Editing Neck dissection (section)

==Division of the neck into levels and sublevels==
[[File:Neck dissection2.jpg|thumb|right|Modified radical neck dissection]]

To describe the lymph nodes of the neck for neck dissection, the neck is divided into 6 areas called ''Levels''. The levels are identified by Roman numeral, increasing towards the chest. A further Level VII to denote lymph node groups in the superior [[mediastinum]] is no longer used. Instead, lymph nodes in other non-neck regions are referred to by the name of their specific nodal groups.
* Level I – This includes the submental and submandibular lymph nodes.
*: The [[submental triangle]] (sublevel IA) is bounded by the anterior belly of the [[digastric muscle]]s (laterally) and the [[hyoid]] (inferiorly). The [[submandibular triangle]] (sublevel IB) is bounded by the body of the [[mandible]] (superiorly), the [[stylohyoid]] (posteriorly), and the anterior belly of the digastric (anteriorly).
* Level II – This includes lymph nodes of the upper jugular group and is divided into sublevels IIA and IIB.
*: Level II is bounded by the inferior border of the hyoid (inferiorly), the base of [[skull]] (superiorly), the [[stylohyoid muscle]] (anteriorly) and the posterior border of the SCM (posteriorly). Sublevel IIA nodes lie anterior to the SAN. Sublevel IIB nodes lie posterior to the SAN.
* Level III – This includes lymph nodes of the middle jugular group.
*: This level is bounded by the inferior border of the hyoid (superiorly) and the inferior border of the [[cricoid]] (inferiorly), the posterior border of the [[sternohyoid]] (anteriorly) and the posterior border of the SCM (posteriorly).
* Level IV – This includes lymph nodes of the lower jugular group.
*: This level is bounded by the inferior border of the cricoid (superiorly), the [[clavicle]] / [[Sternum|sternal]] notch (inferiorly), the posterior border of the sternohyoid (anteriorly) and the posterior border of the SCM (posteriorly).
* Level V – This includes posterior compartment lymph nodes.
*: This compartment is bounded by the clavicle (inferiorly), the anterior border of the [[trapezius]] (posteriorly), the posterior border of the SCM (anteriorly). It is divided into sublevels VA (lying above a transverse plane marking the inferior border of the anterior cricoid arch) and VB (below the aforementioned plane).
* Level VI – This includes the anterior compartment lymph nodes.
*: This compartment is bounded by the common [[carotid]] arteries (laterally), the hyoid (superiorly), the [[suprasternal notch]] (inferiorly).