Dental age estimation over half a century has largely been determined by physical examination and use of orthopentograms. Different age assessment Demirjian and Levesque methods have been adopted for age determination. Age determination assessment via orthopentograms is based on calcification of roots, growth of mandible and underlying succedeneous tooth buds. Demirjian et al 1973, proposed 9 stages of tooth Mineralization for age determination. Age determination is necessary in fields of forensic, anthropology, pediatric dentistry and orthodontics. The fact that over a period of time dental wear, caries and different dental diseases are responsible for change in morphology and function of teeth which results in discrepancies between different methods of age estimation. Present study determines a relationship between assessment of age from OPGs by dentist and the chronological age of patient. Subjects were selected randomly of age series from 6-13 years (both male and female) from the radiology department of Dow University of Health Sciences, Karachi. Retained teeth were found to be only among 5% of the total population. 95% of the targeted sample, did not had any retained teeth. Similarly, missing teeth were also not very evident on the radiographs of these children. Based on the results of this study, most of the children had all teeth present in their radiographs regardless of gender and other demographic factors. The study also showed that if the deciduous predecessor is lost early, the eruption of permanent is delayed. Teeth on right side of the arch were found to be erupting before the teeth on left side. The study demonstrates significant relationship between chronological and dental age of patient and OPG as a limited diagnostic aid for age determination.