The identification of an unknown person by facial reconstruction, gender, and age determination is one of the duties of the forensic sciences. In some cases, the skull and mandible cannot be obtained together. In this case, facial reconstruction of the skull without a mandible becomes a serious problem. The aim of our study was to design the mandible suitable for the anatomic structure of the skull by first determining the age group and gender of the skull for skulls without mandible. Our study was carried out on 3D-CT images provided in Bursa Uludag University Radiology Department. Individuals were divided into five age groups considering tooth and bone development. Our study was conducted on 282 3D-BT images. Twenty-three variables on the mandible and 54 variables on the skull were examined. SPSS 20.0 was performed for the developing the regression formulas, discriminant function analysis, and descriptive and comparative statistics. Comparative and descriptive statistical findings between sexes and age groups are presented in tables. Discriminant function analyzes were performed for age group and gender determination. Regression formulas were developed for the redesign of the missing mandible suitable for the skull anatomy. We believe that our thesis will be useful for forensic scientists and anthropologists with the regression formulas that will design the mandible suitable for the anatomy of the skulls without the mandible and age group determination by discriminant analysis method with morphometric data.