Saliva in diagnostics- a useful screening tool

Salivary flow testing is also known as sialometry, which measures the flow rate of saliva. Saliva is mainly produced by the major salivary glands, viz. parotid, submandibular and sublingual glands. Salivary flow testing is usually included in the topodiagnostic methods of testing for facial nerve paresis or paralysis, and is a very sensitive early indicator of nerve damage because the flow is drastically reduced in the first 24 to 48 hours of nerve injury. This finding was earlier used to select patients for early facial nerve decompression but it is now well known that neuropraxia may cause such a temporary dysfunction of the nerve and does not reliably indicate the extent of the lesion. It has therefore been given up [1] , as have been the other topognostic tests, viz. Schirmer’s test and electrogustometry.