In the conventional workflow of prosthetic and restorative dentistry, facebow records are used to record the spatial relationship of the maxillary dental arch to some anatomic reference point or points, to then, when transferring this relationship to a mechanical articulator, orient the plaster cast of the maxillary dental arch in the same relationship to the opening axis of the articulator.

However, in the digital workflow of prosthetic and restorative dentistry, facebow records have been replaced by virtual facebow techniques. It should be noted that in the development of these virtual facebow techniques the members of this research group have been pioneers as they developed what can be considered the first virtual facebow technique. Since then, different virtual facebow techniques have been presented. Among these techniques it can be highlighted the last technique developed by the members of this research group, that is, the technique that consists in first aligning the digital impression of the maxillary dental arch with the 3D digital replica of the patient's face and then transferring it to the virtual articulator (figure 2), since this technique allows to obtain the so-called virtual patient.

However, the accuracy of these techniques has not been thoroughly analyzed. Therefore, the aim of this research line is to analyze the accuracy of the different virtual facebow techniques and to develop an optimal virtual facebow technique based on the results of the different analyses.

The progress made to date in this research line has been disseminated through articles published in scientific journals, communications presented at international congresses and patents.