Structure
The submandibular glands lie on the internal surface of the mandible, divided into two parts by the posterior edge of mylohyoid. The superficial part lies on the inferior side of mylohyoid and is significantly larger. The deep part lies on the superior/internal side of mylohyoid and gives off the submandibular duct. The submandibular duct passes anteriorly and medially to end in the sublingual papilla near the midline, adjacent to the lingual frenulum. Submandibular lymph nodes are located near the mandiblular part of the gland.
Relations
The submandibular gland is internal to the mandible and inferior to the floor of the mouth. The mandible is posterior.
Neurovascular Supply
Arterial Supply
Arterial supply to the submandibular gland is derived from facial and lingual arteries.
Venous Drainage
Blood is returned via lingual and facial veins.
Lymphatics
The submandibular nodes lie in close proximity to the gland, or within its structure. Lymph flows from this region to the upper deep cervical nodes (level II).
Innervation
The submandibular ganglion is the source of neural supply to the submandibular gland. This small ganglion is associated with the lingual nerve as it passes anteriorly along the floor the mouth. Parasympathetic fibres arrive via the chorda tympani, a branch of the facial nerve VII. Sympathetic fibres are derived from the facial artery plexus. General sensory nerves arrive from the lingual nerve (V3).
Routes of Cancer Spread
Local Invasion
Tumours may invade superiorly into the tongue and floor of mouth, inferiorly into the mylohyoid and neck, or laterally/posteriorly into the mandible.
Lymphatic Spread
Lymph will usually travel to upper deep cervical nodes, including the jugulo-omohyoid node.
