Variants of a mold are catalogued separately, so each one has its own sets and minifigs. Check these too if something you expect is missing here.

• 3626cpr1538 Minifig Head Galaxy Trooper, Stern Eyebrows, Mouth Lines / Dark Bluish Gray Visor with Silver Squares, Open Smile with Teeth Print Mold of this part
• 3626b Minifig Head [Plain] [Blocked Open Stud] this part is a print of it