Sialometry: aspects of clinical interest

Whole saliva is a multiglandular secretion complex consisting of gingival fluid, desquamated epithelial cells, microorganisms, products of bacterial metabolism, food debris, leukocytes mucus from the nasal cavity and the pharynx. Saliva has many functions, including tissue repair, tamponage, protection, digestion, taste, antimicrobial action, maintaining tooth integrity and antioxidant defense system. A decrease in salivary flow (hyposalivation) is a common disorder and it is estimated that approximately 20% of the general population have this alteration. Hyposalivation may be due to diabetes mellitus, hypothyroidism, dehydration, impaired glandular parenchyma by infectious processes, granulomatous diseases or autoimmune and inflammatory conditions (such as Sjogren's syndrome and rheumatoid arthritis), radiotherapy of head and/or neck region, or it may be associated with mood disorders, adverse effects caused by the use of some medications or even be idiopathic. Conventional therapies for the treatment of reduced saliva flow with the use of chemical and gustatory secretagogues are still limited. However, new alternatives have shown great perspective in the treatment of this disorder. To diagnose a patient as having chronic hyposalivation is a challenge in clinical practice and methods of salivary flow assessment are little known by rheumatologists. The serial evaluation of salivary flow is important for the diagnosis and prognosis of certain oral and systemic conditions. This review addresses some aspects related to the role of saliva, the consequences of hyposalivation and methods of salivary flow rate measurement, useful concepts in the daily practice of rheumatology.