SN Classes Description 1 Class Ia and its variation SHH = SFH SHH > SFH SHH < SFH 2 Class IIb and its variation FH II = UFH = LFH UFH < LFH FH II > LFH FH II < LFH FH II > LFH 3 Class IIIc and its variation HC = FHI = SUFH I = LFH HC < FH I HC < SUFH I HC < LFH HC > FH I FH I > SUFH FH I < LFH SUFH < LFH 4 Class Vd and its variation IOD = NW IOD > NW IOD < NW 5 Class VIe and its variation IOD = OL IOD > OL IOL < OL 6 Class VIIf and its variation MW = 1.5 (NW) MW > 1.5 (NW) MW < 1.5 (NW) 7 Class VIIIg and its variation NW = 0.25 (UFW) NW > 0.25 (UFW) NW < 0.25 (UFW) The superscripts a, b, and c indicate two-, three-, and four-section facial profile canon, respectively.