Identification of the pattern of copper as an etiological factor in oral submucous fibrosis: a cytological study

Oral Submucous Fibrosis (OSF) is a well-recognized, potentially malignant disorder causing generalized fibrosis of the submucosal oral soft tissues. Though this disease is believed to be multi-factorial, areca nut chewing has emerged as the most important causative factor for OSF. Areca nut is known to have high levels of copper, which is believed to cause lysyl oxidase associated fibrosis.

To evaluate the pattern of copper in buccal mucosal cells of OSF patients, areca nut chewers and normal healthy individuals and to elicit the etiology of copper in OSF.

Patients were divided into three groups each comprising of 20 individuals- Healthy individuals (Group I); areca nut chewers without OSF (Group II); histopathologically confirmed OSF (Group Ill). The cytological smears made from each patient were stained with rhodanine stain for copper and evaluated for the qualitative and quantitative parameters of copper by using specific grading criteria.

Quantitative estimation of copper content showed a marked variation in the mean values. Mean value of group I was 0.11 ± 0.39; group II was 1.09 ± 0.81 and group III was 2.34 ± 0.74 (p<0.001). Mean values for qualitative estimation of copper were - 0.01 ± 0.36 for group I, 1.08 ± 0.82 for group II and 2.39 ± 0.72 for group III (p<0.001). Chi square analysis was used to assess the percentage distribution of copper granules. This revealed that the colour intensity and the number of granules were seen to maximum in OSF patients, areca nut chewers without OSF having intermediated values and normal healthy individuals having the least values.

An evident increase in the copper staining in group III individuals as compared to group I and group II was well appreciated. Increased copper levels in the local environment of the oral cavity indicates its role in lysyl oxidase associated submucosal fibrosis.