用价值。方法 50例(58颗)牙种植治疗患者同时采用CBCT和数字曲面体层检查方法,将得到的术前颌骨牙槽骨量和术后骨结合的影像结果对照,分析差异性。结果下颌后牙区牙槽骨量不足CBCT检出阳性率为28.57%;数字曲面体层影像检查检出阳性率为7.14%。经过χ2检验,P<0.05,差异有统计学意义。上颌后牙区牙槽骨量不足CBCT和数字曲面体层影像检查检出阳性率分别为36.36%、9.09%。经过χ2检验,P<0.05,差异有统计学意义。种植牙术后3个月种植体未发生骨结合的阳性率,CBCT检出阳性率为3.45%(2/58);数字曲面体层片检出阳性率为8.62%(5/58),两者无统计学差异(P>0.05),实际临床检测发现仅1例未发生骨结合,阳性率为1.72%(1/58)。结论 CBCT是种植牙术前目前颌骨骨量测量较为可靠方法。CBCT与数字曲面体层片相比,数字曲面体层片存在变形,牙槽骨高度数据测量值普遍偏大。在术后检查中CBCT能更清晰地反映种植体周围骨质,评估种植手术的成功与否及对上部结构的修复有重要的指导意义。     

下颌阻生第三磨牙与下颌管位置的曲面体层X线片和锥形束CT观察

目的 观察分析在曲面体层x线片上人群中下颌阻生第三磨牙(impacted mandibular third molar,IMTM)与下颌管位置关系的类型,并对二者关系密切的病例行锥形柬CT(conc beam computed tomography,CBCT)检查,了解二者实际位置关系.为临床制定IMTM拔除手术方案提供参考.方法 观察390例(645侧)曲面体层X线片,将IMTM与下颌管的位置关系的影像分为3种类型:①无接触类,二者影像无任何重叠或接触;②点状接触类,二者之间影像仅为点状接触;③部分重叠类,二者影像部分重叠或有较大范围接触.统计3种类型的构成比.曲面体层X线片显示IMTM与下颌管影像呈部分重叠或较大范围接触的部分病例行CBCT检查,观察曲面体层X线片IMTM与下颌管关系密切者中,IMTM实际突破下颌管壁所占的比例.结果 390例(645侧)IMTM的曲面体层X线片影像中,无接触类441侧(68.4%);点状接触类149侧(23.1%);部分重叠类55侧(8.5%).对31例(50侧)曲面体层X线片上显示IMTM与下颌管呈部分重叠或较大范围接触的CBCT检查发现,25侧(50%)IMTM突破下颌管壁.结论 ①曲面体层X线片可以排除90%以上IMTM与下颌管关系不密切的病例;②曲面体层X线片IMTM与下颌管影像呈部分重叠或较大范围接触表现的病例有必要行CBCT进一步检查.     

锥形束CT在下颌骨肿瘤和肿瘤样病变检查中的应用

目的:探讨锥形束计算机体层摄影术( CBCT)在下颌骨肿瘤和肿瘤样病变检查中的应用价值。方法:回顾性分析16例经病理证实的下颌骨肿瘤和肿瘤样病变的CBCT资料,包括轴面、冠状面、矢状面、曲面重建图像及VR图像,评价病变的大小、形态、范围、内部结构特征,及其与邻近牙齿、下颌神经管的解剖关系,并与术中所见相比较。结果:13例病变中,牙瘤6例,成釉细胞瘤3例,角化囊性瘤3例,骨化性纤维瘤2例,骨纤维异常增殖症2例,所有病例的形态、范围、内部结构特征,以及与邻近牙齿、下颌神经管的关系显示清楚,与术中所见一致。结论:CBCT扫描能够全面提供下颌骨肿瘤和肿瘤样病变的影像学信息,可作为术前常规检查。     

