Intricate relations and concepts of reference points in prosthodontics: A literature review

A Novel Technique to Align the Intraoral Scans to the Virtual Articulator and Set the Patient‐Specific Sagittal Condylar Inclination

“…The FH plane is the most common reference plane during the maxillary cast orientation, which has been assumed to be horizontal when the patient is in the natural head position 17 . It was used in this technique as the virtual articulator type was Bio‐art A7 Plus, which uses the FH plane as the reference plane, and the upper arm of the virtual articulator represents this reference plane when the incisal pin is set at zero 6,16 . Although the choice of the reference plane should be based on the type of the virtual articulator used in the dental CAD software, 6 most of the reference planes can be easily located on the patient's facial scan in the dental CAD software.…”

“…To perform an individual mounting of the intraoral scans, the spatial relationship between the upper arch and the arbitrary hinge axis of the patient must be first recorded with a virtual facebow, which necessitates a minimum of two posterior reference points and one anterior reference point 16,17 . Currently, several posterior reference points that represent the arbitrary hinge axis have been proposed, such as the Beyron point, Bergstrom's point, and Gysi's point 16 . Most of these points are located by measuring prescribed distances from the skin surface landmarks 16 .…”

“…Currently, several posterior reference points that represent the arbitrary hinge axis have been proposed, such as the Beyron point, Bergstrom's point, and Gysi's point 16 . Most of these points are located by measuring prescribed distances from the skin surface landmarks 16 . In this article, a facial scanner was used to transfer the facial anatomic landmarks to the virtual environment, and the Beyron point was selected, which is accurate enough to represent the hinge axis and can be easily located in the dental CAD software 16 .…”

A Full‐Digital Technique to Mount a Maxillary Arch Scan on a Virtual Articulator

“…In this demonstration, the Frankfort plane was used because the virtual articulator type was Bio‐art A7 Plus, which used orbitale as the third point of reference. In practice, the choice of reference plane should be based on the articulator system in the CAD software and the clinic's needs …”

“…To locate the rotation center of the mandible, Bergstrom's point was selected. It is an average hinge axis point that can be determined by the spherical insert of the external ear canal and Frankfort plane, which could be found on the 3D model constructed from CBCT.…”