Department of Neurosurgery, First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Road, Xi'an, 710061, Shaanxi, China.
BMC Neurol. 2020 Mar 27;20(1):111. doi: 10.1186/s12883-020-01688-2.
The top of the mastoid notch (TMN) is close to the transverse-sigmoid sinus junction. The spatial position relationship between the TMN and the key points (the anterosuperior and inferomedial points of the transverse-sigmoid sinus junction, ASTS and IMTS) can be used as a novel method to precisely locate the sinus junction during lateral skull base craniotomy.
Forty-three dried adult skull samples (21 from males and 22 from females) were included in the study. A rectangular coordinate system on the lateral surface of the skull was defined to assist the analysis. According to sex and skull side, the data were divided into 4 groups: male&left, male&right, female&left and female&right. The distances from the ASTS and IMTS to the TMN were evaluated on the X-axis and Y-axis, symbolized as ASTS&TMN_x, ASTS&TMN_y, IMTS&TMN_x and IMTS&TMN_y.
Among the four groups, there was no significant difference in ASTS&TMN_x (p = 0.05) and ASTS&TMN_y (p = 0.3059), but there were significant differences in IMTS&TMN_x (p < 0.001) and IMTS&TMN_y (p = 0.01), and multiple comparisons indicated that there were significant differences between male&left and female&left both in IMTS&TMN_x (p = 0.0006) and in IMTS&TMN_y (p = 0.0081). In general, the ASTS was located 1.92 mm anterior to the TMN on the X-axis and 27.01 mm superior to the TMN on the Y-axis. For the male skulls, the IMTS was located 3.60 mm posterior to the TMN on the X-axis and 14.40 mm superior to the TMN on the Y-axis; for the female skulls, the IMTS was located 7.84 mm posterior to the TMN on the X-axis and 19.70 mm superior to the TMN on the Y-axis.
The TMN is a useful landmark for accurately locating the ASTS and IMTS.
乳突切迹顶（TMN）靠近横窦-乙状窦交界处。TMN 与关键点（横窦-乙状窦交界处的前上点和后下点，ASTS 和 IMTS）之间的空间位置关系可作为一种新方法，用于在侧颅底开颅术中精确定位窦汇。
本研究纳入 43 例干尸颅骨标本（男 21 例，女 22 例）。在颅骨外侧定义了一个矩形坐标系，以协助分析。根据性别和颅骨侧别，将数据分为 4 组：男左、男右、女左、女右。ASTS 和 IMTS 到 TMN 的距离在 X 轴和 Y 轴上进行评估，分别表示为 ASTS&TMN_x、ASTS&TMN_y、IMTS&TMN_x 和 IMTS&TMN_y。
在这 4 组中，ASTS&TMN_x（p=0.05）和 ASTS&TMN_y（p=0.3059）差异无统计学意义，而 IMTS&TMN_x（p<0.001）和 IMTS&TMN_y（p=0.01）差异有统计学意义，多重比较表明男左和女左之间的 IMTS&TMN_x（p=0.0006）和 IMTS&TMN_y（p=0.0081）差异有统计学意义。总体而言，ASTS 在 X 轴上位于 TMN 前方 1.92mm，在 Y 轴上位于 TMN 上方 27.01mm。对于男性颅骨，IMTS 在 X 轴上位于 TMN 后方 3.60mm，在 Y 轴上位于 TMN 上方 14.40mm；对于女性颅骨，IMTS 在 X 轴上位于 TMN 后方 7.84mm，在 Y 轴上位于 TMN 上方 19.70mm。
TMN 是准确定位 ASTS 和 IMTS 的有用标志。
