Objective Previous findings refer to certain predisposing medical conditions that compound the risk of developing severe and potentially lethal acute odontogenic infections (OI). The objective of this study was to clarify this rationale and infection severity in general. Material and methods Records of patients aged >= 18 years requiring hospital care for deep OI were retrospectively investigated. The main outcome variable was need for intensive care unit (ICU) treatment. Additional outcome variable was occurrence of infection complications and/or distant infections. Several parameters describing patients' prior health and recent dental treatment were set as independent variables. Results Of the 303 acute OI patients included, 71 patients (23%) required treatment in the ICU, with no significant difference between previously healthy and patients with disease history. OIs originating from teeth in the mandible compared with maxilla had 7.8-fold risk (p = .007) for ICU treatment in binary logistic regression analyses. Elevated levels of infection parameters at hospital admission predicted further ICU stay. Infection complications and/or distant infections occurred in 7.6% of patients, of which septicaemia and pneumonia were the most common. The mortality rate was 0.3%. Infection complications and/or distant infections occurred significantly more often in smokers (p = .001) and in patients with excessive consumption of alcohol or drugs (p = .025), however smoking showed 3.5-folded independent risk for infection complications and/or distant infections (p = .008) in logistic regression. Conclusions Severe OIs often occur in previously healthy patients. Smokers in particular are prone to the most serious OIs.Peer reviewe
