Abstract：
OBJECTIVE: The current supraomohyoid neck dissection (SOHND) is performed above the omohyoid muscle to dissect levels I, II, and III in the levels of cervical lymph nodes. However, the anatomical boundary between levels III and IV is the inferior border of the cricoid cartilage. We investigated the anatomical relationship between the omohyoid muscle and cricoid cartilage using contrast-enhanced CT (CE-CT) images to assess the validity of the current SOHND.
METHODS: CE-CT images of the head and neck regions in patients were reviewed. The patients were divided into two groups: \"malignant tumors\" and \"others\". The vertebral levels corresponding to the positions of anatomical structures such as the intersection of the omohyoid muscle and internal jugular vein (OM-IJ), and the inferior border of the cricoid cartilage (CC), were recorded.
RESULTS: The OM-IJ was located around the seventh cervical to the first thoracic vertebra. There was a significant difference between the malignant tumor and others groups in females (p = 0.036). The CC was located around the sixth to seventh cervical vertebrae. There was a significant sex difference in each group (malignant tumor: p < 0.0001; others: p = 0.008). Both sexes tended to have lower OM-IJ than CC, and females had significantly lower OM-IJ than males.
CONCLUSIONS: This study provides clear anatomical evidence showing the difference between the SOHND dissection area and levels I, II, and III. It could be considered that in most cases SOHND invades level IV, not just levels I, II, and III, especially in female patients.
METHODS: CE-CT images of the head and neck regions in patients were reviewed. The patients were divided into two groups: \"malignant tumors\" and \"others\". The vertebral levels corresponding to the positions of anatomical structures such as the intersection of the omohyoid muscle and internal jugular vein (OM-IJ), and the inferior border of the cricoid cartilage (CC), were recorded.
RESULTS: The OM-IJ was located around the seventh cervical to the first thoracic vertebra. There was a significant difference between the malignant tumor and others groups in females (p = 0.036). The CC was located around the sixth to seventh cervical vertebrae. There was a significant sex difference in each group (malignant tumor: p < 0.0001; others: p = 0.008). Both sexes tended to have lower OM-IJ than CC, and females had significantly lower OM-IJ than males.
CONCLUSIONS: This study provides clear anatomical evidence showing the difference between the SOHND dissection area and levels I, II, and III. It could be considered that in most cases SOHND invades level IV, not just levels I, II, and III, especially in female patients.
摘要：
目的：当前的舌骨上颈清扫术（SOHND）在舌骨肌上方进行，以解剖I级，II,和III在颈部淋巴结水平。然而,III级和IV级之间的解剖边界是环状软骨的下边界。我们使用对比增强CT（CE-CT）图像研究了舌骨肌和环状软骨之间的解剖关系，以评估当前SOHND的有效性。
方法：回顾患者头颈部的CE-CT图像。将患者分为“恶性肿瘤”和“其他”两组。与解剖结构的位置相对应的椎骨水平，例如蝶骨肌和颈内静脉（OM-IJ）的交点，和环状软骨（CC）的下边界，被记录下来。
结果：OM-IJ位于第七颈椎至第一胸椎周围。女性恶性肿瘤与其他组之间存在显着差异（p=0.036）。CC位于第六至第七颈椎周围。各组存在显著的性别差异(恶性肿瘤:p<0.0001;其他:p=0.008)。两性的OM-IJ都比CC低，女性的OM-IJ明显低于男性。
结论：这项研究提供了明确的解剖学证据，表明SOHND解剖区域与I级之间存在差异，II,和III。可以认为，在大多数情况下，SOHND侵入IV级，不仅仅是一级，II,III,尤其是女性患者。
方法：回顾患者头颈部的CE-CT图像。将患者分为“恶性肿瘤”和“其他”两组。与解剖结构的位置相对应的椎骨水平，例如蝶骨肌和颈内静脉（OM-IJ）的交点，和环状软骨（CC）的下边界，被记录下来。
结果：OM-IJ位于第七颈椎至第一胸椎周围。女性恶性肿瘤与其他组之间存在显着差异（p=0.036）。CC位于第六至第七颈椎周围。各组存在显著的性别差异(恶性肿瘤:p<0.0001;其他:p=0.008)。两性的OM-IJ都比CC低，女性的OM-IJ明显低于男性。
结论：这项研究提供了明确的解剖学证据，表明SOHND解剖区域与I级之间存在差异，II,和III。可以认为，在大多数情况下，SOHND侵入IV级，不仅仅是一级，II,III,尤其是女性患者。
