The human body is constantly changing. Scientific evidence shows that alveolar bone undergoes changes after extraction. These changes continue as time of edentulousness progresses. These changes continue occurring even after prosthesis is inserted.Different methods for the assessment of alveolar bone height have been commonly used in practice out of which the panoramic radiograph is excellent for visualization of general structures of the face. The aim of this study is to compare the bone levels in dentate and edentate areas of the mandible with orthopantogram. A retrospective study done in the Department of Prosthodontics, Saveetha Dental College. Data was collected from a total of 86000 patients who visited Saveetha dental college between Jun,2019 to March,2020. Out of this, OPG of 40 patients in the age group of 35-50 years and who fell in Kennedy's Class 1 classification of mandible were retrieved for the study. The OPG was analysed in ImageJ software. The bone height was measured from the inferior border of the mandible and the crest of the ridge in edentulous areas; the inferior border of the mandible and the alveolar crest in the dentulous areas. The height was obtained in pixels from the software which was later converted into distance in millimeter (mm). The data obtained was tabulated in SPSS for windows, version 20. Paired t-test was done to determine difference in the bone levels of dentate and edentate regions.The paired samples t-test revealed statistically significant difference between dentate and edentate regions in both males (P=0.000) and females (P=0.000). The correlation between dentate and edentate regions for males and females was also statistically significant with P=0.011 and P=0.000 respectively. Pearson correlation was done between gender and difference in bone levels in dentate and edentate regions was not statistically significant with P=0.342. However, Pearson correlation was done between age and difference in bone levels in dentate and edentate regions was statistically significant with P=0.031. The present study was conducted to understand the correlation between bone levels in the dentate and edentate areas of patients with Kennedy's class 1 mandible. Within the limitations of this study, it can be concluded that there is significant difference in the bone levels of dentate and edentate areas in both male and female patients.