The pterygo-maxillary or zygomatic fossa is an irregularly shaped cavity, situated below and on the inner side of the zygoma; bounded, in front, by the zygomatic surface of the superior maxillary bone and the ridge which descends from its malar process; behind, by the posterior border of the external pterygoid plate and the eminentia articularis; above, by the pterygoid ridge on the outer surface of the great wing of the sphenoid, and the under part of the squamous portion of the temporal; below by the alveolar border of the superior maxilla; internally, by the external pterygoid plate; and externally, by the zygomatic arch ramus of the lower jaw. It contains the lower part of the temporal, the external and internal pterygoid muscles, the internal maxillary artery and vein, and inferior maxillary nerve and their branches.

The infratemporal fossa is an irregularly shaped cavity that is a part of the skull. It is situated below and medial to the zygomatic arch.