[Study on distribution and drainage of lymphatic vessels of tongue]

To investigate the distribution and drainage of lymphatic vessels of tongue, and to provide anatomical evidence for treatment of tongue cancer.

Indirect lymphatic injection was employed, combined with clearing method with winter green oil and corrosive cast technique, to study the distribution of lymphatic vessels of tongue. Anatomical methods were used to detect the sentinel lymph nodes in different region of tongue.

The lymphatic vessels of dorsal mucosa composed of lymphocapillary vessels and anstomosing side branches were present by superficial and deep capillary networks. The distribution of lymphatic networks extend from tip to base and from one board to another, and was not influenced by the sulcus tenninalis and median lingual sulcus. Lymphatic vessels in the muscular portion communicated with lymphocapillary network of dorsal and ventral mucosa, which made the lymphatic vessels of tongue to be an integrity network structure. These characters of distribution influenced the lymphatic drainage of tongue. The results showed principal sentinel lymph nodes (SLNs) for anterior part of tongue were submental lymph nodes, submandibular lymph nodes and juguloomohyoid lymph nodes, for lateral part and middle part of tongue were submandibular lymph nodes, jugulodigastric lymph nodes and thyroid lymph nodes, and for root part of tongue were jugulodigastric lymph nodes. SLNs for every injection region were all presented at bilatral neck, but the frequency of stained SLNs at homolateral neck was more than that at contralateral neck.

The lymphatic vessels of tongue arranged like a network, which made the lymphatic drainage at various ways and made the distribution of sentinel lymph nodes to be bilateral and dispersive.