The Imaging of Maxillofacial Trauma 2017

Facial fractures: The "bottom-up" approach

Given the demands of a busy high-volume trauma center, trauma radiologists are expected to evaluate an enormous number of images covering a multitude of facial bones in a short period of time in severely traumatized patients. Therefore, a comprehensive checklist, search pattern, and practical approach become indispensable for evaluation. Moreover, fracture complex classification conveys abundant information in a succinct shorthand fashion, which can be a large asset in a busy high-volume trauma center: reliably helping clinicians communicate urgent findings, make early treatment decisions, and effectively plan surgical approaches. Traditionally, radiologists' approach the CT axial dataset in top-down fashion: navigating their descent craniocaudal. However, a bottom-up approach may be advantageous, especially when it comes to facial fracture complex classification. Four key anatomic landmarks of the face, when evaluated sequentially in bottom-up fashion, are favorable to rapid single-sweep facial fracture characterization: the mandible, the pterygoid plates, the zygoma, and the bony orbits. That is, when done in succession: 1. Clearing the mandible rules out a panfacial smash fracture. 2. Clearing the pterygoid plates effectively rules out a Le Fort I, II, and III fracture. 3. Clearing the zygoma effectively rules out a zygomaticomaxillary complex (ZMC) type fracture. 4. Clearing the bony orbits effectively rules out a naso-orbital-ethmoid (NOE) fracture. Following this process of exclusion and elimination; as one ascends through the face, fracture characterization becomes more manageable and straightforward. Besides identifying all of the fractures and using the appropriate classification system, the radiologist also needs to recognize key clinically relevant soft tissue injuries that may be associated with facial fractures and thus should address these in the report.

ACR Appropriateness Criteria® Imaging of Facial Trauma Following Primary Survey

Maxillofacial trauma patients comprise a significant subset of patients presenting to emergency departments. Before evaluating for facial trauma, an emergency or trauma physician must perform a primary survey to ensure patient stabilization. Following this primary survey, this document discusses the following clinical scenarios for facial trauma: tenderness to palpation or contusion or edema over frontal bone (suspected frontal bone injury); pain with upper jaw manipulation or pain overlying zygoma or zygomatic deformity or facial elongation or malocclusion or infraorbital nerve paresthesia (suspected midface injury); visible nasal deformity or palpable nasal deformity or tenderness to palpation of the nose or epistaxis (suspected nasal bone injury); and trismus or malocclusion or gingival hemorrhage or mucosal hemorrhage or loose teeth or fractured teeth or displaced teeth (suspected mandibular injury). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Advanced Three-Dimensional Technologies in Craniofacial Reconstruction

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe the evolution of three-dimensional computer-aided reconstruction and its current applications in craniofacial surgery. 2. Recapitulate virtual surgical planning, or computer-assisted surgical simulation, workflow in craniofacial surgery. 3. Summarize the principles of computer-aided design techniques, such as mirror-imaging and postoperative verification of results. 4. Report the capabilities of computer-aided manufacturing, such as rapid prototyping of three-dimensional models and patient-specific custom implants. 5. Evaluate the advantages and disadvantages of using three-dimensional technology in craniofacial surgery. 6. Critique evidence on advanced three-dimensional technology in craniofacial surgery and identify opportunities for future investigation.

SUMMARY

Increasingly used in craniofacial surgery, virtual surgical planning is applied to analyze and simulate surgical interventions. Computer-aided design and manufacturing generates models, cutting guides, and custom implants for use in craniofacial surgery. Three-dimensional computer-aided reconstruction may improve results, increase safety, enhance efficiency, augment surgical education, and aid surgeons' ability to execute complex craniofacial operations. Subtopics include image analysis, surgical planning, virtual simulation, custom guides, model or implant generation, and verification of results. Clinical settings for the use of modern three-dimensional technologies include acquired and congenital conditions in both the acute and the elective settings. The aim of these techniques is to achieve superior functional and aesthetic outcomes compared to conventional surgery. Surgeons should understand this evolving technology, its indications, limitations, and future direction to use it optimally for patient care. This article summarizes advanced three-dimensional techniques in craniofacial surgery with cases highlighting clinical concepts.