title: Evaluation of Salivary Nitric Oxide Levels in Smokers, Tobacco Chewers and Patients with Oral Lichenoid Reactions.
abstract: BACKGROUND
  Nitric oxide (NO), a free radical, acts as a signalling molecule affecting numerous physiological and pathological processes. Role of nitric oxide as a mediator in tobacco related habits and the resultant oral lichenoid reactions was assessed.
  
  
  OBJECTIVE
  The aim of the study is to evaluate and compare the salivary nitric oxide levels in normal patients with that of smokers, tobacco chewers and patients with oral lichenoid reactions.
  
  
  METHODS
  One hundred and twenty patients were enrolled in the study which included 30 healthy patients without any chronic inflammatory lesion and habit as controls (group I), 30 smokers without the habit of tobacco/betel nut chewing and any oral lesion (group II), 30 tobacco chewers without the habit of smoking and any oral lesion (group III) and 30 histologically confirmed cases of oral lichenoid reaction with the habit of tobacco usage (group IV). Saliva from these patients was collected and the nitrite concentration was assessed.
  
  
  RESULTS
  Our results concluded that there was highly significant increase in the nitric oxide levels in smokers, tobacco chewers and patients with oral lichenoid reactions compared to that of controls. Also, there was a significant increase in nitric oxide levels in patients with smoking associated oral lichenoid reactions in comparison with smokers and in patients with lichenoid reactions associated with tobacco chewing in comparison with tobacco chewers.
  
  
  CONCLUSIONS
  Estimation of salivary nitric oxide levels is a simple, non-invasive procedure and could be analysed to suggest the role of nitric oxide in the pathogenesis of these lesions. The increased activity of the enzyme may indicate that nitric oxide has a pathophysiological role in these lesions.
authors.affiliation: Senior Lecturer, Department of Oral Pathology, Meenakshi Ammal Dental College , Chennai, India .
authors.forename: S
authors.initials: S
authors.lastname: Preethi
authors.affiliation: Head of Department, Department of Oral Pathology, Faculty of Dentistry, Melaka Manipal Medical College , India .
authors.forename: Joy Idiculla
authors.initials: JI
authors.lastname: Jose
authors.affiliation: Head of the Department, Department of Oral Pathology, Meenakshi Ammal Dental College , Chennai, India .
authors.forename: B
authors.initials: B
authors.lastname: Sivapathasundharam
authors.affiliation: Reader, Department of Oral Pathology, Meenakshi Ammal Dental College , Chennai, India .
authors.forename: B
authors.initials: B
authors.lastname: Sabarinath
keywords: Betel nut; Lichen planus; Saliva; Smoking