Sialometry is a measure of saliva flow. Many different techniques have been devised, yet none are perfect. Four major saliva glands and innumerable minor salivary glands generate saliva. The parotid glands produce saliva with stimulation, such as eating, sucking on a lemon candy, chewing gum, or smelling a tasty meal. The submandibular glands produce saliva on a continuous basis and thus serve to keep your mouth moist even when you are not eating. The total amount of saliva in your mouth is a mixture of fluids generated from saliva glands but also from the crevices of your teeth. The following tests can measure saliva production:
1. Whole unstimulated saliva production. You will be asked to sit quietly, without talking or chewing, and spit any saliva that accumulates in the floor of your mouth into a pre-weighed tube . This test is generally done for a total of 5-15 minutes.
2. Stimulated whole saliva production. You will be asked to chew on a piece of paraffin or pre-weighed gauze for a period of 5-15 minutes, following which the accumulated saliva is measured, either by spitting into a preweighed tube or weighing the wet gauze pad.
3. Stimulated parotid saliva production. Special suction cups are placed over the two small openings in your mouth from which the saliva produced by your parotid glands is released. Saliva produced by your parotid glands is collected in preweighed tubes for a period of 5-15 minutes. A sour liquid (such as lemon juice) is applied to your tongue throughout the test to stimulate parotid saliva flow.
The amount of saliva flow varies considerably from individual to individual and correlates poorly with the sensation of a dry mouth. Abnormally low amounts of saliva production have been defined for each of the tests described above, but these do not necessarily indicate that a patient might have Sjogren’s syndrome or other disease affecting saliva production.