Landmark | Description |
Alare (Al) | The most lateral points on the nasal aperture in a transverse plane. |
Anterior nasal spine (ANS) | The most anterior point at the sagittal plane on the bony hard palate. |
Basion (Ba) | The most inferior posterior point of the occipital bone at the anterior margin of the occipital foramen. |
Crista galli (Cg) | Most superior point on the crista galli. |
Ectoconchion (Ec) | The intersection of the most anterior surface of the lateral border of the orbit and a line bisecting the orbit along its long axis. |
Ectomolare (Ecm) | The most lateral point on the outer surface of the alveolar borders of the maxilla, often opposite the middle of the second molar tooth. |
Gnathion (Gn) | The midpoint between the most anterior and inferior points of the hard tissue chin in the midsagittal plane. |
Gonion (Go) | The most outward inferior point on the angle of the mandible. |
Inferior nasal aperture (IN) | Most inferior point on the inner cortex of the anterior nasal aperture. |
Menton (Me) | The most inferior midline point on the mandible. |
Nasion (N) | The point of intersection between the frontonasal suture and the midsagittal plane. |
Orbitale (Or) | The lowermost point in the lower margin of the bony orbit. |
Porion (Po) | The most superior point of the external auditory meatus. |
Pogonion (Pog) | The most prominent point in the chin. |
Sella (S) | The geometrical centre of the sella turcica. |
Subspinale (A) | The most concave point of anterior maxilla. |
Supraorbital notch (So) | Most superior point on the inner cortical plate of the orbital rim. |
Anatomical plane | Description |
Frankfurt horizontal | A line connecting the Po and Or points. |
Nasion-Pogonion | A line connecting the N and Pog points |
Sella-Nasion | A line connecting the Sella and the Nasion points. |