Determining the Negative Factors Affecting the Quality of Life Related to Oral Health in People with a History of Drug Abuse

Introduction Drug abuse is strongly linked to poor oral health, which significantly impairs Oral Health-Related Quality of Life (OHRQoL). Individuals with substance use disorders often experience pain, functional limitations, and psychosocial distress due to neglected oral care and the biological effects of drugs. This study aimed to identify socio-demographic, behavioral, and drug-related factors associated with impaired OHRQoL among people with a history of drug abuse in Birjand, Iran. Methods A cross-sectional study was conducted with 114 clients from an addiction treatment center. Data were collected through face-to-face interviews and the validated Persian version of the OHIP-14 questionnaire. Impaired OHRQoL was defined as a total score above the sample median. Bivariate and multivariate Poisson regression analyses were performed to identify predictors, with results reported as Prevalence Ratios (PR) and 95% Confidence Intervals (CI). Results The median OHIP-14 score was 27, with 52.6% of participants classified as having impaired OHRQoL. Multivariate analysis revealed that four factors were independently associated with poorer OHRQoL such as age >45 years (adjusted PR =1.42; 95% CI: 1.08–1.87), illiteracy (adjusted PR = 1.38; 95% CI: 1.05–1.82), lack of dental floss use (adjusted PR = 1.71; 95% CI: 1.12–2.61), and early initiation of drug use (<25 years) (adjusted PR = 1.65; 95% CI: 1.10–2.48) (all p < 0.05). Oral hygiene was alarmingly poor, as 55.3% of the participants did not use a toothbrush, and 96.5% never used dental floss. Conclusion Impaired OHRQoL in this population is driven by modifiable behavioral and socio-demographic factors. Integrating oral health education, particularly interdental cleaning, and preventive dental services into addiction treatment programs could substantially improve the quality of life for this vulnerable group.