Define Salivary Calculi & Sialadenitis. Describe its clinical features, complications and management.

The Concept — WHY the Submandibular Gland?

Salivary calculi (sialolithiasis) form overwhelmingly in the submandibular gland (about 80%), and understanding why explains the whole condition. The submandibular gland produces thicker, more mucinous, more alkaline saliva rich in calcium, and its duct (Wharton's duct) is long and runs uphill against gravity to open in the floor of the mouth — a perfect recipe for stasis and stone formation. A stone then obstructs salivary flow, causing swelling and predisposing to infection.

Salivary Calculi — Clinical Features

The hallmark is painful swelling of the gland at mealtimes: eating (or even the sight of food) stimulates salivation, but the obstructing stone prevents outflow, so the gland swells and aches, then gradually settles between meals. A stone may be palpable in the floor of the mouth along the duct. Recurrent obstruction predisposes to recurrent sialadenitis.

Salivary Calculi — Diagnosis & Treatment

Diagnosis is by bimanual palpation of the floor of the mouth, a plain X-ray (most submandibular stones are radio-opaque), and ultrasound, sialography or CT. Treatment depends on the site: a stone near the duct orifice can be removed intra-orally (by incising the duct), whereas a stone within the gland or a gland damaged by recurrent infection is treated by excision of the submandibular gland. Sialendoscopy is a modern minimally-invasive option.

Sialadenitis

Sialadenitis (inflammation of a salivary gland) has several forms:

• Acute bacterial (suppurative) parotitis — classically in a dehydrated, elderly or post-operative patient with poor oral hygiene, where reduced salivary flow allows Staphylococcus aureus to ascend the duct. There is a painful, hot, swollen, tender parotid, and pus may be expressed from the duct.
• Viral — mumps, typically causing bilateral parotid swelling.
• Chronic / recurrent — from obstruction, or autoimmune disease (Sjögren's syndrome).

Acute bacterial parotitis is treated with rehydration, antibiotics, oral hygiene and salivary stimulation, with drainage if an abscess forms — and, importantly, it is largely preventable by keeping post-operative patients well hydrated with good mouth care.

Complications of Obstruction

Persistent salivary obstruction has consequences beyond the mealtime pain: recurrent acute sialadenitis, formation of an abscess, and eventually chronic sialadenitis with irreversible fibrosis and atrophy of the gland (which is then best excised). Understanding this progression explains why a symptomatic stone within the gland, or a gland damaged by repeated infection, is treated by gland excision rather than repeated conservative measures.

Submandibular Gland Excision

When excision is needed, the surgeon must be aware of three nearby nerves at risk: the marginal mandibular branch of the facial nerve (injury droops the corner of the mouth), the lingual nerve (tongue sensation and taste), and the hypoglossal nerve (tongue movement). Careful technique to preserve these is central to the operation.

Viral & Autoimmune Sialadenitis

Two non-bacterial forms round out the topic. Mumps, a paramyxovirus, causes painful bilateral parotid swelling in children, and is important for its complications (orchitis, meningitis, pancreatitis). Sjögren's syndrome is an autoimmune destruction of salivary and lacrimal glands causing dry mouth and dry eyes (sicca syndrome), often with bilateral gland enlargement and a raised risk of salivary lymphoma in the long term. Recognising these prevents mislabelling every swollen gland as a stone or bacterial infection.

The practical upshot across sialadenitis is that the history usually reveals the type — mealtime pain suggests obstruction, an acutely hot tender gland in a dehydrated patient suggests bacterial infection, bilateral childhood swelling suggests mumps, and chronic dryness suggests Sjögren's — which then directs the appropriate investigation and treatment.

Principles of Management Summarised

Pulling the salivary infections and stones together, management follows three principles. First, relieve obstruction — remove a stone or dilate a stricture so saliva can flow. Second, treat infection — antibiotics, hydration and oral hygiene for acute bacterial sialadenitis, with drainage of any abscess. Third, remove the diseased gland when it is irreversibly damaged by recurrent infection or harbours a proximal stone. Underlying all of these is the recognition that salivary stasis is the common enemy, so measures that keep saliva flowing (hydration, sialogogues, good oral care) both treat and prevent these conditions.

A Summary of Principles

Across salivary obstruction and infection the theme is that salivary stasis is the common enemy: relieve obstruction, treat infection, and excise an irreversibly damaged gland — while keeping saliva flowing (hydration, sialogogues, oral hygiene) to both treat and prevent disease. Mealtime submandibular swelling means a stone; a hot tender parotid in a dehydrated post-operative patient means bacterial parotitis.

Submandibular gland is most affected — viscous mucous saliva, uphill duct.

• Salivary stones form mostly in the submandibular gland (~80%) — thick mucinous alkaline saliva + long uphill duct (Wharton's).
• Classic feature: painful gland swelling at mealtimes, settling between meals; stone often palpable in the floor of the mouth.
• Diagnose by palpation, plain X-ray (radio-opaque), ultrasound/sialography; treat by intra-oral removal (distal stone) or gland excision (proximal/recurrent).
• Acute bacterial (Staph) parotitis: dehydrated/elderly/post-op patient, hot tender parotid, pus from duct → hydration, antibiotics, oral hygiene, drainage.
• Also viral (mumps, bilateral) and autoimmune (Sjögren's); prevent bacterial parotitis with hydration and mouth care.