Table 1 Landmark definition for use in reference system
From: United Reference Method for three-dimensional treatment evaluation
Landmark | Definition |
|---|---|
Right Sella and Left Sella (R- and L Sella) | Points in the center of the right and left 3D borders of the Hypophyseal fossa. Points are digitized semi-automatically through manual tracing of the right and left borders of the Hypophyseal fossa and then automatically digitized by the software. (Fig. 1) |
Semi-automated Constructed Sella (C-Sella) | A constructed semi-automated point that lies midway between right and left Sella. (Fig. 1) |
Porion (Po) | The most superior midpoint of each external acoustic meatus. |
Porion axis | A line passing between the two Porion points. (Fig. 2) |
Orbitale (Or) | The most inferior point of each infra-orbital rim. |
Mid-Orbitale | A point midway between the two Orbitale points. (Fig. 2) |
Right and Left Constructed Orbitale (C-Orbitale) | Points at the level of mid-Orbitale point superior-inferiorly (Z coordinate) and lies at equal distances medio-lateraly from the C-Sella point (X coordinate), in a parallel direction to the Porion axis (Y coordinates). (Fig. 2) |