Introduction Leukoplakia, erythroplakia, smoker's palate, and oral sub mucous fibrosis (OSMF) are potentially malignant precancerous conditions of the oral cavity which are thought to be intimately associated with the habit of chewing areca nut and tobacco either in the smoking or smokeless form.

Material and Methods A case control study was carried out in a representative North Indian population by organising oral health checkup camps. A validated questionnaire was administered to all subjects enrolled followed by their clinical examination. The suspected precancerous cases were confirmed by histopathological examination. Cases were defined on conformation of the biopsy report and matched with healthy controls. Univariate and multivariate analyses were performed and the ORs were calculated for the risk factors.

Results We found 448 cases of OSMF, 61 leukoplakia, 4 erythroplakia, 24 smokers palate and 17 oral lichen planus cases among 3136 subjects enrolled. Twelve cases confirmed as OSMF developed squamous cell carcinoma during the course of the study, however no such conversion is reported from other precancer groups till now. Strong correlation between the areca nut/tobacco products and oral precancerous lesions was observed. The OR ranged from 4.77 to 6.88 for areca nut users while for tobacco users it was 4.55–9.71, depending upon daily frequency of usage.

Conclusion The study revealed areca nut and tobacco as potential risk factors for the occurrence of oral precancer lesions.