下颌骨骨折98例临床总结

目的:探讨下颌骨骨折的诊断和治疗方法。方法:全部下颌骨骨折病例术前拍下颌曲面体层片或下颌X线平片进一步确诊,然后行"颌骨坚固内固定术"加"间断颌间弹性牵引术"。结果:98例下颌骨骨折病例均得到了明确的诊断,获得了理想的复位固定和良好的咬合关系,无张口受限等并发症发生。结论:下颌曲面体层片或下颌骨X线平片仍然是目前诊断下颌骨骨折的最佳辅助检查手段,且经济、实用。"颌骨坚固内固定术"加"间断颌间弹性牵引术"是治疗下颌骨骨折的理想术式,值得基层医疗单位推广使用。     

CBCT在颌骨骨折诊断中的应用

目的:探讨锥形束CT(CBCT)在上、下颌骨骨折诊断中的应用价值。方法:对76例不同类型的上、下颌骨骨折患者的常规X线平片、全景片、锥形束CT(CBCT)影像学资料骨折显示情况进行分析。通过将术前被显示和诊断的骨折线,与术中所见相比较,得出该影像检查的骨折诊断准确率。结果:下颌骨骨折CBCT准确率可达100%,上颌骨骨折CBCT的准确率约为96.1%,CBCT能确定颌骨骨折的部位、类型及移位方向。结论:CBCT对颌骨骨折是有效的影像学检查方法,有利于临床治疗方案的制定和实施。     

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。     

CBCT与全颌曲面断层在下颌后牙区种植术中的诊断价值比较

目的：比较牙科专用锥形束CT（CBCT）与全颌曲面断层片在下颌后牙区种植术中的诊断价值。方法：对57例（69侧）下颌后牙区种植术的患者进行术前术后的CBCT影像学检查,得到下颌骨多层位影像,将其与全颌曲面断层影像进行比较,判断其检查结果的一致性。采用SPSS13．0统计软件对结果进行x2检验。结果：牙槽骨骨量不足的阳性检出率,CBCT与全颌曲面断层片分别为30．43％和15．94％,P=O．0437,差异具有统计学意义;术后种植体未发生骨结合的检出率,CBCT和全颌曲面断层片分别为3．45％和9．20％,P=O．1193,差异无统计学意义。结论：CBCT与全颌曲面断层片相比,可以更准确评估下颌后牙区种植术前牙槽骨骨量,并在术后的检查中能更准确地反应种植体骨结合的情况。     

Radiographic features of enostosis determined with limited cone-beam computed tomography in comparison with rotational panoramic radiography

Objectives Radiographic findings of enostosis often resemble those of focal condensing osteomyelitis of inflammatory origin, and the location and state of these lesions cannot be precisely diagnosed using rotational panoramic radiography. Consequently, a differential diagnosis approach is required. This study examined the situation and characteristics of mandibular enostosis using limited cone-beam computed tomography (CBCT) in comparison with rotational panoramic radiography. Methods Forty-four radiopaque lesions were examined on rotational panoramic radiography and CBCT. The lesions were diagnosed as enostosis from radiographic features on CBCT that had been performed for other clinical diagnoses or dental treatments. For each lesion, the site, margin, density, and relationship to tooth roots were determined on rotational panoramic radiography, and the shape of the cortical bone was determined on CBCT. Results Enostosis occurred in the premolar region of the mandible in 25 cases (57%) and displayed numerous patterns of relationships to adjacent teeth on rotational panoramic radiography. All lesions displayed an ovoid external form on rotational panoramic radiography. On CBCT, enostosis arose from buccal cortical bone in 13 cases and from lingual cortical bone in 25 cases; a lingual origin was suspected in the remaining six cases. The periodontal ligament space of adjacent teeth near the lesion was clearly apparent on both rotational panoramic radiography and CBCT. Conclusions Rotational panoramic radiography and occlusal radiography cannot diagnose exactly the location and state of enostosis. The diagnosis of enostosis can be difficult for lesions influenced by secondary infection in the roots of surrounding teeth; diagnosis in these cases may be facilitated by clarifying the manifestation involving the periodontal ligament space of adjacent teeth and confirming bone thickening arising from the inner surface of cortical bone.     

