Abstract: Method for fixation of different positions of a model (2) of the mandible relatively to a model (1) of the maxilla of a patient. One of the models consists of two members (15, 16) namely a tooth member and a socket member unified along coinsiding joint surfaces forming a common boarder plane (19) in a predetermined mutual position. The method comprises impressions of the teeth of the mandible and maxilla respectively are made in an index (54) in the shape of a plastically deformable plate, partly in a thick plate and partly in a thin plate. The mandible and maxilla models (2) are positioned in an articulator (5) so that they coinside with the thick index. The thick index is replaced with the thin index, forming an interspace between the joint surfaces of the divided model. The interspace is cast by filling the space with a cast mass, obtaining a removable interlayer plate.