Salivary gland stone also known as salivary duct stone is a calcified structure which could be formed in the salivary gland or duct and block the flow of saliva in the mouth. Most of the stones affect the submandibular glands which are located at the floor of the mouth.
In fewer cases, the stones tend to affect the parotid glands which are on the inside of the cheeks or the sublingual glands that are under the tongue and several people with the condition suffer from multiple stones. These stones tend to form when the chemicals in the saliva gets accumulated in the duct or gland which contain mostly calcium.
Though the cause of this condition is not known, factors contributing to less saliva production and/or thickened saliva could be the cause for salivary stones. These factors include poor eating, dehydration as well as the consumption of certain medications together with blood pressure drugs and psychiatric drugs. Besides this, trauma to the salivary glands could also contribute to the risk of salivary glands.
The stones at the time of formation do not cause any symptoms though if they tend to reach a certain size which may block the duct, saliva goes back into the glands causing pain as well as swelling. The person may experience pain on an off which may gradually worsen with time. Inflammation and infection within the affected gland could also take place.
Some of the symptoms experienced include dull pain over the affected gland, swelling of the gland which could flare up and down, infection of the gland causing severe pain and the formation of an abscess and a feeling of being sick. The person will also experience intense pain and swelling after eating. If the salivary gland is blocked completely, one would feel sudden and intense pain once they start eating their meal which is followed by swelling and eases after a meal.
The physician could diagnose the stone on examining the mouth or through x-ray. If the stone is not seen through x-ray, one of the following scans may be needed: A computerized tomography - CT scan is done wherein x-rays and computer to create detailed images of the inside of the head and neck area is used.
A magnetic resonance imaging –MRI scan using strong magnetic field and radio waves to produce detailed images is done, Sialograph, a dye injected in the gland before an x-ray is taken and sialendoscopy, where a thin tube with a tiny light with camera at one end is inserted into the duct to enable the doctor to see the gland. Should a stone be visible, it can be removed at the same time.
The physician could also remove the stone by probing the salivary duct with a thin blunt instrument and if this does not seem to work, a procedure known as therapeutic sialendoscopy is done wherein a local anaesthetic is given to numb the mouth and a very thin endoscope is pushed into the duct .If a stone is seen the tiny instrument at the end of the tube is used to grip the stone and pull it out.
If the stone seems to be large, it may have to be broken up by using shock wave treatment where ultrasound waves are directed at the stone in order to break it up. This is known as extracorporeal shock wave lithotripsy. Earlier the procedure of removing salivary stone was done by making a small incision in the mouth but such an operation is rarely done in present times.