This work set out to determine how oral-health–related knowledge, attitudes, and day-to-day practices (KAP) influence the oral-health-related quality of life (OHRQoL) of individuals diagnosed with type 2 diabetes mellitus (T2DM). Between July 2023 and July 2024, a cross-sectional investigation was carried out in primary health facilities across the West Bank. Using cluster sampling from three geographic zones, a convenience group of adults 40 years or older with confirmed T2DM was selected. Information was collected through a validated Arabic questionnaire that captured socio-demographic data, oral-health knowledge, attitudes, behaviors, and OHRQoL, using standardized tools such as the OHIP-14. Participants recorded a mean OHRQoL score of 17.84 ± 11.65 (possible range 0–50). The areas contributing most to poorer OHRQoL were psychological discomfort, social disability, and handicap. The most frequently mentioned oral problems were dry mouth (62.2%), loss of teeth (48.6%), and dental caries (46.1%). Knowledge scores averaged 6.53 ± 2.07 (range 1–10), attitudes 4.88 ± 1.65 (range 0–6), and practices 1.99 ± 1.02 (range 0–6). Spearman’s correlations showed significant positive relationships: practice with knowledge (ρ = 0.160, P = 0.000), practice with attitude (ρ = 0.171, P = 0.000), and knowledge with attitude (ρ = 0.238, P = 0.000). The final regression model indicated that stable employment, higher income, and favorable attitudes predicted better OHRQoL. Declines in OHRQoL, however, were linked to visiting the dentist due to pain, discussing diabetes-related oral issues with a dentist, lower ratings of general and oral health, lower schooling, lack of diabetes history, and long delays before obtaining HbA1c tests. The findings demonstrate that attitudes play a central role in supporting higher OHRQoL among people with T2DM, whereas socioeconomic challenges and limited access to care contribute to poorer outcomes. Although many participants possessed adequate knowledge, their oral-health practices remained insufficient. Incorporating oral-care components into diabetes management, improving service availability, and addressing social barriers are essential for improving quality of life in this group.
