Figure 3: a) Ultrasound scan showing two hilar stones, measuring 4.4 mm and 4.7 mm, in the left submandibular gland of 14-year-old girl, before treatment. The hypoechoic changes in the parenchyma of the gland are regarded as the expression of chronic obstruction. b) Transoral stone extraction with marsupialisation of the duct under local anaesthetic in the same patient. c) Four months after the stone extraction, the patient is free of symptoms and has no new stones. The ultrasound scan shows a normal gland parenchyma (MMH: mylohyoid muscle, GSM LI: left submandibular gland). d) A neo-ostium with no signs of inflammation can be seen in the left posterior floor of the mouth.