The aim of this study was to compare the accuracy and reliability of mandibular cephalometric measurements on conventional 2D lateral cephalograms and 3D CBCT scans from same 30 subjects into three groups: Group I manual tracings for 2Dlateral cephalogram, Group II On screen digitized 2D lateral cephalograms and Group III digital tracing for CBCT derived 3D lateral cephalograms. Nineteen mandibular cephalometric parameters (12 angular and 7 linear) were assessed. ANOVA and Post HOC-LSD test was applied and statistical analysis revealed nonsignificant difference between Group I & Group II. However, significant difference was found between 2D conventional lateral cephalograms and Digital tracing for CBCT derived 3D lateral cephalograms for four angular (GoG-SN, FMA, S-Ar-Go, IMPA) & one linear parameter r(Co-Gn). The results demonstrated that all evaluated methodologies are reliable and valid for scientific research, the method used in the lateral cephalograms from the CBCT proved the more accurate and reliable.
