Types of Modified Neck Dissection include the following:
Type I: The spinal accessory nerve is preserved.
Type II: The spinal accessory nerve and the internal jugular vein are preserved.
Type III: The spinal accessory nerve, the internal jugular vein, and the sternocleidomastoid muscle are preserved.
Extended radical neck dissection:
Resection of lymph node groups and/or additional structures not included in the classic neck dissection is performed