Anatomy of the Orbit: Overall Skeletal and Topographical Configuration

Abstract

Objective: The intent of this chapter is to provide a systematic reappraisal of the bony anatomy of the orbit. The studies and the available literature on this topic are ever-expanding. The present knowledge shall be put into perspective.Material and Methods: Textbook and atlas descriptions served as a starting point for a comprehensive outline of the osseous anatomy of the orbits. To deepen the insight and understanding, a small selection of recent reports on specific structures has been reviewed. For visual purposes, photographs of PMHS (post mortem human subject) specimens and illustrations were used.Review/Results: The most distinctive feature of each orbit is the quadrangular pyramidal shape with a tetrahedron spire making up the orbital apex. The bony elements of the orbits are delineated with the sphenoid as backward foundation and starting base for the overall architectural composition. A closer look goes into the openings within the orbital precincts and reveals the subtleties and variations of the fissures, canals, grooves, foramina, notches, and fossae monitoring recent publications. The research modalities of these studies have shifted from dry skull investigations and PMHS dissections to modern imaging techniques (CT, MRI, CBCT) within defined living populations facilitating the analysis of hidden spaces or hard-to-reach structures in a non-destructive manner. Additional advantages of imaging include quantification and a detailed morphometric evaluation in the spirit of computational anatomy.Conclusion: In essence, the combination of traditional anatomic knowledge and the understanding of the tremendous complexity of variations characterized in new publications demands for a patient-specific diagnostic workup as exemplified in this book. As a matter of fact, however it is more likely to recognize and grasp features that one knows or knows about from previous intensive learning.