Background and Objectives: Xerostomia is common among institutionalized older adults, but the relative contributions of comorbidity burden and medication-class burden remain incompletely clarified. This study evaluated their associations with Xerostomia Inventory (XI) severity and explored related salivary dysfunction and clinical oral health findings. Materials and Methods: We conducted a cross-sectional study of 90 institutionalized older adults in Bucharest, Romania. Xerostomia Inventory (XI) scores, a binary dry-mouth question, chairside salivary assessments, comorbidity categories, medication classes, oral mucosal findings, and complete denture retention and stability were recorded. Primary analyses used hierarchical regression and bootstrap statistical decomposition; secondary and exploratory analyses evaluated salivary concordance, medication classes, denture-related findings, and oral mucosal conditions. Results: Medication-class count remained associated with XI severity after adjustment for comorbidity burden (partial r = 0.445, p < 0.001), whereas the association between comorbidity burden and XI was no longer significant after adjustment for medication-class count (partial r = −0.063, p = 0.557). Inclusion of medication-class count increased the explained variance in XI scores (ΔR² = 0.253, p < 0.001). Bootstrap decomposition yielded similar findings, with a significant indirect estimate and a non-significant direct estimate. Among complete denture wearers, XI severity was associated with maxillary denture instability (ρ = −0.687, n = 44). Conclusions: In this cohort, medication-class burden showed the strongest association with xerostomia severity, whereas comorbidity burden was not independently associated after adjustment. Given the cross-sectional design, these findings should be interpreted as exploratory associations and support future prospective studies integrating medication review with geriatric-prosthodontic assessment.

Background/Objectives: In institutionalized older adults, we examined the concordance between self-reported xerostomia and chairside salivary dysfunction and explored whether a smaller subset of Xerostomia Inventory items could retain comparable screening performance. Methods: This cross-sectional study included institutionalized older adults. The 11-item Xerostomia Inventory was compared with a six-marker chairside whole-saliva panel, with all variables scaled 0 (normal) to 1 (pathological). We measured how closely symptoms tracked each objective marker, how well the questionnaire identified hyposalivation, and whether fewer questions could be comparable with the full 11-item inventory. Results: The study included 90 participants, with a mean age of 79.5 years; 55.6% were women. Symptoms tracked every marker in the expected direction (correlation τ-b 0.32 to 0.62). The questionnaire identified objective hyposalivation with an area under the ROC curve of 0.87 (95% CI 0.78–0.96) and substantial chance-corrected agreement (Cohen’s κ 0.69, 95% CI 0.51–0.87). A five-item short form reproduced the objective findings as well as the full questionnaire did (cross-validated R² 0.56 ± 0.03 versus 0.56). Conclusions: In this high-prevalence institutional cohort, self-reported symptoms agreed with graded salivary function more closely than the older discordance literature would suggest, though still within the range of recent studies rather than beyond it. A five-item subset, chosen for its alignment with the objective salivary axis rather than for internal consistency, recovered as much as the full inventory, which points to a short, function-oriented score as a plausible first-stage screen. We would treat this short form as a candidate first-stage screening approach that requires external validation, rather than as a replacement for objective salivary assessment or as a validated replacement for the Xerostomia Inventory.