Annex 1: 3D cephalometric analysis

The 3D cephalometric landmarks, 3D cephalometric planes and 3D cephalometric measurements used in the IPS CaseDesigner™ 3D cephalometric module have been modified by Swennen G. R. J., based on the definitions that can be found in specialized literature, such as:

Swennen G. R. J., Schutyser F., Hausamen J.-E. Three-Dimensional Cephalometry. New York, United States: Springer, 2006.

Swennen G. R. J. 3D Virtual Treatment Planning of Orthognathic Surgery. New York, United States: Springer, 2017.

Reyneke J. P. Essentials of Orthognathic Surgery. Hanover Park, Canada: Quintessence, 2010.

Arnett G. W., McLaughlin R. P. Facial and Dental Planning for Orthodontists and Oral Surgeons. New York, United States: Mosby, 2004.

By default, measurements in 3D cephalometric analysis are made with regard to the 3D PHP (planning head position) cephalometric reference system. The 3D PHP cephalometric reference system is defined in the Edit Natural Head Position wizard prior to surgical planning and consists of the following reference planes:

Horizontal plane: 3D PHP x-Pl

Median plane: 3D PHP z-Pl

Vertical plane: 3D PHP y-Pl

CB (Cranial Base) is the identification for cranial base-related measurements, meaning that the 3D Cephalometric Reference System is based on the Anterior Cranial Base (S-N), with the horizontal plane six degrees below the Sella-Nasion (S-N) line. The reference planes for cranial base-related measurements are:

Horizontal plane - 3D CB x-Pl: plane rotated six degrees clock-wise from the Anterior Cranial Base plane (rotation point Sella, rotated in the plane of the lateral cephalogram).

Median plane - 3D CB z-Pl: through the Sella-Nasion line and perpendicular to the Horizontal plane (3D CB x-Pl).

Vertical plane - 3D CB y-Pl: perpendicular to the Horizontal plane (3D CB x-Pl) and perpendicular to the Median plane (3D CB z-Pl) through the Sella.

Note

If the clinical situation differs from the theoretical definition, you must adjust the points in order to obtain an optimal result.

Where do you want to go

Cephalometric landmarks

Planes

Angular measurements

Distance measurements

Position measurements

Ratio measurements