Fig. 1

a Landmark placements on the face and b measurements of length (solid lines) and width (dotted lines) taken between the landmarks. Landmarks definitions according to the AATCC14-2020. Sellion (S) (The most posterior midsagittal point on the nasal root at the top of the nasal bridge), P (1/3 of the nose length down from the Sellion anthropometric landmark), Pronasale (TP) (The most anterior midsagittal point of the tip of the nose. It is not an anthropometrical landmark and was selected based on the facemask’s sealing point on the nose bridge), Menton (M) the lowest point in the middle on the lower border of the chin, Infraorbital (I) (Left and right. The lowest point on the anterior border of the bony eye socket), Tragion (T) (Left and right. The superior point on the juncture of the cartilaginous flap of the ear with the head), and Gonion (G) (Left and right. The most inferior midsagittal point of mandible)