The purpose of this research was to assess the accuracy of the Demirjian method for determining the chronological age of a sample of Egyptian children from the Delta region using the evaluation of seven permanent mandibular teeth in dental panoramic radiographs, and to create an age prediction formula appropriate for the population under study. In order to determine dental ages; 799 dental panoramic radiographs (DPTs) of children in good physical condition, aged 6 to 17 years were examined using the patient medical documentation who had previously visited Mansoura University Dental Hospital. This study was retrospective cross-sectional. The chronological ages ranged from six to seventeen years old with a mean 12.2 ± 2.7 years for girls and 12.3 ± 2.8 years for boys. Moreover, the mean dental ages were 11.9 ± 2.5 for girls and 12.2 ± 2.7 years for boys. The mean discrepancy between CA and EDA was 0.1004 in boys, and 0.3034 in girls. Girls were overestimated in many age groups (6-7), (7-8), (8-9), (9-10), (10-11) and (11-12) and for male groups (6-7), (7-8), (8-9), (11-12), (12-13), (13-14) were overestimated. A proposed algorithm for estimating dental ages was developed using linear regression. Demirjian's method might not be appropriate for Mansoura city's Egyptian children. An appropriate substitute would be the creation of a prediction equation to convert adjusted dental age into accurate chronological age adjusted for Egyptian children. It is necessary to test the newly created prediction equation on all Egyptian children.