Effect of salivary secretion with mouthguard use on seasonal allergic rhinitis symptom improvement

Abstract

ObjectivesIt was shown that mucosal immunity via salivary IgA may be related to the improvement of seasonal allergic rhinitis (SAR) symptoms, and improvement of SAR symptoms through saliva flow increase has been reported in patients using mouthguard (MG) in dental treatment. The purpose of this study was to analyze the effect of MG use on SAR symptom improvement and to clarify the role of saliva on SAR symptom development. MethodsWe recruited patients from the Kanagawa Dental University Hospital including 38 and 8 patients with SAR and non-SAR symptoms during two seasons from March 2017 to April 2018. We analyzed the saliva flow rate pre- and post-MG use and measured the amount of IgA and IgG4 in the saliva. We assessed the correlation between SAR symptoms and MG use. SAR symptoms were examined according to a specific clinical score. ResultsIt was revealed that salivary IgA concentration was significantly lower in SAR patients than in controls. SAR symptoms significantly improved with MG use. The saliva flow rate and IgA levels significantly increased with MG use, although the IgG4 levels did not change. ConclusionsMG use may be beneficial for improving the symptoms of SAR patients by increasing the IgA levels. Trial registrationUniversity Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR: UMIN000026428) on 6thMarch 2017.