Oral cancer and mouthwash use.

The role of mouthwash and other factors was examined in relation to oral cavity cancer by means of a retrospective study. Daily use of mouthwash showed an excess risk in females but no excess risk in males. No dose response was seen in females with increased duration of use. In nonsmoking, nondrinking women as well, daily mouthwash use was associated with excess risk. Multiple logistic regression including all factors of interest showed inconsistent results for duration and frequency of mouthwash use. Due to the absence of a dose-response relationship and the possibility of confounding by tobacco and alcohol use, it was not possible to attribute causal significance to the association between daily mouthwash use and oral cancer in women.