Table 1. Definition of the landmarks used to orient and prepare the 3D images before analysis (Urbanová, 2016).

Landmark	Bilateral	Determination	Description
Tragus (tr)	Yes	Manual	The most lateral point on the tragus
Exocanthion (ex)	Yes	Manual	Lateral canthus of the eye
Endocanthion (en)	Yes	Manual	Medial canthus of the eye
Pupil (p)	Yes	Automatic	The center of the eye, calculated as the midpoint between the endo- and exocanthion
Pronasale (prn)	No	Manual	Most anterior point on the midline of the nose
Cheilion (ch)	Yes	Manual	Lateral point on the labial commissure
Pupil reconstructed point (prp)	No	Automatic	Landmark that is automatically determined by averaging both end- and exocanthions