Sjögren's syndrome (SS) induces difficulty in chewing and swallowing due to low salivary flow. However, these symptoms may be associated with other factors, such as orofacial myofunctional disorders and temporomandibular disorder (TMD), which have not been comprehensively assessed in this population. The aims of this study were to investigate orofacial muscles and functions as well as the presence of TMD in patients with SS compared with a group without SS and to analyze whether the patients' experience of limitations in orofacial functioning is associated with the orofacial functional status and muscle pain related to TMD.
Women with SS based on the 2002 American-European Consensus Group criteria and volunteers paired by age and sex were compared. The examinations included the orofacial myofunctional evaluation with scores (OMES) protocol, tongue and lip strength measures, and electromyography of the masticatory muscles. TMD investigations included clinical examination, self-report of symptoms, and assessment according to the Jaw Functional Limitation Scale.
Patients with SS present with impaired muscle and orofacial functions based on lower scores of all categories of OMES (P < 0.0001), tongue strength (P = 0.0003-0.0004), and masticatory muscle activity (P = 0.0002-0.007), as well as worse TMD signs and symptoms (P < 0.05) and jaw functional limitation (P < 0.0001-0.0003).
Patients' experiences with limitation in mastication and swallowing were associated with orofacial myofunctional status and muscle pain related to TMD. Those disorders should be monitored along with disease control and must be addressed in the clinical evaluation to prevent nutritional and metabolic comorbidities in patients with SS.