Salivary gland hypofunction (objective evidence of diminished salivary output) and xerostomia (the subjective sensation of dry mouth) are common conditions. Patients with
salivary gland hypofunction and altered saliva composition
are at increased risk for developing caries, oral fungal infections, oral mucosal changes and debilitating symptoms,
swallowing problems, and diminished or altered taste. The
most prominent cause of xerostomia and salivary gland hypofunction is the intake of medications interfering with the
nervous regulation of salivary secretion. Radiotherapy for
cancer in the head and neck region often leads to permanent
and severe xerostomia and salivary gland hypofunction due
to degeneration of the salivary gland tissue involved in the
radiation field. Sjögren’s syndrome, an autoimmune disease
affecting exocrine glands, causes permanent xerostomia and
hyposalivation due to immune-mediated structural changes
in the salivary glands. Ageing may also be associated with
structural changes in the salivary glands that can influence
the functions of saliva. This article reviews the aetiopathogenesis, clinical manifestations, diagnosis, and management
of conditions with salivary gland hypofunction, common salivary gland diseases (mucous cysts and sialoliths) and salivary gland tumours.