Salivary Stones (Sialolithiasis)
Incidence
- Submandibular > parotid (50:1) due to:
- Gland secretions are more viscid with high calcium concentration.
- Duct ascends upwards, leading to inadequate drainage.
- Orifice lies in the floor of the mouth, liable to be blocked by food particles.
Predisposing Factor
- Infection: (chronic sialoadenitis) due to change of pH of saliva + provide nidus for stone (pus cells).
- Stasis: causes stagnation and infection.
Pathology
- Number: single or multiple.
- Site: inside gland or duct.
- Nature: Calcium + magnesium + phosphorus + carbonate.
Complication
- Obstruction of duct → sialectasis + sialadenitis.
- Salivary fistula.
Symptoms
- Mainly asymptomatic or may present with:
- As chronic sialadenitis (Episodes of pain followed by relief) especially after eating.
Signs
- If acute on top of chronic sialoadenitis.
Investigation
- Plain X-ray: stone in the submandibular gland is radio-opaque in 80% of cases due to high calcium concentration.
- Sialography: best in parotid stones as they are radiolucent. May show dilated ducts.
- Ultrasound: shows the stone.
Treatment
- Surgical (according to the site of stone)
- Stone inside the gland substance
- Submandibular gland stone → Submandibular sialadenectomy.
- Parotid gland stone → Superficial conservative parotidectomy.
- Stone inside the duct
- Peeping stone from orifice → meatotomy.
- Stone in duct → removed through the mouth under local anesthesia.
- Submandibular sialoadenectomy if recurrent.