Salivary gland dysfunction refers to a state where saliva secreted from the salivary glands shows quantitative or qualitative changes from the norm. It can broadly be categorized into decreased secretion (hypofunction) and excessive secretion (hyperfunction).
Among these, sialorrhea (also known as hypersalivation or drooling), where salivary secretion increases pathologically due to glandular hyperfunction, can be classified into primary sialorrhea and secondary sialorrhea caused by other factors. While sialorrhea is less common in adults than hyposalivation (xerostomia), it can occur secondarily due to various underlying conditions.
Salivation is regulated through the fine control of the autonomic nervous system—comprising the sympathetic and parasympathetic systems—and the body's reflexes. Specifically, the parasympathetic nervous system plays a major role. Factors affecting this regulation are diverse, including oral movements like chewing, taste reflexes, and sensory stimuli such as smell, pain, and temperature, as well as psychological triggers.
