Right side
页 — the indexing head radical, originally a stylised drawing of a kneeling figure with an exaggerated head. Indexes
颠 in the head-and-face family alongside
顶 top of the head,
颊 cheek,
额 forehead. The original meaning of
颠 is the crown of the head, hence
颠倒 turning the head over, upside-down.