Abstract: A system and method are taught for designing a change to a virtual dental model comprising: a virtual articulator representing a three dimensional model of a patient's upper and lower dental arches including data defining a constraint of motion between the upper and lower dental arches; a simulation analyzer to simulate the motion using the three dimensional model and analyze resulting contacts on portions of the upper and lower arches during the movement to provide contact data; and a designing module to design one of a virtual prosthesis for one of said upper and lower arches and a virtual desired dental modification using the contact data acquired from the simulation analyzer and the virtual articulator.