All of the following are true about neck dissection except:

Neck dissection Comprehensive neck dissection Selective neck dissection Radical neck dissection(RND): Removal of lymph nodes I-V + spinal accessory nerve(SAN) + Internal jugular vein(IJV) + sternocleidomastoid muscle(SCM) Extended radical neck dissection(ERND): Radical neck dissection + removal of one or more groups of lymph nodes, non-lymphatic structures or both Bilateral radical neck dissection Modified radical neck dissection(MRND): Removal of level I-V lymph nodes with (Mnemonic: SIS) - Type I: Preserves only SAN - Type II: preserves both SAN and IJV - Type III: preserves SAN ,IJV, SCM (Functional neck dissection) Supramohyoid neck Dissection: Removal of level I-III LNs. Extended supraomohyoid neck dissection: Removal of level I-IV LNs Posterolateral Neck dissection: Removal of level II-V LNs + Suboccipital LNs + retro auricular LNs. - Lateral neck dissection: Removal of level II-V LNs + Internal jugular vein. - Central compament neck dissection: Removal of level VI LNs