What is considered a severe reduction in salivary flow caused by radiotherapy?

What is considered a severe reduction in salivary flow caused by radiotherapy?

• A. More than 0.5 ml/min
• B. Less than 0.1 ml/min
• C. About 0.3 ml/min
• D. About 1.0 ml/min

Answer: (B)

A severe reduction in salivary flow from radiotherapy is defined by an extremely low unstimulated (resting) saliva rate. When the resting flow falls below 0.1 mL/min, salivary production is profoundly reduced, leading to pronounced xerostomia and related complications. Normal unstimulated flow is around 0.3–0.4 mL/min, and stimulated flow is higher (roughly 1–3 mL/min). Values like 0.3 mL/min or about 1.0 mL/min indicate mild-to-moderate reduction or normal stimulated function, not the severe category.

A severe reduction in salivary flow from radiotherapy is defined by an extremely low unstimulated (resting) saliva rate. When the resting flow falls below 0.1 mL/min, salivary production is profoundly reduced, leading to pronounced xerostomia and related complications. Normal unstimulated flow is around 0.3–0.4 mL/min, and stimulated flow is higher (roughly 1–3 mL/min). Values like 0.3 mL/min or about 1.0 mL/min indicate mild-to-moderate reduction or normal stimulated function, not the severe category.