Insomnia and Risk of Tooth Wear and Fracture: Evidence From a Nationwide Population-Based Cohort

Insomnia is associated with various systemic conditions; however, its relationship with structural dental outcomes-particularly tooth wear and tooth fracture-has not been well defined.

To investigate the association between clinically diagnosed insomnia and the incidence of tooth wear and fracture in a nationwide population-based cohort.

Data were obtained from the Korean National Health Insurance Service-National Sample Cohort. Adults aged ≥ 20 years who underwent health screening between 2011 and 2014 were included. Insomnia was defined using the International Classification of Diseases, 10th Revision codes, and prescription records of hypnotics. Two separate cohorts were constructed for tooth wear and fracture outcomes. Individuals with prior diagnoses of bruxism, temporomandibular disorders, malignant neoplasms, certain psychiatric or neurological disorders, or insomnia during the washout period were excluded. Propensity score matching (1:3) was applied, and hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using the Cox proportional hazards models.

After matching, 81 096 participants were included in the tooth wear cohort and 82 256 in the tooth fracture cohort. Individuals with insomnia exhibited significantly higher incidence rates of tooth wear (29.02 vs. 26.27 per 1000 person-years; adjusted HR: 1.10, 95% CI: 1.06-1.15) and tooth fracture (16.70 vs. 13.63 per 1000 person-years; adjusted HR: 1.20, 95% CI: 1.13-1.26) than controls.

Clinically diagnosed insomnia was modestly but significantly associated with increased risks of tooth wear and fracture, underscoring the need for early oral health evaluation and coordinated care between dental and sleep medicine professionals.