How is hyposalivation diagnosed?

• A. Stimulated or resting salivary flow rate
• B. Only blood tests
• C. Radiographic imaging of salivary glands
• D. Muscle biopsy of tongue

Answer: (A)

Hyposalivation is diagnosed by measuring how much saliva the glands produce, using sialometry. This involves assessing both resting (unstimulated) saliva flow and stimulated saliva flow. Measuring both helps capture baseline secretion and the glands’ ability to respond to stimulation, which can be reduced in different ways depending on the cause.

In practice, saliva is collected over a defined period (often a few minutes) without stimulation to get the resting flow, and then under stimulation (for example, chewing or a safe gustatory cue) to get the stimulated flow. The rates are expressed as milliliters per minute and compared to reference values; flows below the normal thresholds indicate hyposalivation. It’s important to control factors like hydration, time of day, and medications because they can affect flow.

Blood tests, radiographic imaging, or muscle biopsy don’t measure saliva production directly, so they are not used to diagnose hyposalivation.