Method for preparing a physical plaster model

A computer system for generating a virtual model of teeth, comprising:

• a processor operably coupled to a computer readable storage medium comprising instructions which, when executed, cause the processor to:
• receive a virtual model of a patient's dentition including a virtual upper jaw member and a virtual lower jaw member respectively corresponding to at least a part of each upper and lower jaw of the patient's dentition;
• receive data representative of at least a spatial relationship between the upper and lower jaws in occlusion;
• and
• incorporate in the virtual model a virtual alignment arrangement configured to provide virtual occlusion alignment between the virtual upper and lower jaw members according to the spatial relationship, the virtual alignment arrangement comprising a first virtual alignment structure of the virtual upper jaw member that receives a second virtual alignment structure of the virtual lower jaw member or the virtual alignment arrangement comprises a first virtual alignment structure of the virtual lower jaw member that receives a second virtual alignment structure of the virtual upper jaw member, thereby defining an updated virtual model,
• wherein the first virtual alignment structure comprises a first plurality of virtual positioning reference components and the second virtual alignment structure comprises a second plurality of virtual positioning reference components, the first plurality of virtual positioning reference components configured to fit with the second plurality of virtual positioning reference components in order to yield proper occlusion alignment of the virtual upper and lower jaw members.