Table 1.

Segmentation steps for part 1.

Steps	Detected landmarks	Analysis on	Input volume	Output (updated) volume
1	Nasal tip	3-D soft tissue volume	Original patient data [Fig. 4(a)]	Skull base volume [Fig. 4(b)]
2	Nasal tip and frontal bone	3-D bone volume	Skull base volume [Fig. 4(b)]	Subvolume: orbital floor to orbital roof [Fig. 4(c)]
3	Zygoma bone	2-D axial bone	Subvolume: orbital floor to orbital roof [Fig. 4(c)]	Divided left and right subvolumes [Fig. 5(b)]
4	Orbital boundary bone	2-D axial bone	Divided left and right subvolumes [Fig. 5(b)]	Left and right orbital volumes [Fig. 6(c)]