Sialolithiasis of Submandibular Gland

Submandibular sialolithiasis is calculus formation in the submandibular gland or Wharton duct. It accounts for 80 to 90 percent of all salivary stones because the saliva is alkaline and rich in mucin and calcium, and the duct is long and runs uphill.

• Stones are of calcium phosphate and are usually radiopaque.
• Dehydration, diuretics, anticholinergic drugs and gout raise risk.
• Peak age is 30 to 60 years, with men slightly more affected.

Pain and swelling under the jaw at meals (salivary colic) that settle over an hour, progressing to persistent swelling.

• A hard stone may be felt on bimanual palpation of the floor of the mouth, and saliva may be scanty or purulent.
• Differential diagnosis: sialadenitis without stones, lymphadenitis, tumour, ranula, dental abscess, duct stricture, mucus plug, IgG4 related sialadenitis, Sjogren syndrome.
• Complications: acute sialadenitis, abscess, ductal stricture, gland atrophy, chronic sialadenitis.

Ultrasound is the first investigation.

• Ultrasound detects stones over 2 mm and ductal dilation; occlusal radiograph shows radiopaque stones in the anterior duct.
• CT without contrast for small stones; sialendoscopy is both diagnostic and therapeutic.
• Culture of pus; full blood count, CRP when infected.

Promote flow, relieve pain and remove the stone.

• Supportive: hydration with 2 to 3 litres daily, sour stimulants such as lemon or sugar free sweets, warm compresses, gland massage, avoid drying drugs, oral hygiene.
• Pharmacological: ibuprofen 400 mg three times daily with food and paracetamol 1 g every 6 hours; if infection, amoxicillin clavulanate 625 mg three times daily for 7 days, or clindamycin 300 mg four times daily in penicillin allergy.
• Procedures: manual expression of stones near the orifice; transoral duct incision for stones in the anterior duct; sialendoscopy with basket retrieval or laser fragmentation for mid duct stones; extracorporeal shock wave lithotripsy where available; submandibular gland excision for large hilar stones or recurrent disease, with protection of the lingual and marginal mandibular nerves.
• Special groups: children, sialendoscopy preferred with weight based antibiotics; pregnancy, hydration and ultrasound, with surgery deferred; older adults, review of drying drugs.
• Red flags: floor of mouth swelling, fever, airway symptoms, hard mass, weight loss, persistent swelling after stone removal.
• Follow-up: review at 4 to 6 weeks; ultrasound to confirm clearance and repeat if symptoms recur.