A method for creating a physical teeth model comprising: providing a virtual three dimensional image of a patient's dentition or part of it; and preparing a physical model of the jaws, based on information from said virtual 3D image, wherein said physical model is a positive model or a negative model from which a positive model can be produced, said model comprising two members (100, 102; 120, 122), one representing the upper jaw and the other the lower jaw, and both members are produced with markings or an alignment arrangement to permit proper occlusion alignment of the two members of said positive model, wherein the alignment arrangement includes a mounting arrangement for mounting said members on an articulator, wherein prior to preparing said two members (100, 102; 120, 122) the virtual 3D image is virtually combined with the articulator to define articulator-engagement portions of said members; or wherein the alignment arrangement includes one or more alignment reference components (124R, 126R) in each of the members of the model, the components in the two members corresponding to one another such that each component in one of said members can be aligned to fit with the corresponding component in the other of said members to yield proper alignment of the two members, wherein prior to preparing said two members (100, 102; 120, 122) said one or more alignment reference components (124R, 126R) are produced virtually. providing a virtual three dimensional image of a patient's dentition or part of it; and preparing a physical model of the jaws, based on information from said virtual 3D image, wherein said physical model is a positive model or a negative model from which a positive model can be produced, said model comprising two members (100, 102; 120, 122), one representing the upper jaw and the other the lower jaw, and both members are produced with markings or an alignment arrangement to permit proper occlusion alignment of the two members of said positive model, wherein the alignment arrangement includes a mounting arrangement for mounting said members on an articulator, wherein prior to preparing said two members (100, 102; 120, 122) the virtual 3D image is virtually combined with the articulator to define articulator-engagement portions of said members; or wherein the alignment arrangement includes one or more alignment reference components (124R, 126R) in each of the members of the model, the components in the two members corresponding to one another such that each component in one of said members can be aligned to fit with the corresponding component in the other of said members to yield proper alignment of the two members, wherein prior to preparing said two members (100, 102; 120, 122) said one or more alignment reference components (124R, 126R) are produced virtually. wherein the alignment arrangement includes a mounting arrangement for mounting said members on an articulator, wherein prior to preparing said two members (100, 102; 120, 122) the virtual 3D image is virtually combined with the articulator to define articulator-engagement portions of said members; or wherein the alignment arrangement includes one or more alignment reference components (124R, 126R) in each of the members of the model, the components in the two members corresponding to one another such that each component in one of said members can be aligned to fit with the corresponding component in the other of said members to yield proper alignment of the two members, wherein prior to preparing said two members (100, 102; 120, 122) said one or more alignment reference components (124R, 126R) are produced virtually.