Department of Surgery and Orthopedics, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
J Appl Oral Sci. 2010 May-Jun;18(3):303-7. doi: 10.1590/s1678-77572010000300019.
To assess the accuracy of coronal and sagittal CT sections to detect cavities simulating root resorption.
60 mandibular incisors were embedded in plaster bases, and cavities with 0.6, 1.2 or 1.8 mm in diameter and 0.3, 0.6 or 0.9 mm in depth (small, medium and large cavities) were drilled on the buccal surfaces with high-speed round burs with diameters of 0.6, 1.2 and 1.8 mm to simulate external inflammatory root resorption. Simulations in the cervical, middle and apical thirds of each tooth root were made randomly. The Dental Scan software was used to obtain 1-mm-thick axial images from direct scanning, which were reconstructed in the coronal and sagittal planes using 3D software (Syngo FastView). Each series was loaded into the software. Fourteen images of each tooth were reconstructed in the coronal plane and 14 in the sagittal plane. A total of 1,652 images were obtained for analysis. Series information, tooth number and the plane reconstructed were stored. The images generated were saved on a CD-ROM together with the visualization software (Syngo FastView). Images were analyzed by a previously calibrated blinded, radiologist. Cochran's Q test was conducted separately for each region analyzed followed by pair-wise comparison by the McNemar test (p=0.05).
No statistically significant difference (p>0.05) was observed in the diagnosis of simulated resorption between the apical, middle, and coronal thirds. When the axial plane was assessed separately, diagnoses were statistically different (p<0.05) among the three root thirds. The apical third differed significantly (p<0.05) from the cervical and middle thirds. Diagnostic errors were more often observed in the apical third compared to the cervical and middle thirds. Mid-sized cavities revealed no statistically significant differences (p>0.05) between planes, irrespective of the third in which the resorptions were located.
When tomographic sections are requested for the diagnosis of buccal or lingual external root resorption, sagittal sections afford the best image characterization of the resorption process.
评估冠状和矢状 CT 切片检测模拟根吸收腔的准确性。
将 60 颗下颌切牙嵌入石膏底座中，在颊面用直径为 0.6、1.2 和 1.8 毫米的高速圆锯在颊面钻取直径为 0.6、1.2 和 1.8 毫米的 0.3、0.6 和 0.9 毫米深的腔，以模拟外炎症性根吸收。随机在每个牙根的颈、中、根尖三分之一处进行模拟。使用 Dental Scan 软件从直接扫描中获得 1 毫米厚的轴位图像，然后使用 3D 软件（Syngo FastView）在冠状面和矢状面重建。将每个系列加载到软件中。每颗牙重建 14 个冠状面图像和 14 个矢状面图像。共获得 1652 张图像进行分析。存储了系列信息、牙号和重建的平面。生成的图像与可视化软件（Syngo FastView）一起保存在 CD-ROM 上。由一位经过校准的盲法放射科医生分析图像。对每个分析区域分别进行 Cochran's Q 检验，然后用 McNemar 检验进行两两比较（p=0.05）。
在根尖、中间和冠三分之一的模拟吸收诊断中，没有观察到统计学上的显著差异（p>0.05）。当单独评估轴向平面时，三个根三分之一之间的诊断存在统计学差异（p<0.05）。根尖三分之一与颈中和根尖三分之一有显著差异（p<0.05）。与颈中和根尖三分之一相比，根尖三分之一的诊断错误更为常见。无论位于何处，中等大小的腔在平面之间均无统计学差异（p>0.05）。
当要求进行颊侧或舌侧外根吸收的诊断时，矢状切片能最好地对吸收过程进行图像特征描述。
