Khat chewing, xerostomia, and unstimulated salivary flow among Yemeni adults: a cross-sectional comparative study using sialometry, the Clinical Oral Dryness Score (CODS), and the Summated Xerostomia Inventory (SXI-D)

Objectives To evaluate the association between khat chewing and oral dryness among Yemeni adults using clinical (Clinical Oral Dryness Score; CODS), symptom-based xerostomia assessment (Summated Xerostomia Inventory–Dutch Version; SXI-D), and unstimulated salivary flow rate (uSFR) outcomes. Materials and Methods In this clinic-based cross-sectional comparative study (n = 200), participants were classified as khat chewers (n = 171) or non-chewers (n = 29). CODS (1–10) and xerostomia symptoms (SXI-D; 5–15) were assessed at baseline. Unstimulated saliva was collected by the spitting method over 15 minutes, and uSFR (mL/min) was calculated. Among chewers, uSFR was additionally measured immediately before and after a typical khat session (paired assessment). Results Most participants had mild-to-moderate clinical dryness (CODS 1–3: 49.5%; CODS 4–6: 45.5%), with 5.0% classified as severe (CODS 7–10). Mean baseline uSFR was lower in chewers than non-chewers (0.387 vs 0.445 mL/min). Among chewers, mean uSFR decreased from 0.395 mL/min pre-session to 0.229 mL/min post-session (p < 0.001). Xerostomia symptoms were common; 39.5% reported a dry mouth on a single-item screen. Conclusions Khat chewing was associated with reduced unstimulated salivary flow and frequent oral dryness in this Yemeni adult cohort, and salivary flow decreased substantially after a typical chewing session. Clinical Relevance: Oral health providers in khat-prevalent settings should screen for xerostomia and counsel chewers on hydration, caries risk mitigation, and symptom management, especially following prolonged sessions.