Table 2 Landmarks and reference planes used in this study
Definition | |
|---|---|
Reference landmark | |
Subnasale (Sn) | The midpoint of the angle at the columella base where the lower border of the nasal septum and the surface of the upper lip meet |
Labrale superius (Ls) | The midpoint of the upper vermilion line |
Cupid bow point (CBP) | The most elevated point of the philtrum on the upper vermilion border line |
Labrale inferius (Li) | The midpoint of the lower vermilion line |
Lower lip bow point (LLBP) | The breakpoint on the lower vermilion border line |
Stomion (Stm) | The point at the midline of labial fissure between gently closed lips |
Rt. Lt Stomion (Stm) | The breakpoint on the labial fissure line between gently closed lips |
Cheilion (Ch) | The point located at each labial commissure |
Soft tissue B point (B') | The deepest point on the facial midline, between the lower lip and chin |
Lower incisor tip (L1) | The midpoint of the incisal edge of the right mandibular central incisor. |
Upper lip prominent (UP) | A line parallel to the passing Ls to Stm touched the outer most point on upper lip from lateral view |
Lower lip prominent (LP) | A line parallel to the passing Li to Stm touched the outer most point on upper lip from lateral view |
Reference planes | |
Horizontal plane | A plane constructed with the right orbitale, the right porion, and the left porion (Frankfort horizontal (FH) plane) |
Coronal plane | A plane constructed with the right frontozygomatic suture (FSZ) and left FZS, perpendicular to the FH plane |
Sagittal plane | A plane constructed with nasion, perpendicular to the FH and coronal planes |