Damage to salivary tissues by radiation decreases their ability to excrete saliva. This is supported by Olmos et al, who used salivary scintigraphy on both irradiated and non-irradiated patients and found that 84% of those irradiated had total or partial disturbance in both baseline and stimulated function. Of those treated with greater than 4500cGy, salivary excretion was almost invariably impaired. Xerostomia is the term for the dry mouth, which can result from this loss.