Xerostomia and oral health quality of life: Patterns across different occlusal status in older adults

Abstract

Purpose: This study aimed to investigate the association between xerostomia severity and oral health-related quality of life (OHRQoL) across various functional occlusal statuses among older adults.

Methods: This cross-sectional study recruited 202 outpatients (130 females and 72 males) from a dental university hospital in Japan. Assessments included the Summated Xerostomia Inventory (SXI) for xerostomia, Oral Health Impact Profile-14 (OHIP-14) questionnaire for OHRQoL, saliva collection, and functional occluding units (FOUs). Analyses included Mann-Whitney U tests and regression models. A directed acyclic graph was constructed to identify potential confounders and mediators and ensure appropriate adjustment in the regression models.

Results: The mean age of the participants was 73.7 (SD: 7.6) years, ranging from 60–89 years, and 64.4% were females. The median SXI score was 7 (IQR: 6-8), and 14.4% had a score of 10 or more. The participants with xerostomia had higher OHIP scores than those without xerostomia (median, 15 vs. 9; P = 0.003). Salivary flow measures were not associated with the OHIP scores. However, SXI and FOUs were associated with the OHIP scores in the regression analysis (R²=29.7%). The subgroup analysis revealed that participants with a more FOUs had a stronger association between xerostomia and OHRQoL.

Conclusions: Among the older adults in this study, those with xerostomia and fewer functional occlusions had poorer OHRQoL. The relationship between dry mouth symptoms and OHRQoL was particularly robust among patients with better functional occlusion, suggesting that xerostomia management deserves attention even in patients with well-maintained dentition.