Mandibular Incisive Canal: Cone Beam Computed Tomography

Purpose: Panoramic radiography is often used to analyze the anatomical structure of the teeth, jaws, and temporomandibular joints. Cone beam computed tomography (CBCT) imaging allows multiple axial slices of the image to be obtained through these anatomical structures. The aim of this study was to assess CBCT compared with panoramic radiography to verify the presence, location, and dimensions of the mandibular incisive canal. Materials and Methods: CBCT scan images and panoramic radiographs of 89 subjects were compared for the presence of the mandibular incisive canal, its location, size, and anterior‐posterior length. The distance between the incisive canal and the buccal and lingual plate of the alveolar bone, and the distance from the canal to the inferior border of the mandible and the tooth apex were also measured. A paired t‐test was used to calculate any significant difference between the two imaging techniques. Results: Eighty‐three percent of the CBCT scans showed the presence of the incisive canal, as did 11% of the panoramic radiographs. The range of the incisive canal diameter, as seen in the CBCT scans, was from 0.4 × 0.4 mm to 4.6 × 3.2 mm. The mean length of the canal was 7 ± 3.8 mm. The distance from the inferior border of the mandible to the canal was 10.2 ± 2.4 mm, and the mean distance to the buccal plate was 2.4 mm. The apex–canal distance (in dentate subjects) was 5.3 mm. Conclusion: The presence, location, and dimensions of the mandibular incisive canal are better determined by CBCT imaging than by panoramic radiography.     

Is there a relationship between dental crowding and the size of the maxillary or mandibular apical base?

Objective:To determine whether apical base size is related to dental crowding.Materials and Methods:Digital scans of dental casts were taken of 75 untreated Class I adults to measure maxillary and mandibular tooth size, dental arch perimeters, intermolar widths, and intercanine widths. Cone beam computed tomography (CBCT) images were used to measure the apical base of the maxilla and mandible, including the total cross-sectional area, five basal arch perimeters and five basal arch widths. Principal components factor analyses were performed to evaluate the relationships between the apical base size and tooth-size-arch-length discrepancies (TSALD).Results:The dental arch and maxillary apical base measures were significantly larger in males than females. There were only limited sex differences in mandibular apical base size. The dental arch measurements were smaller in subjects with greater upper and lower TSALD. Maxillary and mandibular apical base dimensions were positively interrelated. Low-to-moderate correlations were found between the size of the maxillary apical base and TSALD. The size of the mandibular apical base was not related to upper or lower TSALD. Tooth size showed little to no relationship with TSALD.Conclusions:Although maxillary apical base size is related to maxillary and mandibular crowding in subjects with Class I malocclusion, mandibular apical base size is not.     

The use of cone beam computed tomography as an aid in evaluating and treatment planning for mandibular cancer.

PURPOSE: The workup for oral malignancy involving the mandible typically involves a head and neck exam, laboratory studies, a panoramic radiograph, and computed tomography (CT) or magnetic resonance imaging of the head and neck to evaluate the primary lesion and cervical lymph nodes. Panoramic plain film radiography of the mandible is often unreliable for detecting bony invasion; therefore, other imaging studies are necessary before staging is complete. Bony invasion is typically imaged with the use of conventional CT scanners. In this article we relate the use of cone beam computed tomography (CBCT) to image the mandible with less cost and morbidity to the patient and its use in the evaluation and treatment planning of mandibular cancer. MATERIALS AND METHODS: A retrospective review of 3 patients with mandibular malignancies was performed. All patients had a panoramic radiograph, magnetic resonance imaging, and chest radiograph, in addition to laboratory studies. CBCT scans were ordered, after bony involvement was suspected, and compared with the other imaging studies. RESULTS: Two patients with squamous cell carcinoma of anterior mandible and 1 patient with osteogenic sarcoma were reviewed. In all cases CBCT aided the evaluation of the mandible. The cone beam panoramic view, as part of the CBCT, was used to determine extent of resection. CONCLUSION: CBCT can accurately aid in evaluating and treatment planning for malignant tumors of the mandible with less cost and decreased radiation to the patient relative to conventional CT.     

