Angle Orthod. 2019 Sep;89(5):758-767. doi: 10.2319/082018-612.1. Epub 2019 Mar 18.
To quantify reliability of three-dimensional skeletal landmarks and a comprehensive set of dental landmarks in cone-beam computed tomography (CBCT) and to determine the shapes of envelope of error.
Three judges located 31 skeletal landmarks and 60 dental landmarks on the pre- and posttreatment CBCT images of 22 patients. Landmark error was determined by calculating the distance of deviation of landmark locations around their average. Standard deviation and mean radial spherical error were calculated. Scatterplots were constructed to characterize envelope of error.
The midline landmarks of the cranial base were highly reliable. Bilateral skeletal landmarks tended to have larger error than midline landmarks. Among the nonconventional landmarks, fronto-zygomatic suture, condyle, and mental foramen showed relatively high reliability. However, foramen spinosum and temporal fossa showed larger errors. Gonion was the least reliable landmark. Most dental landmarks were located more reliably than skeletal landmarks. The highest reliability was found at incisal edges. Mesiobuccal cusp of first molars also showed high reliability.
There were differences in the size and shape of the distributions of errors of different landmarks. Most landmarks showed elongated envelopes. Bilateral structures tended to show greater errors than midline structures. Most dental landmarks were more reliable than skeletal landmarks.
定量分析锥形束 CT（CBCT）中三维骨骼标志点和全面的牙齿标志点的可靠性，并确定误差范围的形状。
3 位评估者在 22 名患者的治疗前后 CBCT 图像上定位了 31 个骨骼标志点和 60 个牙齿标志点。通过计算标志点位置围绕平均值的偏差距离来确定标志点误差。计算了标准差和平均径向球差。绘制散点图以表征误差范围。
颅底中线标志点具有高度可靠性。双侧骨骼标志点的误差往往大于中线标志点。在非传统标志点中，额颧缝、髁突和颏孔显示出相对较高的可靠性。然而，棘突和颞窝的误差较大。髁突是最不可靠的标志点。大多数牙齿标志点的定位比骨骼标志点更可靠。切缘的可靠性最高。第一磨牙的近中颊尖也显示出较高的可靠性。
不同标志点的误差分布大小和形状存在差异。大多数标志点的误差范围呈拉长状。双侧结构的误差往往大于中线结构。大多数牙齿标志点比骨骼标志点更可靠。
