| 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 |
Further reading: Triangles of the neck: a review with clinical/surgical applications – PMC (nih.gov)
