stylomastoid artery stylomastoid artery the stylomastoid artery enters the stylomastoid foramen and supplies the tympanic cavity, the tympanic antrum and mastoid cells, and the semicircular canals. it is a branch of the posterior auricular artery, and thus part of the external carotid arterial system. stylomastoid arterythe arteries of the face and scalp.detailssourceposterior auricular arterysuppliestympanic cavity, tympanic antrum, mastoid cells, semicircular canalsidentifierslatinarteria stylomastoideata98a12.2.05.038ta24406fma49628anatomical terminology in the young subject a branch from this vessel forms, with the anterior tympanic artery from the internal maxillary, a vascular circle, which surrounds the tympanic membrane, and from which delicate vessels ramify on that membrane. it anastomoses with the superficial petrosal branch of the middle meningeal artery by a twig which enters the hiatus canalis facialis.