Unlike severe periodontitis, caries does not associate with intracranial aneurysms or aneurysmal subarachnoid hemorrhage

PURPOSE: Periodontal diseases and caries are common oral diseases that predispose to tooth loss if untreated. In this study, we investigated whether loss of teeth or caries associate with intracranial aneurysm (IA) pathology similar to periodontal diseases. METHODS: A total of 166 patients with either IA or aneurysmal subarachnoid hemorrhage (aSAH) underwent oral examination in Kuopio University Hospital and Tampere University Hospital. Findings were compared to geographically matched controls acquired from cross-sectional Health2000 survey. This study consisted of three sequential steps. First, we compared the number of missing teeth and prevalence of caries in IA and aSAH patients and geographically matched control population, second step was a multivariate analysis including other risk factors, and third step was a 13-year follow-up of the Health2000 survey participants with missing teeth or caries at baseline. RESULTS: Loss of teeth did not significantly differ between IA patients and controls. In logistic regression model adjusted for known risk factors and demographic data, 1–4 caries lesions (OR: 0.40 95%Cl 0.2–0.9, p = 0.031) was associated with lack of IAs, while age (OR: 1.03 95%Cl 1.01.1 p = 0.024), current smoking (OR: 2.7 95%Cl 1.4–5.1, p = 0.003), and severe periodontitis (OR: 5.99 95%Cl 2.6–13.8, p < 0.001) associated to IA formation. In the cox-regression, severe periodontitis at baseline increased the risk of aSAH (HR: 14.3, 95%Cl 1.5–135.9, p = 0.020) during a 13-year follow-up, while caries or missing teeth did not. CONCLUSION: Unlike severe periodontitis, caries does not increase the risk of IAs and aSAHs. However, cariogenic bacteria may participate to IA pathology by disseminating to circulation via inflamed gingival tissue. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00701-022-05406-4.