Prevalence of oral mucosal normal variations and lesions in a middle-aged population: a Northern Finland Birth Cohort 1966 study.

In the middle-aged northern Finland population, 4% of OMLs were potentially malignant disorders, including OLR (2%), OLP (1.5%) and leukoplakia (0.5%). In particular, smoking and snuff use increased the risk for having any oral mucosa changes.