Salivary glands: parotid, submandibular and sublingual
- Applied anatomy
Three pairs of major glands make saliva; stones favour the submandibular gland and tumours the parotid, where the facial nerve runs through.
See it in 3D: Parotid gland · Submandibular gland · Sublingual gland
What it is
The parotid, submandibular and sublingual glands, with many minor glands, produce saliva that moistens food, starts starch digestion, buffers acid and protects the teeth. Their anatomy predicts their diseases: the long, upward-running submandibular duct with thick, calcium-rich saliva makes stones; the parotid hosts most salivary tumours and carries the facial nerve through it; and any cause of reduced saliva (drugs, radiotherapy, Sjögren disease) leads to dry mouth and caries.
Applied anatomy
- Parotid duct: emerges from the front of the gland, runs over the masseter, pierces the buccinator, opens opposite the upper second molar.
- Facial nerve: forms the parotid plexus inside the gland and leaves as five branches; at risk in parotid surgery.
- Submandibular gland in the submandibular triangle; its duct is long with bends and runs upward to the floor of the mouth.
- Parasympathetic supply: glossopharyngeal nerve (via the otic ganglion) to the parotid; facial nerve (chorda tympani) to the submandibular and sublingual glands.
Clinical physiology
- About 1 to 1.5 litres of saliva a day: water, electrolytes, mucus, amylase, IgA and lysozyme.
- Parasympathetic stimulation increases flow; sympathetic stimulation (stress) reduces it.
- Saliva cleans the teeth and its calcium and phosphate protect against caries.
The major salivary glands at a glance
| Gland | Where it opens | Saliva | Typical disease |
|---|---|---|---|
| Parotid | Opposite the upper second molar | Watery, rich in amylase | Mumps, bacterial parotitis in dehydrated patients, most salivary tumours |
| Submandibular | Floor of the mouth beside the tongue | Mixed, thicker | Stones (most common site), sialadenitis |
| Sublingual | Floor of the mouth (several small ducts) | Mostly mucous | Rarely diseased; tumours here are more often malignant |
Clinical correlation
- Bacterial sialadenitis: painful red swollen gland with pus from the duct, often in dehydrated or hospitalised patients; may form an abscess.
- Mumps is the classic viral cause of parotid swelling; vaccination has made it uncommon.
- Many drugs (for blood pressure, depression, bladder control), head and neck radiotherapy and Sjögren disease reduce saliva and cause dry mouth and caries.
- A painless, slowly growing lump is the usual tumour presentation; facial palsy, pain, rapid growth or fixed nodes suggest malignancy.
Next step / Initial management
- Palpate the gland with two hands (inside the mouth and outside), milk the duct, look at the duct opening and check facial nerve function.
- Stones or sialadenitis: hydration, sialogogues (sour sweets), massage and warm compresses; antibiotics if fever or pus. Ultrasound is the first imaging.
- Refer as an emergency (same day) for floor-of-mouth swelling, breathing or swallowing difficulty, or a fluctuant abscess.
- Refer urgently (within about two weeks) to ENT for any persistent salivary lump, especially with facial weakness, pain, fixation or neck nodes; imaging and fine needle aspiration come before surgery.
- Refer routinely for recurrent stones or infections (sialendoscopy) and for dry mouth with suspected Sjögren disease (rheumatology).
Test yourself
Think of the answer, then tap the question to see it.
A man has painful swelling under the jaw every time he eats, settling an hour later. Which gland and why that one?
The submandibular gland, the site of about 85% of salivary stones: its duct is long and runs uphill, and its saliva is thicker and richer in calcium.
Where does the parotid duct open into the mouth?
On the inner cheek opposite the upper second molar, after crossing the masseter and piercing the buccinator.
A parotid lump has grown over months and the patient now has facial weakness on that side. Why is this worrying?
Facial nerve involvement by a parotid mass suggests a malignant tumour. Urgent ENT referral for imaging and fine needle aspiration.
Connections
See it in 3D3
The structures of Durgical's 3D anatomy where it is found.
Educational content; it does not replace a medical assessment and is not a clinical instruction. For a real case, follow current guidelines and specialist advice.
Sources: Anatomy, Head and Neck, Salivary Glands (StatPearls (NCBI Bookshelf), 2023); Dry Mouth (National Institute of Dental and Craniofacial Research (NIDCR), NIH, 2024); Salivary gland infections (MedlinePlus, US National Library of Medicine, 2025); Salivary gland tumors (MedlinePlus, US National Library of Medicine, 2025).
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Representative model, for educational purposes only.