With the conventional 2D exam of clinical cases, the diagnosis is penalized by the lack of data, not only for vertical or transverse or asymmetrical problems, but for classical cases of anteroposterior dysharmonies. In these cases, the effectively used parameter, ANB angle, seems insufficient. So the authors elaborated a 3D biometry tool. The program of morphological analysis is able to deliver a complete description of dysharmony, supported by Cone Beam data capture. In the first part of this article the authors present the foundation of the model: anatomical reference, skeletal landmarks, teeth location by inertia matrix calculus, parameters, diagnosis and aid to treatment plan. The second part is the presentation, step by step, of the program in function, analyzing a great case of Class II hyperdivergent, border line surgery. All along the diagnosis way, the authors make the assistant discover all the documents given by the computer about complete 3D diagnosis and aid to treatment plan.

We could study Cone Beam documents of patients consulting in ORL with standard Angle Class I occlusion (45 ND), patients consulting in orthodontics with an orthodontic Class II (51 APNS) and patients with a surgical Class II (83 APS). The used 3D biometry calculates systematically a 164 set of parameters able to take into account all kinds of disharmonies; among which 38 parameters are specifically devoted to anterior-posterior \"off asymmetry\" pathologies. Then the specific Artificial Intelligence (AI) programs treat morphological data and give textual diagnoses. Analysis of the global sample aims to control the efficiency, separating different sub-samples one each other: t test appreciates efficiency of each parameter to recognize clinical sub-sample. The correlation coefficient, r, between each parameter and pseudo Angle molars Class II (GMMy-Gmmy) give the importance of its tie with Class II pathology. Presentation of parameters medium values in each sub-group gives the medium profiles. By direct comparison of patient\'s parameters values with medium profile, it is possible to locate patient\'s pathology. So we can take in account new parameters like arches upper/lower gap, anterior bases upper/lower gap, compensatingparameters... It is then possible to make more secure the clinical decision.