###### Abstract  
Clinicians and researchers have used various methods to reproduce the maxillomandibular relationship and mandibular movement of individual patients using an articulator, with efforts being made to reduce errors associated with the conventional technique. When a change to a vertical dimension is required during the conventional prosthesis construction process, the maxillary and mandibular casts are mounted on the mechanical articulator using a facebow and bite registration and the elevation of the anterior guide pin of the articulator is used. However, this can inevitably cause errors due to differences between the articulator hinge movement and the actual trajectory of the patient. There has recently been increasing interest in tracking the trajectory of jaw motion of a patient, and this paper presents a new technique for altering the vertical dimension based on the measured trajectory. Target materials for performing tracking are attached to the maxillary and mandibular anterior teeth to record opening and closing movements of the patient's mouth in real time and align the patient's scanned intraoral data or cast data. The movements of the targets are replaced with the movement of the patient's oral scan data. Additionally, then the occlusal vertical dimension is set to a new position based on the obtained trajectory. After determining the optimal vertical dimension with consideration of the space required for restoration, maxillary and mandibular STL files are exported and the designed cast is created using a 3D printer. The printed cast is mounted on an articulator for subsequent procedures. This approach maintains the patient's actual maxillomandibular relationship at various vertical heights and can also reduce the chair time required when adjusting for errors. target tracking; digital dentistry; CAD-CAM; occlusal vertical dimension; maxill-mandibular relationship +
Footnote †: journal: Medical  
the vertical dimension for restorative material, enhancing the esthetic tooth display and allowing for re-establishment of physiologic occlusion [4]. When the orthodontic force is applied to the teeth, periodontal ligament and alveolar bone change occurs abruptly due to the biochemical adaptive response [5; 6]. Therefore, it is important to alter the vertical dimension as little as necessary after obtaining an accurate maxillomandibular relationship so that the residual teeth are not affected. Additionally, it is of paramount to mount the study casts in centric relation. In the traditional method, an impression acquisition process is used to create a plaster cast that reproduces the patient's oral condition, which records the maxillary position based on the patient's cranial base. A facebow and the check-bite in centric relation position are used to transfer the cast to the articulator. A temporary dental prosthesis is then fabricated based on the newly set vertical dimension by raising the incisal guide pin of the articulator [4]. However, for convenience, facebows are not based on the patient's true hinge axis points. In addition, since the patient may have a centric relation-maximum intercuspation (CR-MI) discrepancy, the difference in the positions of the maxilla and mandible may occur when the gypsum model is mounted on the articulator. Therefore, the position and the maxilla-to-mandible vertical dimension of the cast may differ from the patient's actual dimensions [7], and errors may accumulate in the prosthesis being constructed based on this position. Recent technological advances in digital dentistry have led to various methods for tracking jaw movement being proposed. A target-based method for tracking the movement of a specific reference point using an optical scanner is simpler than other tracking methods that involve mounting bulky and inconvenient equipment on the head, and has the additional advantage of recording the natural movements of patients [8; 9; 10].