RESUMEN
BACKGROUND: Oral submucous fibrosis (OSF) is a precancerous condition caused by use of the areca nut. The reported prevalence of OSF in Bhavnagar district during 1967 was 0.16%. We investigated whether the impression of an increase in the incidence of the disease was real. METHODS: A house-to-house survey was conducted in Bhavnagar district, Gujarat state. The use of areca nut-containing products and tobacco was assessed through an interviewer administered questionnaire. The oral examination was done by dentists. The diagnostic criteria for OSF was the presence of palpable fibrous bands. RESULTS: A total of 11,262 men and 10,590 women aged 15 years and older were interviewed for their tobacco habits. Among 5018 men who reported the use of tobacco or areca nut, 164 were diagnosed as suffering from OSF. All but four cases were diagnosed among 1786 current areca nut users (age-adjusted relative risk: 60.6). Areca nut was used mostly in mawa, a mixture of tobacco, lime and areca nut, and 10.9% of mawa users had OSF (age-adjusted relative risk: 75.6). The disease as well as areca nut use was concentrated (about 85%) in the lower (< 35 years) age group. CONCLUSIONS: An increase in the prevalence of OSF, especially in the lower age groups, directly attributable to the use of areca nut products was observed. This could lead to an increase in the incidence of oral cancer in the future.