背景:近年来,锥形束计算机断层扫描(CBCT)由于其高分辨率和非侵入性,已被广泛用于评估患者的根管解剖结构。由于体素尺寸是影响CBCT图像质量的重要参数之一,本研究评估了4种不同体素大小的CBCT在永久性下颌切牙双根管系统和副管(AC)检测中的诊断潜力.
方法:从牙科诊所收集了106颗拔除的下颌恒切牙,然后通过使用具有9μm的体素大小的micro-CT进行扫描。然后将牙齿固定在人类干燥下颌骨的牙槽中,并使用具有4种不同体素尺寸(300、200、250和125μm)的CBCT设备进行扫描。四名观察者根据CBCT图像盲目检测牙齿的根管形态,是否存在双根管系统,以及AC的存在与否,根据5分制评分,分别。进行接收器工作特性(ROC)分析,和DeLong检验用于比较曲线下面积(AUC)值,并将micro-CT数据作为金标准。
结果:在106颗样本牙齿中,通过Micro-CT鉴定了25个具有双根管系统的标本。4位观察者获得的数据的ROC曲线分析显示,在双根管系统的检测中,300μm体素尺寸的AUC值范围为0.765至0.889,对于250μm体素尺寸,从0.877到0.926,对于200μm体素尺寸,从0.893到0.967,和从0.914到0.967125μm体素尺寸(所有p<0.01)。总的来说,我们观察到AUC值的趋势,灵敏度,随着体素尺寸的减小,在125μm体素大小的图像中检测到明显更高的AUC值。在检测AC时,ROC曲线分析表明,在四个观察者中,300μm体素尺寸的AUC值范围为0.554至0.639,对于250μm体素尺寸,从0.532到0.654,对于200μm体素尺寸,从0.567到0.626,对于125μm体素尺寸,从0.638到0.678。体素大小为125μm的CBCT图像在AC的检测中具有较弱的诊断潜力(AUC:0.5-0.7,所有p<0.05),较低的灵敏度范围为36.8%至57.9%,较高的专业范围为73.6%至98.8%。
结论:具有300μm体素大小的CBCT只能在下颌切牙双管系统的检测中提供中等的诊断准确性。体素大小为125μm的CBCT在双管系统的检测中具有很高的诊断价值。而在ACs的检测中显示出较低但具有统计学意义的价值。
In recent years, cone-beam computed tomography (CBCT) has been widely used to evaluate patients\' root canal anatomy due to its high resolution and noninvasive nature. As voxel size is one of the most important parameters affecting CBCT image quality, the current study evaluated the diagnostic potential of CBCT with 4 different voxel sizes in the detection of double root canal systems and accessory canals (ACs) in permanent mandibular incisors.
A total of 106 extracted mandibular permanent incisors were collected from the dental clinics, and then were scanned by using micro-CT with a voxel size of 9 μm. The teeth were then fixed in the tooth sockets of human dry mandibles and scanned by using a CBCT device with 4 different voxel sizes (300, 200, 250, and 125 μm). Four observers detected in blind the root canal morphology of the teeth according to the CBCT images, and the presence or absence of a double root canal system, and the presence or absence of ACs, were scored according to a 5-point scale, respectively. Receiver operating characteristic (ROC) analysis was performed, and DeLong test was used to compare the area under the curve (AUC) values and the micro-CT data was taken as a gold standard.
Among 106 sample teeth, 25 specimens with a double root canal system were identified by the micro-CT. ROC curve analysis of the data obtained by the four observers showed that in the detection of double root canal systems, the AUC values ranged from 0.765 to 0.889 for 300 μm voxel size, from 0.877 to 0.926 for 250 μm voxel size, from 0.893 to 0.967 for 200 μm voxel size, and from 0.914 to 0.967 for 125 μm voxel size (all p < 0.01). In general, we observed a trend that the AUC values, sensitivity, and specialty increased with the decrease in the voxel size, and significantly higher AUC values were detected in 125 μm voxel size images. In the detection of ACs, ROC curve analysis showed that among the four observers, the AUC values ranged from 0.554 to 0.639 for 300 μm voxel size, from 0.532 to 0.654 for 250 μm voxel size, from 0.567 to 0.626 for 200 μm voxel size, and from 0.638 to 0.678 for 125 μm voxel size. CBCT images at a voxel size of 125 μm had a weak diagnostic potential (AUC: 0.5-0.7, all p < 0.05) in the detection of AC, with a lower sensitivity ranging from 36.8 to 57.9% and a higher specialty ranging from 73.6 to 98.8%.
CBCT with 300 μm voxel size could only provide moderate diagnostic accuracy in the detection of a double canal system in mandibular incisors. CBCT with a voxel size of 125 μm exhibited high diagnostic value in the detection of double canal systems, while showing low but statistically significant value in the detection of ACs.