title: The Comprehensive AOCMF Classification System: Midface Fractures - Level 3 Tutorial.
abstract: This tutorial outlines the details of the AOCMF image-based classification system for fractures of the midface at the precision level 3. The topography of the different midface regions (central midface-upper central midface, intermediate central midface, lower central midface-incorporating the naso-orbito-ethmoid region; lateral midface-zygoma and zygomatic arch, palate) is subdivided in much greater detail than in level 2 going beyond the Le Fort fracture types and its analogs. The level 3 midface classification system is presented along with guidelines to precisely delineate the fracture patterns in these specific subregions. It is easy to plot common fracture entities, such as nasal and naso-orbito-ethmoid, and their variants due to the refined structural layout of the subregions. As a key attribute, this focused approach permits to document the occurrence of fragmentation (i.e., single vs. multiple fracture lines), displacement, and bone loss. Moreover, the preinjury dental state and the degree of alveolar atrophy in edentulous maxillary regions can be recorded. On the basis of these individual features, tooth injuries, periodontal trauma, and fracture involvement of the alveolar process can be assessed. Coding rules are given to set up a distinctive formula for typical midface fractures and their combinations. The instructions and illustrations are elucidated by a series of radiographic imaging examples. A critical appraisal of the design of this level 3 midface classification is made.
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: AO Clinical Investigation and Documentation, AO Foundation, Dübendorf, Switzerland ; Research and Development Department, Schulthess Clinic, Zürich, Switzerland.
authors.forename: Laurent
authors.initials: L
authors.lastname: Audigé
authors.affiliation: Clinic for Oral and Craniomaxillofacial Surgery, University Hospital Basel, Basel, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Kunz
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: Plastic, Reconstruction & Maxillofacial Surgery, Alpharetta, Georgia.
authors.forename: Randal
authors.initials: R
authors.lastname: Rudderman
authors.affiliation: Clinic for Oral and Craniomaxillofacial Surgery, University Hospital Basel, Basel, Switzerland.
authors.forename: Joachim
authors.initials: J
authors.lastname: Prein
keywords: central and lateral midface; fracture classification; tooth injuries; zygoma