BACKGROUND Oral Sub Mucous Fibrosis (OSMF) is the most common precancerous lesion prevalent in Asian subcontinent and India. It raises concern among oral healthcare professionals because among all potentially malignant oral lesions and conditions, this precancerous condition has highest rates of malignant transformation. The aim of our study is to evaluate the prevalence of OSMF in habitual areca nut chewers among the patients attending the out-patient Department of Dentistry of Veer Surendra Sai Medical College and Hospital, Burla. METHODS This cross-sectional study was conducted in dental out-patient department of Veer Surendra Sai Medical College and Hospital, Burla for a period of 3 years (January 2015 - December 2017). Individuals with a clinical diagnosis of Oral Submucous Fibrosis according to WHO were included in the study, after obtaining an informed consent and approval of Hospital Ethical Committee. A total of 36000 patients were screened, out of which 457 were included in the study. Specialist examiners carried out all oral examinations who were accustomed with oral mucosal lesions found among the local population. A sterile mouth mirror and examination gloves were used for intraoral examination. On the basis of age group, habit duration, and type of habit, the study was carried out. Shapiro‑Wilk test was used for assessing data distribution and Chi‑square test for comparing the categorical data. RESULTS The prevalence of OSMF was found to be more common among males than females, with 99.14 % in males as compared with 0.87 % in females. Majority of the patients were in the age group of 15 - 25 years (213 patients out of 457) which accounted for 46.6 % with most them in Stage II (69.01 %). 49.23 % of patients had habit duration of 3 - 7 years (225 out of 457) with the majority of them in stage II (60.88 %). CONCLUSIONS Increased occurrence of OSMF among the general population in India may be attributed to the sale of areca nut products especially gutkha and pan masala in public is precisely being targeted for the younger generation. Primary healthcare professionals and dentists should also help to cessation of these habits among the public by participating in the programs targeted to this cause. KEYWORDS OSMF, Prevalence, Inter-Incisal Mouth Opening

BACKGROUND Oral submucous fibrosis (OSMF) is the most common precancerous lesion, prevalent mostly in South East Asia. The habit of betel nut or gutkha chewing is the main cause for this. There is a direct association between gutkha chewing habit and development of OSMF, the reason being exaggerated forces on the masseter muscle due to vigorous chewing for prolonged period of time. So, the present study was done to evaluate the thickness of masseter muscle in OSMF patients. METHODS A total of 25 subjects were included in the study from January 2015 to December 2017. 25 OSMF patients belonging to the age group of 25-50 years who attended the outpatient department of Veer Surendra Sai Medical College and Hospital, Burla, with masseteric hypertrophy and betelnut or gutkha chewing habit for more than 5 years, were included in the study. The computed tomography (CT) scans were obtained using Siemens Somatom Sensation 4-slice CT scanner. During the scanning period, the patients were asked to keep their mouth gently closed and relaxed. Axial sections of the CT scans were assessed for masseter muscles. The thickness of the muscle was calculated using image-analysing software and the measurements made were in millimeter (mm). Tabulation was done and statistical analysis was done using Mann-Whitney U test. RESULTS The thickness of masseter muscle of right side was found to be more than the left side in all patients except for one patient and the outcome was statistically significant with one tailed p value < 0.01. CONCLUSIONS The duration and frequency of the habit were found to be directly proportional to masseter muscle thickness and also with the clinical progression of the disease. Similarly, we also concluded from our study that there exists an association of masseter muscle hypertrophy with OSMF, and CT scan meas KEYWORDS OSMF, Masseter Muscle, CT Scan