A calculus in the submandibular (Wharton) or parotid (Stensen) duct with upstream ductal dilatation — the stone's position along the duct and its size decide endoscopic, transoral or gland surgery.
Orient first
- About 80% involve the submandibular gland; most submandibular stones are radiopaque.
- Obstruction causes meal-related swelling; infection produces sialadenitis and abscess.
- Stone position (distal duct, hilum, intraglandular) is the surgical question.
Acquire the study
- High-frequency linear probe over both submandibular and parotid glands and along each duct; sour stimulus can distend the duct.
The manoeuvre
- Duct: follow Wharton duct from the gland hilum toward the floor of the mouth — dilated duct diameter in mm.
- Stone: echogenic focus with posterior acoustic shadow; size in mm and distance from the hilum.
- Gland: size, echo pattern, vascularity on colour Doppler compared with the contralateral gland; intraglandular abscess.
What confirms it
- A calculus within the duct or gland with upstream ductal dilatation.
What licenses you to exclude it
- A normal-calibre duct without a stone on ultrasound excludes obstructive sialolithiasis of the examined gland; small radiolucent stones can be missed.
The classic misread
- Calling a calcified lymph node or phlebolith a salivary stone — follow the duct.
- Missing a distal stone near the papilla that lies outside the usual field of view.