Table 1.
Definition of cephalometric points and landmarks used in the study
| Landmark | Description |
|---|---|
| Pogonion (Pog) | Most anterior point of the mandibular symphysis |
| Gnathion (Gn) | Most anteroinferior point of the mandibular symphysis |
| Menton (Me) | Most inferior point of the mandibular symphysis midline |
| SNA | The angle between sella–nasion plane (SN) and nasion–point A line (NA). It indicates if the maxilla is normal, prognathic, or retrognathic |
| SNB | The angle between sella–nasion plane (SN) and nasion–point B line (NB). It indicates if the mandible is normal, prognathic, or retrognathic |
| ANB | The angle between nasion–point A line (NA) and nasion–point B line (NB). It indicates whether the skeletal relationship between the maxilla and mandible is a normal skeletal class I, II or III |
| FMA | Frankfort to mandibular plane angle. Indicates the amount of mandibular divergency. This angle is formed between the Frankfort horizontal plane as drawn from orbitale to porion intersected with the mandibular plane as drawn from gonion to menton |
| SN-GoMe | This represents the mandibular divergency to the anterior cranial base and is formed by projecting a plane from the sella–nasion line in correlation to a line drawn from Go point to Me point |
| U1-PP | The angle between the long axis of the most protruded maxillary incisor and the ANS-PNS (PP) line |
| L1-MP (IMPA) | The angle between the long axis of the most protruded mandibular incisor and the mandibular plane |
| Upper lip to E line | Line drawn from tip of the nose (pronasale) to the tip of the chin (soft tissue pogonion) in correlation with the upper lip |
| Lower lip to E line | Line drawn from tip of the nose (pronasale) to the tip of the chin (soft tissue pogonion) in correlation with the lower lip |
| Pog to N perp | Distance between the line soft tissue pogonion and a perpendicular line to Frankfort tangent to the soft tissue nasion |
| Pog–Pog’ | The soft tissue thickness of chin at level of pogonion was measured as the horizontal distance between pogonion (Pog) and soft tissue pogonion (Pog’) points |
| Gn–Gn’ | Soft tissue thickness of chin at level of gnathion was measured as the horizontal distance between gnathion (Gn) and soft tissue gnathion (Gn’) points |
| Me–Me’ | Soft tissue thickness of chin at level of menton was measured as the horizontal distance between menton (Me) and soft tissue menton (Me’) points |