Epidemiologic studies of oral mucosal conditions--methodologic issues.

The methods used in the international English-language literature of epidemiologic investigations of oral mucosal conditions were reviewed. Methods used to study leukoplakia, lichen planus, recurrent herpes labialis, recurrent aphthous ulcers, geographic tongue and candidiasis are highlighted. In addition, studies of the full range of pathologies documented in a population were reviewed. The methodologic issues raised by the epidemiologic literature as well as those to be considered for future studies of oral mucosal conditions are presented. Emphasis is placed on study population selection, diagnostic criteria development, type and training of examiners, risk factor assessment and issues related to data collection, analysis and reporting.