title: The Comprehensive AOCMF Classification System: Midface Fractures - Level 2 Tutorial.
abstract: The AOCMF Classification Group developed a hierarchical three-level craniomaxillofacial classification system with increasing level of complexity and details. The highest level 1 system distinguish four major anatomical units including the mandible (code 91), midface (code 92), skull base (code 93), and cranial vault (code 94). This tutorial presents the level 2 system for the midface unit that concentrates on the location of the fractures within defined regions in the central (upper, intermediate, and lower) and lateral (zygoma, pterygoid) midface, as well as the internal orbit and palate. The level 2 midface fracture location outlines the topographic boundaries of the anatomical regions. The common nasoorbitoethmoidal and zygoma en bloc fracture patterns, as well as the time-honored Le Fort classification are taken into account. This tutorial is organized in a sequence of sections dealing with the description of the classification system with illustrations of the topographical cranial midface regions 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. Individual fracture mapping in these regions regarding severity, fragmentation, displacement of the fragment or bone defect is addressed in a more detailed level 3 system in the subsequent articles.
authors.affiliation: Clinic for Oral and Craniomaxillofacial Surgery, University Hospital Basel, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Kunz
authors.affiliation: AO Clinical Investigation and Documentation, AO Foundation, Audige's Dübendorf, Switzerland ; Research and Development Department, Schulthess Clinic, Zürich, Switzerland.
authors.forename: Laurent
authors.initials: L
authors.lastname: Audigé
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ludwig Maximilians Universität München, Germany.
authors.forename: Carl-Peter
authors.initials: CP
authors.lastname: Cornelius
authors.affiliation: Imaging Center Aarau, Institute of Radiology Zofingen Hospital, Zofingen, Switzerland.
authors.forename: Carlos H
authors.initials: CH
authors.lastname: Buitrago-Téllez
authors.affiliation: Division of Facial Plastic Surgery, Department of Otolaryngology-Head and Neck Surgery, Geisinger Medical Center, Danville, Pennsylvania.
authors.forename: John
authors.initials: J
authors.lastname: Frodel
authors.affiliation: Plastic, Reconstruction and Maxillofacial Surgery, Alpharetta, Georgia.
authors.forename: Randal
authors.initials: R
authors.lastname: Rudderman
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ludwig Maximilians Universität München, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Prein
keywords: anatomic regions; fracture classification; midface