Comparative study of clinical manifestation,plain-film radiography,and computed tomographic scan in arteriovenous malformations of the jaws

OBJECTIVE: The purpose of this study was to summarize the clinical manifestation, plain-film radiography, and computed tomographic (CT) scan features of arteriovenous malformations (AVMs) of the jaws on the basis of a series of 12 patients. STUDY DESIGN: This study group comprised twelve patients with AVM of the jaws from February 1996 to February 2001. Seven cases were located in the mandible, and 5 in the maxilla. Both plain-film radiography and CT scan were available for all cases. For the patients with lesions in the mandible, panoramic, posterioanterior, and lateral mandibular views were applied. Waters' position view and panoramic radiography were indicated for AVMs of the maxilla. RESULTS: Each patient with AVM of the maxillary bone had involvement of adjacent soft tissues. Various radiographic signs were noted, including erosion, coarse trabeculae, and apparent lack of any radiographic change, and CT scans featured cystic expansion of alveolar process with broken cortex. The radiographic signs and CT scan features of AVMs in the mandible were related to involvement of surrounding soft tissues. If involvement of the adjacent soft tissues was found, "soap bubble" radiolucency was shown radiographically and osteolytic expansion with perforation of cortex was present on CT scan. In cases without surrounding soft tissue involvement, the various radiographic signs included multilocular or unilocular radiolucency or coarse trabeculae; osteolytic expansions with intact cortex were found on CT scan. CONCLUSION: AVMs of the jaws showed intraosseous osteolytic expansion on CT scan but had variable appearance on plain-film radiographs.     

Comparative assessment of panoramic radiography and CBCT imaging for radiodiagnostics in the posterior maxilla

Objective

The purpose of this study was to assess whether and how the information obtained by means of cone beam computed tomography (CBCT) on maxillary posterior teeth differs from that obtained by panoramic radiography.

Materials and method

From 157 subjects (mean age 48 years, range 19–84 years; 89 females) referred to the oral imaging center, a pair of panoramic and CBCT images was selected for further analysis. Both imaging modalities were analyzed to determine the topographic relationship of maxillary teeth to the sinus floor. Pathologic conditions, apical periodontitis, and presence of soft tissue thickening were also examined with both techniques.

Results

CBCT showed an intimate relationship of the first and second molar with the maxillary sinus in 54 and 38 %, respectively. Thirty-nine apical periodontitis lesions causing reactive changes in the maxillary sinus were detected by CBCT, while just six of them were diagnosed with panoramic imaging. A total of 26 teeth with apical extension to the maxillary sinus were detected with CBCT, from which two could be identified with panoramic radiography.

Conclusion

This study emphasizes that anatomical and pathological involvement of the maxillary sinus in relation to posterior teeth is considerably high. It is of clinical importance that the 3D nature of CBCT imaging allowed a better assessment of the relationship between the maxillary sinus and posterior root apices compared to the low detection on panoramic radiographs.

Clinical relevance

CBCT imaging can be a valuable adjunct in radioanatomical and radiodiagnostic observations in the posterior maxilla. It may better visualize maxillary sinus involvement for posterior upper teeth than panoramic radiography.     

A retrospective radiographic evaluation of the anterior loop of the mental nerve: Comparison between panoramic radiography and cone beam computerized tomography

Objectives: To compare the prevalence and the length of mental loop, measured with panoramic radiography (PR) and cone beam computerized tomography (CBCT). Material and Methods: PG and CBCT images where analyzed by a single calibrated examiner to determine the presence and the position of the mental foramen (MF), its distance to the lower mandible border, the anterior length of the mental loop (ML) and the bone quality in 82 PR and 82 CBCT. Results: ML was identified in 36.6 % of PR and 48.8 % of CBCT. PR showed a magnification of 1.87 when compared to CBCT. The mean of anterior extension of the inferior alveolar nerve and the distance to the inferior border of the mandible was higher for PR (2.8 mm, sd 0.91 mm on the PR , range 1.5 to 4.7 mm and 1.59, sd 0.9 on the CBCT ,range 0.4 to 4.0 mm) Conclusions: There is a magnification in PR images with respect to those of CBCT. The differences between CBCT and PR with regards to the identification and length of the ML are not statistically significant. Identification and accuracy measurements of ML did not depend on the bone quality. Considering that two dimensional imaging provides less accurate and reliable information regarding the anterior loop, a CBCT scan could be recommended when planning implant placement in the anterior region. Key words:Mental loop, mental nerve, mental canal, preoperative implant planning, panoramic tomography, cone beam computerized tomography.     

