Table 2.
List of points, lines and angles used to analyze the mandibular position and morphology, as well as the position of lower incisors on the basis of the literature [21,22,23,24,25,26].
| Points/Lines/Angles | Description of Points/Lines/Angles |
|---|---|
| Point S | Sella—geometrical center of Sella turcica |
| Point N | Nasion—the most anterior point localized in the frontonasal suture |
| Point Go | Gonion—point localized at the intersection of mandibular line and line tangent to the posterior border of mandibular ramus |
| Point a | Articulare—point localized at the intersection of sphenoid bone base and the posterior part of condylar outline |
| Point Po | Porion—the most superior part of external acoustic opening |
| Point Or | Orbitale—the most inferior point localized in the lower margin of the orbit |
| Point A | Subspinale—the deepest point localized in the anterior outline of the maxilla, below the anterior nasal spine |
| Point B | Supramentale—the deepest point localized in the anterior outline of the mandible, above the pogonion |
| Wits | AO-BO—the distance between the perpendicular projection of points A and B onto the functional occlusal plane |
| Point Pg | Pogonion—the most prominent point localized in the osseous outline of mental tuberosity |
| NL line | Nasal line—line between anterior and posterior nasal spines |
| ML line | Mandibular line—line between gnathion and the lowest point localized in the masseteric tuberosity (also known as GoGn line) |
| FH line | Frankfort horizontal line—line between points: porion and orbitale |
| L1 line | Long axis of lower incisor—line which connects the incisal edge with the radiological apex of lower incisor |
| U1 line | Long axis of upper incisor—line which connects the incisal edge with the radiological apex of upper incisor |
| OcclMd | Mandibular occlusal plane—line which connects the anterior cusp tips of lower first molars with the incisal edges of the lower central incisors |
| SN line | Sella-nasion line—line of anterior cranial base, which connects points: nasion and sella |
| Sa line | Line which connects points: sella and articulare |
| aGo line | Line which connects points: articulare and gonion |
| NGo line | Line which connects points: nasion and gonion |
| NPg line | Line which connects points: nasion and pogonion |
| SNPg angle | Angle between SN line and NPg line |
| NL/ML angle | Angle between NL line and ML line |
| FMA angle | Angle between FH line and ML line |
| FMIA angle | Angle between FH line and long axis of lower incisor |
| IMPA angle | Angle between long axis of lower incisor and ML line |
| L1/U1 angle | Interincisal angle—angle between long axes of lower and upper incisors |
| L1/OcclMd angle | Angle between long axis of lower incisor and mandibular occlusal plane |
| NSa angle | Saddle angle—angle between SN line and Sa line |
| SaGo angle | Articular angle—angle between Sa line and aGo line |
| aGoGn angle | Gonial angle—angle between aGo line and GoGn line |
| aGoN angle | Upper gonial angle—angle between aGo line and NGo line |
| NGoGn angle | Lower gonial angle—angle between NGo line and GoGn line |