The AOCMF Classification Group developed a hierarchical three-level craniomaxillofacial classification system with increasing level of complexity and details. Within the midface (level 1 code 92), the level 2 system describes the location of the fractures within defined regions in the central and lateral midface including the internal orbit. This tutorial outlines the level 3 detailed classification system for fractures of the orbit. It depicts the orbital fractures according to the subregions defined as orbital rims, anterior orbital walls, midorbit, and apex. The system allows documentation of the involvement of specific orbital structures such as inferior orbital fissure, internal orbital buttress, the greater wing of sphenoid, lacrimal bone, superior orbital fissure, and optic canal. The classification system is presented along with rules for fracture location and coding, a series of case examples with clinical imaging and a general discussion on the design of this classification.
Keywords: anatomic regions; fracture classification; midface; orbit.