A Comprehensive Study of Anatomy, Connections & Clinical Significance
The submandibular ganglion is a small, fusiform-shaped parasympathetic ganglion of the head and neck. It is also known as the submaxillary ganglion in older texts.
It is one of the four parasympathetic ganglia of the head and neck, the others being:
The submandibular ganglion is situated:
The ganglion "hangs" from the lower border of the lingual nerve by two nerve filaments:
Like all parasympathetic ganglia of the head and neck, the submandibular ganglion carries three types of nerve fibres. Only the parasympathetic fibres synapse here; the others merely pass through.
Sympathetic fibres provide vasomotor control to the blood vessels of the submandibular and sublingual glands.
Sympathetic stimulation causes vasoconstriction → reduced blood flow → reduced salivary secretion (thick, mucous saliva).
The sensory root is derived from the lingual nerve, which is a branch of the mandibular nerve (CN V3) – the third division of the trigeminal nerve.
The chorda tympani also carries special visceral afferent (SVA) fibres for taste from the anterior 2/3 of the tongue. These taste fibres travel through the ganglion but do NOT synapse here. Their cell bodies are in the geniculate ganglion of CN VII.
The ganglion gives off the following branches:
Multiple direct secretomotor branches pass directly from the ganglion to the submandibular gland. These are postganglionic parasympathetic fibres that stimulate serous and mucous secretion.
A small branch rejoins the lingual nerve via the anterior filament and travels with it to reach the sublingual gland. Provides secretomotor innervation.
Fine branches supply the small mucous glands of the floor of the mouth and oral mucosa.
Sympathetic fibres that passed through the ganglion continue as vasomotor branches to the blood vessels of the submandibular and sublingual glands.
The submandibular ganglion is a peripheral parasympathetic ganglion. Its histological features are:
| Feature | Submandibular | Ciliary | Pterygopalatine | Otic |
|---|---|---|---|---|
| Location | On hyoglossus, above submandibular gland | Orbit, lateral to optic nerve | Pterygopalatine fossa | Infratemporal fossa, below foramen ovale |
| Topographic CN | CN V3 (Lingual nerve) | CN III (Oculomotor) | CN V2 (Maxillary) | CN V3 (Mandibular) |
| Functional CN | CN VII (Facial) | CN III (Oculomotor) | CN VII (Facial) | CN IX (Glossopharyngeal) |
| Preganglionic nucleus | Superior salivatory nucleus | Edinger-Westphal nucleus | Superior salivatory nucleus | Inferior salivatory nucleus |
| Preganglionic path | CN VII → Chorda tympani → Lingual n. | CN III → Short root | CN VII → Greater petrosal n. → Nerve of pterygoid canal | CN IX → Lesser petrosal n. |
| Target organs | Submandibular & sublingual glands | Sphincter pupillae, ciliary muscle | Lacrimal, nasal, palatine glands | Parotid gland |
| Sympathetic root | Facial artery plexus | Internal carotid plexus | Internal carotid plexus | Middle meningeal artery plexus |
Although classically associated with the parotid gland, aberrant regeneration of parasympathetic fibres can occur after submandibular gland surgery. Parasympathetic fibres may reinnervate sweat glands of the skin, causing gustatory sweating (sweating and flushing of skin during eating).
The ganglion can be targeted for nerve block in cases of:
During surgical removal of the submandibular gland, the surgeon must be aware of the ganglion's proximity to:
Damage to the chorda tympani or submandibular ganglion results in loss of parasympathetic secretomotor supply to the submandibular and sublingual glands.
The chorda tympani can be injured during:
Effects of injury:
Botulinum toxin (Botox) can be injected into the submandibular gland or near the ganglion to treat:
Drugs that block muscarinic receptors (e.g., atropine, hyoscine) reduce salivary secretion by blocking the effect of acetylcholine released by postganglionic parasympathetic fibres at the gland.
Stones in the submandibular duct (Wharton's duct) can cause obstruction and swelling. The ganglion's secretomotor drive continues, but outflow is blocked → painful swelling especially during meals.
80% of salivary calculi occur in the submandibular gland due to the upward course of Wharton's duct and the mucous nature of secretion.
Understanding the consequences of nerve injuries in the submandibular region is essential for clinical practice.
| Nerve Injured | Cause | Sensory Loss | Motor Loss | Autonomic Effect |
|---|---|---|---|---|
| Lingual Nerve | Mandibular block, submandibular surgery | Loss of general sensation – anterior 2/3 tongue, floor of mouth | None (sensory only) | Loss of taste (chorda tympani component), reduced salivation |
| Chorda Tympani | Middle ear surgery, parotid surgery | Loss of taste – anterior 2/3 tongue | None | Reduced submandibular & sublingual secretion; dysgeusia |
| Hypoglossal Nerve (CN XII) | Submandibular gland excision, neck dissection | None | Ipsilateral tongue paralysis; tongue deviates to injured side on protrusion | None |
| Marginal Mandibular Branch (CN VII) | Submandibular gland excision, parotid surgery | None | Drooping of corner of mouth; inability to show lower teeth | None |
| Facial Artery | Submandibular gland excision | None | None | Reduced blood supply to face; collateral circulation usually adequate |
Small, fusiform parasympathetic ganglion; one of four in head & neck. Also called submaxillary ganglion.
On hyoglossus muscle, above deep part of submandibular gland, near posterior border of mylohyoid. Suspended from lingual nerve by two filaments.
Superior salivatory nucleus → CN VII → Chorda tympani → Lingual nerve → Posterior filament → Ganglion (SYNAPSE). Postganglionic → submandibular & sublingual glands.
Superior cervical ganglion → Facial artery plexus → Ganglion (NO SYNAPSE). Vasomotor to gland blood vessels.
Lingual nerve (CN V3) fibres pass through without synapsing. General sensation from floor of mouth and tongue.
Direct branches to submandibular gland; branch via lingual nerve to sublingual gland; branches to small oral glands; vasomotor branches.
Multipolar neurons surrounded by satellite cells, enclosed in fibrous capsule. Myelinated preganglionic and unmyelinated postganglionic fibres.
Relevant in submandibular gland surgery, chorda tympani injury, xerostomia, sialorrhoea treatment, and pharmacological manipulation of salivation.