The craniofacial region is one of the most complex regions of the human skeleton and is thus challenging to analyze. The frontal view of the face should be an integral part of facial evaluation, as man presents himself to the world face forward. Objective: The objective of this study was to investigate the existence of a transverse mandibular adaptation in the three sagittal skeletal malocclusions (SSM) by measuring the mandibular width at three different levels: Condylar superior (Csup), Antigonion (AG) and Mental foramen (MF), and the degree of divergence of the rami and the mandibular body using cone beam computed tomography (CBCT) scans and Dolphin imaging software. Material and Methods: CBCT scans of 90 individuals, aged between 18 and 40 years old, were divided into 3 equal groups according to their ANB: Class I (1≤ ANB <5), Class II (ANB ≥ 5) and Class III (ANB < 1). The same sample was also divided into another 3 groups according to the mandibular plane angle with SN as follows: Normodivergent facial type (27≤ MP/SN <37), hypodivergent facial type (MP/SN<27) and hyperdivergent facial type (MP/SN≥37). Landmarks were identified on the axial plane as well as on the three-dimensional reconstructed view, and then the distances and angles measured using the measurement tool of the Dolphin imaging software. Results: A statistical significant decrease in the intercondylar distance of Class II (CII) SSM compared to intercondylar distance of Class I (CI) and Class III (CIII) SSM’s. Mandibular width at the AG and at the ME landmarks was found to increase in CIII SSM in comparison with CI and CII SSM’s. Another characteristic is the decrease of the angle between the contralateral rami in CIII SSM compared to CI and CII SSM’s. An index was established for each SSM: The Total Transverse Mandibular Index (TTMI), by dividing the Transverse Vertical Mandibular Index (TVMI= AGR-AGL/CsupR-CsupL) over the Transverse Horizontal Mandibular Index (THMI=AGR-AGL/MFR-MFL). Conclusion: Mandibular width varies between the three SSM’s which dictates the use of the Transverse Mandibular Indices, additionally to the sagittal and vertical parameters, in orthodontic diagnosis. Keywords: Transverse mandibular morphology - Mandibular width - Cone beam computed tomography - Sagittal skeletal malocclusions.