A case-control study on chewing and smoking habits and oral submucous fibrosis (OSF) was undertaken in Karachi in 1989/90. Cases were patients detected with fibrous bands and leathery mucosa and hospital-based controls were matched by age and sex. Information on habits was collected by personal interview of 157 cases and 157 controls. Despite overall female preponderance, a substantial number of young men were enlisted. The male/female risks were found to be similar. Immigrants from India to Pakistan (Mohajir) had a similar risk status to local Punjabis. No differences between risks were found when comparing the three age categories, 21, 21-40, 41-60 yr. Among the cases, an increased risk was observed for areca nut chewing. This habit when practised alone appeared to have the highest risk (RR 154), followed by pan with or without tobacco (RR 64, 32 respectively). Logistic regression and discriminant analysis showed that daily consumption rates appeared to be more important with respect to risk than lifetime duration of habit. Tobacco habits were more prevalent amongst those 15 cases who presented with concurrent carcinoma and OSF: We conclude that areca nut chewing has a causal relationship with OSF: additional tobacco insult may be necessary for subsequent carcinoma development.

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Oral submucous fibrosis (OSF) is an oral precancerous condition characterized by symptoms such as intolerance to spicy food, altered salivation, progressive difficulty in opening the mouth, and signs like vesiculation, ulceration, blanching, rigidity, and stiffening of the oral mucosa and depapillation and altered mobility of the tongue. It is seen mostly among people of Indian subcontinent origin. The major structural change is extensive fibroelastic scarring of the lamina propria and deeper connective tissues. A combination of micronutrients (vitamins A, B complex, C, D, and E) and minerals (iron, calcium, copper, zinc, magnesium, and others) was evaluated for its efficacy in controlling the symptoms and signs of OSF in 117 compliant subjects in Karachi, Pakistan, in a single-arm preliminary study. The subjects received supplementation for one to three years. Significant improvement in symptoms, notably intolerance to spicy food, burning sensation, and mouth opening, was observed at exit. The interincisor distance deteriorated in 11 subjects (10%) at exit; it was stable in 56 subjects (49%) and improved in 48 (41%). The mean interincisor distance was 19.1 +/- 10.8 (SD) mm at exit compared with 16.2 +/- 7.5 mm at baseline. A significant proportion of concomitant lesions like leukoplakia also regressed at exit. The major outcome from this study was a beneficial clinical response in subjects with OSF to multiple micronutrient intervention, which justifies its further evaluation in well-designed randomized controlled trials in other settings in South Asia.