Clinical features :
- Adults are mainly affected
- Males twice as often as females
- Calculi are usually unilateral
- The classical symptom is pain when the smell or taste of food stimulates salivary secretion.
- Alternatively, duct obstruction can lead to infection, pain and swelling of the gland.
- Occasionally there are no symptoms until the stone passes forward and can be palpated in the duct or seen at the duct orifice .
- Alternatively, the stone may be seen in a radiograph.
- However, about 40% of parotid and 20% of submandibular stones are not radiopaque, and sialography may be needed to locate them.
- Calculi are not a cause of dry mouth.
Salivary calculi usually form by deposition of calcium salts around a nidus of organic material, and have a layered structure.
The roughness of their surface may cause the duct lining to undergo squamous metaplasia .
If sufficiently far forward in the duct, a stone may sometimes be milked forward and manipulated out of the orifice. Otherwise the duct has to be opened. An incision, usually under local anaesthesia, is made along the line of the duct just long enough to release the mass. A temporary suture should be put through the duct behind the calculus to prevent it from slipping backwards.
The papilla should be left unsutured or the margins of the opening are sutured to the mucosa on either side to prevent subsequent scarring or fibrous obstruction. If the gland has become damaged by recurrent infection and fibrosis, or calculi have formed within the gland itself, it may have to be excised.