Mandibular asymmetries called the longitudinal differences of right and left sides of the jaw with respect to midline, in three spatial planes. Objective: To determine the frequency of mandibular asymmetries in the three planes of space by Cone Beam Volumetric Tomographic Scanner (TCCB). Methods: We analized 40 records by Cone beam scans (New Tom 3G Cone beam Volumetric Tomographic Scanner) by simple random sampling of patients between 18 and 70 years obtained since 2011 to 2013 and taken with a large window that would display the complete mandibular bone. Axial slices were obtained from the lingula in cranio-caudal direction every 5 mm until the gonial angle. Results: 2.5% of the records showed moderate differences in the length of the mandibular body predominantly right. In amplitude was found the left branch predominantly. In the length of the ramus, 10% had moderate predominance of the right side. Conclusions: 1) Frequently asymmetries are at the thickness of the mandibular branches . 2) The degrees of Moderate to High differences occur more frequently at the thickness of the mandibular branches. 3) It is not possible to determinate proportionally the thickness of the mandibular branches only obtaining a 2D image.