Tooth extractions cause bacteraemia (1), but the degree of bacteraemia is associated with the indi- vidual’s immuno-inflammatory response and the bacteriological status. Bacteraemia following extractions is of a transient nature in otherwise healthy individuals. Extractions in children treated under general anaesthesia showed the duration of the bacteraemia to be <15 min after extraction (2). In surgical removal of third molars, an initially high level of bacteraemia has been observed inde- pendent of the oral health status (3). Positive bacterial blood cultures persisted for at least 15 min following extraction of 3–4 teeth. Among men with clinical cardiovascular disease, tooth loss and periodontitis were associated with approxi- mately 10% higher carotid plaque prevalence and intima-media thickness of the carotid arteries (4); this was not seen in women. Chlorhexidine mouth- wash administered 30 s before any tooth extraction reduced the level of bacteraemia to 2% within 1 h after extraction under general anaesthesia (5). These studies did not differentiate between causes of extractions. There has been a range of studies approaching the issue of association of oral infec- tions and CVD using varying study design (6). Most tooth extractions are attributed to infection but are also performed in cases of trauma and as part of an orthodontic treatment plan. This study explores whether the reason for extraction is associated with myocardial infarction (MI). Materials and methods The Oslo study cohort of men was first studied in 1972 ⁄ 73 (7). The main objective was to study Community Dent Oral Epidemiol 2011; 39: 393–397 All rights reserved Ó 2011 John Wiley & Sons A/S Association between tooth extraction due to infection and myocardial infarction Ha ˚ heim LL, Olsen I, Rønningen KS. Association between tooth extraction due to infection and myocardial infarction. Community Dent Oral Epidemiol 2011; 39: 393–397. Ó 2011 John Wiley & Sons A ⁄ S Abstract – Objective: To explore whether the association between tooth extraction and nonfatal myocardial infarction (MI) varies by reason for extraction. Methods: Men of the Oslo study of 1972 ⁄ 73 took part in the health survey in 2000 (n = 6530) then aged 48–77 years. The present analysis is a nested case–control study of the men with a self-reported history of MI as cases (n = 548) and randomly drawn controls (n = 625). Reasons for extraction (self- reported) were recorded as periodontal infections (marginal periodontitis) or apical infection of a single tooth, and these were grouped as infection due to extractions. Extractions due to trauma or other causes were grouped as noninfection extractions. Results: More men with a history of MI had extracted teeth than controls (92.7% versus 88.6%; P = 0.020). The prospective logistic regression analysis predicting nonfatal MI showed strength of association between infection extraction, no extraction, or noninfection extractions combined [odds ratio (OR) = 1.64; 95% confidence interval (CI): 1.24, 2.16] in adjusted analysis and crude analysis (OR = 1.73; 95% CI: 1.34, 2.23). Adjustment was made for known risk factors for MI and periodontitis in 1972 ⁄ 73, such as systolic blood pressure, smoking, total cholesterol, BMI, and education recorded in the 2000 screening. Conclusions: Extractions due to dental infections were associated with nonfatal MI in elderly men. Lise Lund Ha ˚heim 1,2 , Ingar Olsen 1 and Kjersti S. Rønningen 3 1 Institute of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway, 2 Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway, 3 Norwegian Institute of Public Health, Oslo, Norway Key words: infection; myocardial infarction; tooth extraction Lise Lund Ha ˚heim, Institute of Oral Biology, University of Oslo, Pb 1052 Blindern, N – 0316 Oslo, Norway Tel.: +47 90 11 33 98 Fax: +47 22 84 03 05 e-mail: a.l.haheim@odont.uio.no Submitted 26 May 2010; accepted 25 March 2011 doi: 10.1111/j.1600-0528.2011.00616.x 393