All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
Linguists and scholars of Fiqh define the beard as the hair which grows on the cheeks and the chin. The Maaliki scholars explicitly stated that it is prohibited to shave the hair which grows under the lower lip directly. An-Nafraawi a Maaliki scholar, said: “It is prohibited to remove the hair which grows under the lower lip, just as it is prohibited to remove the hair of the beard.”
As for the hair which grows on the cheekbones, none of the scholars considered it a part of the beard. Therefore, it is permissible to shave it.
Allaah Knows best.