Editing Sjögren's disease (section)

====Saliva flow tests====
Symptoms of dry mouth and dryness in the oral cavity are caused by the reduced production of saliva from the salivary glands ([[parotid gland]], [[submandibular gland]], and [[sublingual gland]]).
In unstimulated whole saliva flow collection, the person spits into a [[test tube]] every minute for approximately 15 minutes. A resultant collection of less than {{Convert|1.5|ml|abbr=on}} is considered a positive result.<ref name="Dr. J. Parks, Ancaster ON Canada">Dr. J. Parks, Ancaster ON Canada</ref>
<ref name="Fox, R. I 2005"/> In a stimulated saliva flow test the person sucks on a sugar-free sweet, whilst collecting saliva. An unstimulated salivary flow rate of 0.1 to 0.2 ml/min and a stimulated flow rate of 0.7 ml/min or less is considered to be abnormally low flow rates indicative of salivary gland hypofunction.<ref>{{cite web | url=https://ostrowon.usc.edu/salivary-gland-and-flow-exam/ | title=How to Perform a Salivary Gland and Salivary Flow Exam | date=15 June 2020 }}</ref>

Unstimulated saliva production reduces by 40 to 70% between the ages of 20 and 80 years, but stimulated saliva production is not affected.<ref>{{cite journal |last1=Lacombe |first1=Valentin |last2=Lacout |first2=Carole |last3=Lozac'h |first3=Pierre |last4=Ghali |first4=Alaa |last5=Gury |first5=Aline |last6=Lavigne |first6=Christian |last7=Urbanski |first7=Geoffrey |title=Unstimulated whole saliva flow for diagnosis of primary Sjögren's disease: time to revisit the threshold? |journal=Arthritis Research & Therapy |date=December 2020 |volume=22 |issue=1 |pages=38 |doi=10.1186/s13075-020-2132-3 |pmid=32093745 |pmc=7041275 |s2cid=211265587 |doi-access=free }}</ref>