Three-dimensional images contribute to the diagnosis of mucous retention cyst in maxillary sinus

Objective: To evaluate the detection of mucous retention cyst of maxillary sinus (MRCMS) using panoramic radiography and cone beam computed tomography (CBCT). Study Design: A digital database with 6,000 panoramic radiographs was reviewed for MRCMS. Suggestive images of MRCMS were detected on 185 radiographs, and patients were located and invited to return for follow-up. Thirty patients returned, and control panoramic radiographs were obtained 6 to 46 months after the initial radiograph. When MRCMS was found on control radiographs, CBCT scans were obtained. Cysts were measured and compared on radiographs and scans. The Wilcoxon, Spearman and Kolmorogov-Smirnov tests were used for statistical analysis. The level of significance was set at 5%. Results: There were statistically significant differences between the two methods (p<0.05): 23 MRCMS detected on panoramic radiographs were confirmed by CBCT, but 5 MRCMS detected on CBCT images had not been identified by panoramic radiography. Eight MRCMS detected on control radiographs were not confirmed by CBCT. MRCMS size differences from initial to control panoramic radiographs and CBCT scans were not statistically significant (p= 0.617 and p= 0.626). The correlation between time and MRCMS size differences was not significant (r = -0.16, p = 0.381). Conclusion: CBCT scanning detect MRCMS more accurately than panoramic radiography. Key words:Mucous cyst, maxillary sinus, panoramic radiograph, cone beam computed tomography.     

传统全景片和锥形束CT重建全景片测量牙轴近远中倾斜度的对比研究

目的 比较传统全景片和锥形束CT（CBCT）重建全景片用于测量牙轴近远中倾斜度的准确性。方法 收集15名个别正常志愿者的石膏模型,在模型上确定上下颌从左侧第一磨牙到右侧第一磨牙的牙体长轴和平面的标记点,制作放射显影装置,志愿者佩戴放射显影装置拍摄全景片和 CBCT片。分别在石膏模型、全景片和 CBCT重建全景片上测量牙轴近远中倾斜度。利用多元方差分析和 Dunnett-t检验比较3种测量方法的差异。结果 3种测量方法间的差异有统计学意义（P=0.00）。与模型测量相比,全景片组中12个牙位有2个牙位（上下颌第二前磨牙）测量结果的差异有统计学意义（P=0.00）,CBCT组12个牙位的差异均无统计学意义。结论 评价牙轴近远中倾斜度时,传统全景片存在一定误差, CBCT重建全景片是一种更为有效的评价手段。     

Demonstration of the accessory mental foramen using rotational panoramic radiography compared with cone-beam computed tomography

Objective: Rotational panoramic radiography is routinely used in dental practice. It has not been clarified, however, whether an accessory mental foramen can be demonstrated using this technique. The visibility of accessory mental foramina on rotational panoramic radiographs was compared with those on para‐panoramic images reconstructed from cone‐beam computed tomographic (CBCT) images. Materials and methods: A total of 365 patients (130 males and 235 females) were retrospectively analyzed. Para‐panoramic images were reconstructed from CBCT images with the accessory mental foramen/foramina using three‐dimensional visualization and measurement software, and then the accessory mental foramen on rotational panoramic images was compared with that on para‐panoramic images. Results: A total of 37 accessory mental foramina were observed in 28 patients on CBCT images. The rate of being able to visualize the accessory mental foramen or bony canal between the point of bifurcation from the mandibular canal and the accessory mental foramen on rotational panoramic radiographs was 48.6% (18 of 37 accessory mental foramina). Conclusion: Approximately half of the accessory mental foramina‐positive CBCT images demonstrated the accessory mental foramen, or bony canal between the point of bifurcation from the mandibular canal and accessory mental foramen on rotational panoramic radiographs. To cite this article:
Naitoh M, Yoshida K, Nakahara K, Gotoh K, Ariji E. Demonstration of accessory mental foramen using rotational panoramic radiography compared with cone‐beam computed tomography.
Clin. Oral Impl. Res. xx , 2011; 000–000.