NTRODUCTION Oral malignancies are debilitating disorders of the oral cavity. Etiopathogenesis of these disorders is multifactorial. The prognosis of these disorders depends upon early diagnosis and management. 1 Imbalances between the oxidant-antioxidant status have been implicated in the pathogenesis of premalignant and malignant lesions. The extent of oxidative damage caused by ROS directly depends on body antioxidant defense mechanism. 2 Superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) are the three major enzymatic antioxidant defense systems responsible for scavenging free radicals and nascent oxygen. 3 Antioxidant enzymes catalyze decomposition of ROS. Redox modulation is seen by distinctive changes in the activities of these enzyme systems in oxidative stress. Thus, an overall balance between production Access this article online Quick Response Code

NTRODUCTION Consumption of various tobacco products is since 600 AD. It is becoming an upcoming trend for today's world. It causes both premalignant lesions and conditions depending upon type of usage. Tobacco is the second major cause of death in the world. 1 The death toll from tobacco consumption is now 4.9 million people a year. If the present consumption pattern continues, the number of deaths will increase to 10 million by the year 2020. 2 Chewing, smoking, and consumption of alcoholic beverages have become a common social habit in India. Epidemiologic studies have demonstrated a wide variety in prevalence rates in oral lesions in different population due to various habits. 3 Tobacco habit is prevalent both in males and females however higher tendency in males as compare to females. Furthermore, the prevalence was higher among the rural population and those with no formal education. It has been reported that the oral mucosal disease may affect 25-50% of individuals having various habits, depending on the population studied. 4 It is available in smoking and smokeless tobacco. Cigarette smoking is more common in urban than rural area. It is available in different forms like pan, pan masala, khaini, mishri, zarda, mawa, supari. 5 Smokeless tobacco contains, arecanut, tobacco, catechu, slaked lime. It causes various lesions like Access this article online Quick Response Code