Course and Topography of the Lingual Artery
The artery branches off the external carotid artery just above the superior thyroid artery, occasionally forming a common trunk with the facial artery known as the truncus linguofacialis. It arches above the greater horn of the hyoid bone, running forward and medially. The vessel enters the floor of the oral cavity by passing deep to (medial to) the m. hyoglossus muscle. Afterward, the artery continues toward the apex of the tongue between the m. genioglossus and m. longitudinalis inferior muscles, lying close to the inferior surface of the organ.
Branches of the Lingual Artery
During its course, the artery gives off several key branches:
- Sublingual artery (a. sublingualis) — supplies the tissues of the floor of the oral cavity, the sublingual salivary gland, and the gingiva.
- Deep lingual artery (a. profunda linguae) — the terminal continuation of the lingual artery, running within the body of the tongue to its apex, where it anastomoses with the contralateral vessel.
- Dorsal lingual branches (rr. dorsales linguae) — multiple branches ascending to supply the posterior dorsum of the tongue, mucous membrane, palatine tonsil, and soft palate.
- Suprahyoid branch (r. suprahyoideus) — runs along the upper border of the hyoid bone to supply the suprahyoid muscles.
Surgical Significance of Pirogov's Triangle
For surgical access to the lingual artery, surgeons utilize Pirogov's triangle. Its anatomical boundaries are: superiorly — the hypoglossal nerve (n. hypoglossus, cranial nerve XII); anteriorly — the posterior border of the mylohyoid muscle (m. mylohyoideus); inferiorly and posteriorly — the tendon of the posterior belly of the digastric muscle (m. digastricus). The floor of the triangle is formed by the m. hyoglossus muscle, which separates the lingual vein (superficial to the muscle) from the lingual artery (deep to the muscle). To reach the artery, the fibers of this muscle must be carefully dissected.
Clinical Significance
Ligation of the lingual artery within Pirogov's triangle is performed during tongue surgeries to reduce intraoperative bleeding. In clinical practice, the close relationship between the vessel and the m. hyoglossus is crucial: this muscle separates the artery (lying medially/deeply) from the lingual vein and hypoglossal nerve, which course superficially to it.