Effect of environmental tobacco smoke on oral pigmentation: A systematic review

BACKGROUND AND AIM: Oral pigmentation is a condition in which the color of oral mucosa such as gingival mucosa changes. Some exogenous and endogenous factors may lead to oral pigmentation. Secondhand smoke (SHS) or environmental tobacco smoke (ETS) is indirect smoking of an active smoker’s exhalation that can lead to cardiovascular, respiratory system, and some oral diseases. The aim of this review study is to assess the effect of SHS on oral pigmentation. METHODS: Data in this study were collected from PubMed, MEDLINE, and Scopus databases with the Medical Subject Headings (MeSH) keywords (Passive Smoking, Secondhand Smoke, Environmental Tobacco Smoke, Smoke Pollution, Involuntary Smoking, and Pigmentation) in the English language among the studies conducted in the period of 1990 to 2019. All records were imported into the EndNote software and duplicate articles were removed. The titles and abstracts of all records were pre-screened and among the articles remained, the relevant ones were selected for review based on the inclusion and exclusion criteria. To assess the quality of the studies, the Strengthening the Reporting Observational Studies in Epidemiology (STROBE) checklist was used. RESULTS: Based on the STROBE checklist, the quality of the studies was assessed and finally, seven studies were included in the review, with six of them conducted about children and young adults and one about women. 6 (85.7%) articles showed a strong correlation between ETS and oral pigmentation and 1 (14.2%) showed no correlation. CONCLUSION: ETS probably was correlated to the oral pigmentation.