This is Episode twelve: Oral Cavity Two — The Clinically Node-Negative Neck: Elective Dissection, Not Watchful Waiting.In Episode Eleven, we established that oral cavity cancer is a surgical disease and that depth of invasion drives staging and management. We introduced the concept of elective neck dissection for the clinically negative neck. Now we're going to go deep on the evidence. The cN0 neck is one of the classic oral board scenarios. The examiner will present a patient with early oral tongue cancer, clinically and radiographically negative nodes, and ask you what to do with the neck. Observation is only defensible in very superficial tumors with a depth of invasion of three millimeters or less; otherwise, elective treatment is standard. The D'Cruz trial changed everything—and you need to know it inside and out.