1. Introduction

Facial trauma accounts for the majority of emergencydepartment visits in urban area. Motor vehicle accidents,assault, falls, and sports account for a majority of facialtrauma. Many of these patients have imaging studies forinjuries not apparent by direct inspection. The primaryrole of imaging studies in the facial trauma is to classifythe facial trauma by defining the number and location ofknown facial fractures, to identify additional fractures thatare missed by physical examination, and to evaluatecombined soft tissue injury. Moreover, radiologists mustpay special attention to identify combined life-threateningconditions such as injuries in the brain, spine and airway.

2. Imaging Techniques

Plain radiographs were considered standard imagingfor facial trauma. However, the superimposition of facialbony structures and air-containing structures such asparanasal sinuses and airways made interpretation offacial bone fracture inaccurate and difficult on plainradiographs. Moreover, plain radiographs do not providesufficient information to assess injury severity anddisplacement of the facial bone fracture, which areessential for emergent management and surgicalplanning. In addition, radiographic positioning is time-consuming, difficult and potentially dangerous for multi-trauma patients suspected cervical spine injury.Multidetector CT (MDCT) scanners have revolutionizedtrauma imaging and provide a fast, safe, cost-effective,and sensitive means for assessing trauma for bone andsoft tissue injuries. Furthermore, with the advent ofMDCT, facial scans can now be performedcontemporaneously with head, thoracic, and abdominalscans, facilitating a rapid assessment for trauma patientswith multiple potential injuries. Scanning is acquired atsubmillimeter thickness with overlap to generate high-quality multiplanar reformations and 3-D reconstructions.The routine scan range should be from the frontal sinusto hyoid bone for including basal skull, mandible andupper cervical spine. CT images are reviewed at 2 or 3-mm thick axial or coronal multiplanar reformations, andadditional sagittal reformations are also generated

according to the area of interest on a case by case basis.

3. Facial Bone Anatomy and Facial Buttress System

The facial skeleton is a complex structure formed by acombination of five paired bones and four unpairedbones. The anatomic relationship between these facialbones is complex. In spite of the complexity of the facialanatomy, pointing out the individual facial bone such aszygoma, palatine, maxillary and sphenoid bone isessential to interpret radiological images and tocommunicate with clinicians. In addition, the facialanatomy should be understood in terms of facial bones,adjacent soft tissue and organ, and functionally relevantstructures. The facial skeleton can be conceptualized asfour transverse and four paired vertical buttresses. Thevertically oriented struts directly or indirectly connect theanterior facial skeleton to the posterior skull base. Thegreater thickness of bone in the facial buttresses, bothhorizontal and vertical, with respect to the remainder ofthe facial skeleton provides a rigid protective frameworkfor the orbital contents, sinuses, teeth, and nasal cavity.Disruption of the facial buttresses can change facialdimensions and alter normal function, necessitatingsurgical fixation for restoration.

4. Classification of the Facial Bone Fracture

There are several classifications for facial fractures. Byanatomic location of bony injuries, facial fractures can beclassified into limited fractures, transfacial fractures, andsmash fractures. Limited fractures can involve only onebuttress strut (simple fractures) or two adjacentbuttresses struts (complex fractures). The examples ofthe simple fractures are nasal bone, maxillary alveolar,zygomatic arch, localized sinus wall and mandibularfracture. The complex fractures include nasofrontal,nasomaxillary, nasoethmoidal, zygomaticomaxillarycomplex, and malar(tripod) fracture. A transfacial fractureinvolves the pterygoid plates by definition, and thisincludes classic Le Fort fracture. A smash fracture is aseverely comminuted fracture that does not follow thepattern of a traditional transfacial fracture, this includesnaso-orbital-ethmoidal fracture. In another classification

Head and Neck Oct 10, Fri

09:00-09:30 Grand Ballroom 102RC 01 HN-03 Diagnostic imaging of the face and jaw

Chairperson(s) : Dong Woo Park Hanyang University Guri Hospital, KoreaDae Seob Choi Gyeongsang National University Hospital, Korea

Key concepts in facial trauma

Jin Woo Choi Konkuk University School of Medicine, Korea. cardijin@gmail.com

Head and Neck Oct 10, Fri

system that is used by surgeon, the osseous facialanatomy is divided into upper, middle, and lower thirds.The upper third of the face consists of the frontal boneabove the superior orbital rims and walls. The middlethird of the face extends from the superior orbital rimsinferiorly to the maxilla and thus includes the orbits; thenasal cavity; and the maxillary, ethmoid, and sphenoidsinuses. The lower third of the face consists of themandible. Classifying fractures by their location withregard to these facial thirds may be helpful for planningsurgical access. Another way of classifying facial bonefracture is anatomic grouping of the adjacent andfunctionally relevant facial bone as one compartment.

These compartments were grouped into nasal, orbital,zygomatic, maxillary and mandibular regions.

In this refresher course, I will provide an overview ofthe facial skeletal anatomy and describes the system offacial buttresses. Next, the spectrum of fractures thatmay be seen in facial skeletal trauma is described.Critical imaging features that may be seen and that arelikely to have a bearing on the clinical management,surgical repair, and outcome of facial trauma arediscussed. Last, surgically relevant complications that arepredictable on the basis of the fracture pattern seen atimaging are reviewed according to the facial buttressaffected by fracture.