| Na-A distance |
Perpendicular distance between point A to Nasion |
| Pog-Na distance |
Perpendicular distance from Pogonion to Na |
| SNA angle |
Sella-Nasion-Point A angle |
| U1-A distance |
Distance between the facial surface of upper incisor and a vertical line drawn through point A |
| L1-A distance |
Distance between the edge of the incisors and a line drawn from point A-Pog |
| Upper airway space |
Point on the posterior outline of the soft palate to the closest point on the pharyngeal wall |
| Lower airway space |
Point of intersection of the posterior border of the tongue and the inferior border of the mandible to the closest point on the posterior pharyngeal wall |
| Lower Anterior Facial Height(LAFH) |
Distance from ANS to Me |
| Mandibular length |
Distance between Co-Gn |
| Mid-face length |
Distance between Co-A point |
| Facial axial angle |
Formed by a line constructed from PTM to Gn and the line perpendicular to the N point |
| Mandibular plane angle |
Angle between the anatomic Frankfort horizontal plane and the line drawn along Go and Me |
| Maxillary and mandibular differentiation |
Relationship between the mandibular length and midfacial length (Co-Gn)_(Co-A) |
