Considering a point prevalence of up to 20% among adults, bruxism is a clinically significant phenomenon. It was the aim of the present work to systematically review the literature published until June 2007 in order to identify contributions on risk factors for bruxism in adults. Prerequisite for consideration were reported measures of risk assessment, such as odds ratios (OR). Seven relevant articles were found. Depending on the value of the OR and the position of the lower limit of the reported confidence interval (CI(LL)), we distinguished four risk groups (A to D). Three variables--severe stress experience; age between 25 and 44 years; age between 45 and 64 years--were grouped into category A (very strong indication for clinically relevant risk factor: OR >2; CI(LL) >2). Five variables fell into category B (strong indication for clinically relevant risk factor: OR >2; 1 <CI(LL) < or = 2). Category C (indication for risk factor: 1 < OR < or = 2; CI(LL) >1) was composed of 16 variables, while category D (possible indication for risk factor: 1 < OR < or = 2; CI(LL) < or = 1) embraced 11 variables. On the other hand, the presence of occlusal interferences was not a risk factor.