Periodontal Procedure Intensity and Incident Tinnitus in Korean Adults: A Nationwide Cohort Study

Background and Objectives: This study investigated the association between periodontal procedure intensity, serving as an indirect proxy for periodontal disease burden, and incident tinnitus in Korean adults. Materials and Methods: Using the Korean National Health Insurance Service-National Health Screening Cohort (2002-2019), we included adults aged ≥40 years who had a diagnosis of periodontal disease (International Classification of Diseases, 10th Revision [ICD-10] code K05), had undergone relevant periodontal treatment, and had available health-screening data. Because direct clinical periodontal measures were unavailable, participants were classified according to treatment intensity into: a mild procedure group (scaling or root planing only) and a moderate-to-severe procedure group (subgingival curettage, extraction, periodontal flap surgery, bone grafting, or guided tissue regeneration). Incident tinnitus was defined as an ICD-10 H93.1 diagnosis recorded during two or more outpatient visits to a neurology or otolaryngology department to improve diagnostic specificity. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models adjusted for demographic, socioeconomic, cardiometabolic, and behavioral factors. Results: Among 132,808 participants (76,844 mild; 55,964 moderate-to-severe), the incidence rate of tinnitus was higher in the moderate-to-severe group than in the mild group (4.38 vs. 3.87 per 1000 person-years). After adjustment, the moderate-to-severe group showed a significantly higher risk of tinnitus (HR 1.24, 95% CI 1.17-1.30). These associations were consistent across sex- and age-stratified analyses and in sensitivity analyses using stricter tinnitus definitions. Conclusions: Greater periodontal procedure intensity was associated with a modestly higher incidence of tinnitus in this nationwide cohort. Because procedure intensity serves only as an indirect surrogate for periodontal disease burden, and because auditory confounders and short-term procedure-related factors were unavailable, causality and a specific inflammatory mechanism cannot be established. Further studies incorporating direct periodontal measurements, audiological data, and prespecified lag-time analyses are warranted to confirm these findings.