Epidemiology of Sjögren’s Syndrome—from an Oral Perspective

Abstract

Oral symptoms are among the most distressing manifestations for patients with Sjögren’s syndrome (SS). The feeling of dry mouth is unpleasant, and hyposalivation may contribute to difficulty in speaking, chewing and swallowing and reduced quality of life. Reduced salivary flow increases the risk for dental caries and problems with prosthetic replacement. It seems that SS is not as frequently occurring as previously anticipated. Population-based prevalence studies on primary SS in Europe, conducted on large background populations and in accordance with the AECG criteria, reported of a prevalence of 1–9 cases per 10,000 people. This gives a combined prevalence of nearly 39/100,000 (~0.04 %). The cause of Sjögren’s syndrome is even now not fully understood, and the treatment of oral symptoms is still mostly palliative. Hopefully, useful information will appear from the new methods that are now available for genome wide association studies, epigenetics, DNA methylation studies, and proteomics. Similarly, this is anticipated for the immunological side of the story. The interferon signature, the interferon γ/interferon α mRNA ratio, and CXCL13 are among the proposed biomarkers of active disease. In this review, we provide an update on oral aspects of Sjögren’s syndrome with emphasis on the latest publications on these topics.

The Utility of Major Salivary Gland Ultrasonographic Parameters in the Diagnosis of Sjögren Syndrome

“…B-cell hyperactivity represents a key hallmark of the pSS activity, reflecting in hypergammaglobulinemia, autoantibody production, and systemic manifestations of this disease. Serum beta-2-microglobulin is a biomarker of the lymphocyte hyperactivity [19]. This study revealed that the pSS patients presented higher values of serum beta-2-microglobulin than controls (2:84 ± 0:55 mg/l vs. 1:86 ± 0:44 mg/l, p < 0:0001).…”

“…Sjögren's syndrome, a complex autoimmune disease, is characterized by a broad spectrum of clinical and serological manifestations, dry eyes and dry mouth being the most common complaints [19].…”

Accuracy of a questionnaire on xerostomia as a screening tool for hyposalivation

“…Diverse external factors and natural alterations can lead reduced salivary flow 1,2 . This condition is known as hyposalivation 3,4 and affected individuals may or may not have a sensation of 'dry mouth', known as xerostomia 2,[5][6][7] . Both hyposalivation and xerostomia are conditions that can occur in an isolated manner, but xerostomia is most often the result of a reduction in salivary secretion and is therefore a strong indicator of hyposalivation [8][9][10] .…”

“…The causes of hyposalivation and xerostomia range from momentary factors, such as stress and anxiety [10][11][12] , to autoimmune diseases and chronic conditions, such as rheumatoid arthritis 13 , Parkinson's disease 13,14 , Sj€ ogren's syndrome 10,15,16 and diabetes mellitus [17][18][19][20][21] . The two conditions may also be found in patients requiring treatment for head and neck cancer 3,6,13,14,21 and those with diseases specific to the salivary glands 1,19 . Moreover, one of the major causes of reduced salivary flow is the use of particular medications 14,16,20,22 .…”

“…Hyposalivation is diagnosed using sialometry, which consists of collecting saliva to measure the amount of secretion produced per minute 12,18 . The diagnosis of hyposalivation is necessary, because this condition can exert a negative impact on activities of daily living and quality of life 3,13,17,23 . Another consequence of hyposalivation is a higher frequency of oral infectious diseases/conditions, such as caries, candidiasis, etc.…”