Chemosensory Dysfunction, Oral Disorders and Oral Health-related Quality of Life in Patients With Primary Sjögren's Syndrome: Comparative Cross-sectional Study

Comparative Cross-sectional Study

Mirjana Šijan Gobeljić; Vera Milić; Nada Pejnović; Nemanja Damjanov


BMC Oral Health. 2020;20(187) 

In This Article


Sjögren's syndrome (SS) is a chronic, systemic, autoimmune disease with the prevalence between 0.05 and 1% in European population. Exocrine glands, especially salivary and lacrimal glands, are mainly affected leading to dryness of the mouth and/or eyes. Fatigue, joint and muscle pain are commonly present in patients with SS. Sjögren's syndrome can be further subclassified into primary disease (primary Sjögren syndrome, pSS) and secondary disease (secondary Sjögren syndrome, sSS), when it is associated with another connective tissue disease.[1]

SS is triggered in genetically predisposed individuals by environmental factors, such as infectious agents. The complex pathogenesis of SS is characterized by dysfunction of innate and adaptive immunity. . The hallmarks of SS are lymphocytic infiltration of the exocrine glands and the presence of circulating autoantibodies (anti-Ro/SS-A, anti-La/SS-B),[2] as well as autoantibodies directed against muscarinic acetylcholine type 3 receptors (M3R), which functionally inhibit salivary secretion.[3]

There is no cure for SS. Patients with SS receive mainly symptomatic treatment, which is why artificial tears and saliva are recommended as standard substitution therapy. Dental erosions, dental caries, mucosal infection, ulcers and oral candidiasis are commonly present in patients with SS; they are related to a decrease in salivary flow and the qualitative changes in saliva. Due to oral cavity dryness (xerostomia), chewing, swallowing, speech and sleep may be affected, resulting in impaired quality of life in patients with pSS.[4]

Chemosensory disorders have been reported in patients with pSS.[5,6] Chemosensory disorders, which include olfactory and gustatory dysfunction, could manifest as reduced ability, distortion or absence of the senses of taste and/or smell.[7,8] Many patients with chemosensory disorders experience a burning sensations or numbness in the mouth, especially in or on the tongue, the sensations that may originate in the gustatory nerve fibers.[9] Burning mouth syndrome (BMS) is defined as a burning sensation in the tongue (BST), or burning in some other mucosal membranes, which lasts for at least 4–6 months.[10] Patients with SS and patients with burning mouth syndrome (BMS) usually have similar oral complaints; however, these diseases have different etiology, pathogeneses, diagnostic criteria, and treatment.[11] Halitosis, (oral mal-odor, defined as an unpleasant breath odor of oral or extra-oral origin), is another common oral complaint that can be associated with low salivary secretion or chemosensory disorders in patients with pSS.[12] Dysgeusia, BST and halitosis are associated with impaired oral health-related quality of life (OHRQoL). However, no evidence has been found to clearly associate these oral complaints with saliva secretion rates in patients with pSS.[6,13]

Patients with primary Sjogren's syndrome (pSS), as well as the physicians who treat them, most frequently focus on dry mouth, dry eyes, fatigue, and joint and muscle pain as relevant signs and symptoms of pSS. Chemosensory dysfunction, oral disorders, burning sensations in the tongue (BST) and halitosis, which negatively affect oral health-related quality of life (OHRQoL), are commonly not recognized.. Moreover, the patients and some physicians are not aware of the fact that chemosensory dysfunction and oral disorders are directly related to pSS. The data regarding chemosensory dysfunction and oral disorders, burning sensations in the tongue and mouth in patients with pSS are limited. Therefore, it is of utmost importance to assess the impaired olfactory and gustatory functions as soon as oral disorders in patients with pSS occur.

Before being diagnosed with Sjögren's syndrome, patients with oral symptoms are initially examined by a dentist. It is of great importance that dental professionals immediately recognize the signs and symptoms of xerostomia and suspect that these patients may suffer from pSS. In order to prevent the development of chemosensory dysfunction and oral disorders, it is essential to provide patients with pSS with early and appropriate treatment. Management includes intense oral hygiene, prevention of oral infections and their treatment, the use of artificial saliva, as well as local and systematic stimulation of salivary secretion.[14] Good oral hygiene, daily dental care and regular dental check-ups are of utmost importance. In cases of dysgeusia and burning mouth disorder, tricyclic antidepressants and clonazepam can bring some relief, but these drugs could also cause additional mouth dryness in patients with pSS.[15] Topical anaesthetics like lidocaine gel are indicated for severe dysgeusia.[16] Artificial saliva may provide useful relief from xerostomia.[17] Additionally, strategies that capitalize on non-olfactory components of food flavor (altering food texture, primary taste qualities, temperature, and color) should be implemented to help maintain previous levels of food enjoyment. Foods and beverages that are salty, sweet, or those which can stimulate the trigeminal nerve (e.g. black or red pepper, carbonated drinks) could make the eating experience more pleasant. Enhancing the olfactory component of food flavor can also help patients with olfactory dysfunction to increase their food intake. These compensatory strategies may also expand dietary choices thus maintaining food enjoyment in addition to healthy eating habits.

The aim of this comparative cross-sectional study was to evaluate olfactory and gustatory function, burning sensation in the tongue (BST), halitosis, and OHRQoL in patients with primary Sjögren's syndrome and to compare these findings with those of age- and gender-matched healthy controls. The study hypothesis is that patients with pSS have impaired chemosensory function which has a negative impact on Oral Health-Related Quality Of Life.