Background
➤ Saliva plays a crucial role in the maintenance of tooth integrity, food
and bacterial clearance, mechanical cleansing of the oral cavity, and
oral comfort. Saliva also provides antimicrobial activity preventing
oral infections and plays an important role in upper gastrointestinal
functions including taste perception, formation of food bolus, facilitation
of mastication, swallowing and speech, as well as lubrication of
oropharyngeal and upper esophageal mucosa. Thus, salivary gland
hypofunction is associated with an increased risk for oral infections,
carious destruction of teeth, dysgeusia, oral mucosal discomfort, and a
worsened nutritional state.
➤ Cancer patients may experience salivary gland hypofunction and
xerostomia as a consequence of cancer therapy. This is most notable
in head and neck cancer patients treated with external beam radiation
therapy. In this setting, salivary gland hypofunction and xerostomia may
be severe and permanent. This results in a profound, potentially life-long
adverse impact on oral health and oral health-related quality of life. While
radioactive iodine, total body irradiation, and high-dose chemotherapy
with hematopoietic stem cell transplantation as well as moderate-
dose chemotherapy for solid tumors may also cause salivary gland
hypofunction, in these settings function loss and associated symptoms
tend to be less severe and often less long-lasting.