The sphenozygomatic fissure

Abstract

The lateral (temporal) wall of the orbit separates it from the temporal fossa and the anterior part of the temporal muscle. Within this wall, the sphenozygomatic suture joins the greater wing of the sphenoid bone and the zygomatic bone. We retrospectively documented in cone-beam computed tomography the anatomy of the orbit in a 56-year-old female and we found a previously unreported anatomic variant. The greater wing of the sphenoid bone and the zygomatic bone were separated, bilaterally, by a large unossified space which we termed the sphenozygomatic fissure. This was merged inferiorly with the inferior orbital fissure. A possible imbalanced mechanism of membranous ossification of both the zygomatic bone and the orbital surface of the greater wing could be speculated as a possible cause for such sphenozygomatic fissure. This previously undocumented anatomic variant is of high clinical relevance, since it may allow orbital fat to herniate (or bulge) toward the temporal fossa, it may be easily damaged during minor trauma and it should be carefully approached during the surgery of the orbit through the lateral wall.

Keywords: cone-beam computed tomography; hiatus; orbit; orbital hernia; temporal fossa.