Department of Stomatology, Tuscan Stomatological Institute, Foundation for Dental Clinic, Research and Continuing Education, Via Padre Ignazio da Carrara 39, 55042, Forte Dei Marmi, Italy.
Department of Stomatology, Faculty of Medicine and Dentistry, University of ValenciaGascó, Oliag Street 1, 46010, Valencia, Spain.
BMC Oral Health. 2021 Mar 6;21(1):100. doi: 10.1186/s12903-021-01448-9.
To introduce a theoretical solution to a posteriori describe the pose of a cylindrical dental fixture as appearing on radiographs; to experimentally validate the method described.
The pose of a conventional dental implant was described by a triplet of angles (phi-pitch, theta-roll, and psi-yaw) which was calculated throughout vector analysis. Radiographic- and simulated-image obtained with an algorithm were compared to test effectiveness, reproducibility, and accuracy of the method. The length of the dental implant as appearing on the simulated image was calculated by the trigonometric function and then compared with real length as it appeared on a two-dimensional radiograph.
Twenty radiographs were analyzed for the present in silico and retrospective study. Among 40 fittings, 37 resulted as resolved with residuals ≤ 1 mm. Similar results were obtained for radiographic and simulated implants with absolute errors of - 1.1° ± 3.9° for phi; - 0.9° ± 4.1° for theta; 0° ± 1.1° for psi. The real and simulated length of the implants appeared to be heavily correlated. Linear dependence was verified by the results of the robust linear regression: 0.9757 (slope), + 0.1344 mm (intercept), and an adjusted coefficient of determination of 0.9054.
The method allowed clinicians to calculate, a posteriori, a single real triplet of angles (phi, theta, psi) by analyzing a two-dimensional radiograph and to identify cases where standardization of repeated intraoral radiographies was not achieved. The a posteriori standardization of two-dimensional radiographs could allowed the clinicians to minimize the patient's exposure to ionizing radiations for the measurement of marginal bone levels around dental implants.
介绍一种理论解决方案，以便在后验上描述圆柱形牙科固定器在射线照片上的姿态；对所描述的方法进行实验验证。
通过矢量分析计算常规牙种植体的姿态由三个角度（phi-倾斜角、theta-滚转角和 psi-偏转角）描述。通过算法获得的射线照相和模拟图像与测试进行比较，以验证该方法的有效性、再现性和准确性。通过三角函数计算模拟图像上出现的牙种植体的长度，然后将其与二维射线照片上出现的实际长度进行比较。
本研究进行了 20 张射线照片的模拟和回顾性分析。在 40 个配件中，37 个配件的残余物≤1mm。对于射线照相和模拟植入物，也获得了相似的结果，phi 的绝对误差为-1.1°±3.9°；theta 的绝对误差为-0.9°±4.1°；psi 的绝对误差为 0°±1.1°。植入物的实际和模拟长度似乎存在很强的相关性。稳健线性回归的结果验证了线性依赖性：0.9757（斜率），+0.1344mm（截距），调整后的决定系数为 0.9054。
该方法允许临床医生通过分析二维射线照片，计算出一个实际的单角（phi、theta、psi）的后验值，并识别出未达到重复口腔内射线照相标准化的情况。二维射线照片的后验标准化可以使临床医生减少患者因测量牙种植体周围边缘骨水平而接受电离辐射的次数。
