Triangles of Neck

neck triangles — Olek Remesz (wiki-pl: Orem, commons: Orem) Modified by user:madhero88, CC BY 3.0, via Wikimedia Commons

Triangles	Subdivisions	Boundaries	Floor	Contents	Clinical relevance
Anterior
	Digastric (submandibular) – further subdivided into 3 small triangles: a. Lesser’s b. Pirogov’s c. Beclard’s	2 digastric bellies Mandible	Mylohyoid	Submandibular gland Submandibular nodes Facial nerve – Marginal mandibular branch (MMB) Facial vessels Lingual vessels Hypoglossal nerve Nerve to mylohyoid	Incision 2 finger breadth below inferior border of mandible avoids MMB of CN VII
	Submental	2 digastric bellies Hyoid	Mylohyoid	Submental nodes Anterior jugular vein	Safe incision – no arteries
	Carotid	SCM Superior belly of Omohyoid Posterior belly of Digastric	Hyoglossus Thyrohyoid Middle/Inferior constrictors of pharynx	Common carotid and bifurcation IJV CN X (and superior laryngeal nerve), XI, XII Ansa cervicalis	Contains Farabeuf’s triangle (landmark for identifying IJV): IJV, Common facial vein, CN XII
	Muscular	Superior belly of omohyoid SCM Anterior neck midline		Strap muscles (TOSS) Thyroid gland (along with superior thyroid artery, anterior jugular and inferior thyroid veins) Parathyroid gland Cervical part of trachea and esophagus	Tracheostomy and thyroidectomy Injury of superior thyroid artery – bleeding
Posterior
	Occipital	SCM Trapezius Inferior belly of omohyoid	Levator scapulae Splenius capitis Middle/Posterior scalene	Accessory nerve (CN XI) Artery – Occipital, Transverse cervical Brachial plexus – parts Cervical plexus (GLaST) – Greater auricular nerve, Lesser occipital nerve, Supraclavicular nerve, Transverse cervical nerve Deep cervical lymph nodes
	Supraclavicular or Subclavian or Omoclavicular	SCM Inferior belly of omohyoid Clavicle		Subclavian artery (3rd part) Subclavian vein (and EJV termination) Brachial plexus – trunks Supraclavicular vessels Dorsal scapular artery Phrenic nerve Deep cervical nodes	Virchow/Troisier’s node