Dr.K.O.Paulose FRCS DLO, Consultant ENT Surgeon, Jubilee Hospital, Trivandrum, Kerala, India
Submandibular Gland Calculi
The formation of stones, or calculi, may occur throughout the body, including the gallbladder, urinary tract, and salivary glands.
Salivary gland stones are the most common disease of salivary glands. Salivary gland stones (calculi) are the commonest intraluminal cause of recurrent salivary gland swelling. Salivary stone occasionally forms in a salivary gland or duct, usually by deposition of calcium salts around a nidus of organic material, and has a layered microscopic structure.
About salivary glands
The salivary glands make saliva. Saliva is important in the breaking down of the food that you eat. It makes food moist, lubricating it as it passes from the mouth to the stomach. It also contains enzymes which break down some of the starch and fat in your food.
There are three pairs of glands that make saliva. The submandibular glands are under the floor of your mouth – one on each side – and drain saliva up into the floor of your mouth. The parotid glands lie just below and in front of your ears. Saliva passes down the parotid duct into the inside of your cheeks. The sublingual glands are just beneath your tongue.
You make small amounts of saliva all the time to keep your mouth moist. When you eat, you normally make much more saliva which pours into your mouth.
About Salivary Gland Stones
A salivary gland stone is sometimes called a sialolith or a salivary calculus. Most salivary stones are mainly made of calcium. However, there is no abnormality of the blood calcium level or any other problem with calcium in your body. Salivary gland stones are not usually associated with any other diseases. The size of the stone can vary from less than 1 mm to a few cm in diameter.
Why Stones are more in SM gland
Submandibular calculi are more common as its saliva is more alkaline, and has an increased concentration of calcium and phosphate. The saliva here has a higher mucous content than saliva of the parotid and sublingual glands. In addition, the submandibular duct is longer and the gland has an antigravity flow when compared with parotid gland.
When saliva cannot exit a blocked duct, it backs up into the gland, causing pain and swelling of the gland. The most common symptoms are pain and swelling of the affected gland at mealtimes. This occurs if the stone completely blocks a duct. The pain can be sudden and intense just after starting a meal. Swelling soon follows. The pain and swelling ease over about 1-2 hours after a meal.
However, most stones do not block a duct completely. A stone may only partially block saliva flow or not block the flow at all if it is embedded in the body of the gland. In these situations the symptoms can vary and include one or more of the following:
• Dull pain from time to time over the affected gland.
• Swelling of the gland. Swelling may be persistent or vary in size from time to time.
• Infection of the gland may occur causing redness and pain. This may develop into an abscess.
An ordinary X-ray test can detect and show the position of the stones. No further tests are then needed. A CT scan, ultrasound scan, sialogram can all be of use.
Most stones that cause symptoms will not go away unless they come out or are removed. Sometimes a small stone comes out into the mouth by itself. If that does not occur, possible treatment options and procedures include the following:
• Gentle probing into the duct from inside the mouth with a thin blunt instrument can sometimes free a stone which then falls into the mouth.
• A small operation to cut out the stone is the traditional treatment, described below.
• Shock wave treatment (lithotripsy) may be an option. This uses ultrasound waves to break up stones. The broken fragments then pass out along the duct. This is a relatively new treatment for salivary stones (although it has been used for many years to treat kidney stones). However, it is not satisfactory as the broken stones cannot be easily removed.
Surgical procedure: (described in the next video clip)