Table 1.
The abbreviations and definitions of the landmarks.
| Landmarks | Abbreviation | Definition |
|---|---|---|
| Coordinate system points | ||
| Nasion | N | The most anterior point of the nasal frontal suture |
| Right porion | Po-R | The uppermost point of right external auditory canal |
| Right orbitale | Or-R | The lowest point of the right infraorbital margin |
| Anterior nasal spine | ANS | The apex of the anterior nasal ridge |
| Basion | Ba | The midpoint of the anterior edge of foramen magnum |
| Single points | ||
| Sellar | S | The central point of the pituitary fossa |
| A | A | The most concave point of the bone between the point of anterior nasal ridge and the point of superior alveolar margin |
| B | B | The most concave point of the bone between the point of the inferior alveolar margin and the point of the anterior chin |
| Gnathion | Gn | The midpoint between the anterior point of chin and the submental point |
| Menton | Men | The lowest point of the chin |
| Ig | Ig | The apex of alveoli between lower central incisors |
| Paired points | ||
| Left gonion | Go-L | Posterior inferior point of left mandibular angle |
| Right gonion | Go-R | Posterior inferior point of right mandibular angle |
| Internal point of left condyle | Co-L | The uppermost point of the left condyle |
| Internal point of right condyle | Co-R | The uppermost point of the right condyle |
| External point of left condyle | CdML | The innermost point of the left condyle |
| External point of right condyle | CdMR | The innermost point of the right condyle |
| Anterior point of left condyle | CdAL | The most lateral point of the left condyle |
| Anterior point of right condyle | CdAR | The most lateral point of the right condyle |
| Posterior point of left condyle | CdPL | The last point of the left condyle |
| Posterior point of right condyle | CdPR | The last point of the right condyle |
| Apex of left coracoid process | Cc-L | The uppermost point of the left coracoid process |
| Apex of right coracoid process | Cc-R | The uppermost point of the right coracoid process |
| Left sigmoid notch | Sg-L | The lowest point of the left sigmoid notch |
| Right sigmoid notch | Sg-R | The lowest point of the right sigmoid notch |
| Left mandibular inflection | Ma-L | The most concave and outermost point between left anterior edge of ramus and mandibular body turning point |
| Right mandibular inflection | Ma-R | The most concave and outermost point between right anterior edge of ramus and mandibular body turning point |
| Left mental foramen | Mf-L | The lateral superior point of the left mental foramen on the anterior surface of the mandible |
| Right mental foramen | Mf-R | The lateral superior point of the right mental foramen on the anterior surface of the mandible |