Multidetector CT of Mandibular Fractures, Reductions, and Complications: A Clinically Relevant Primer for the Radiologist

Abstract

After the nasal bones, the mandible is the second most common site of facial fractures, and mandibular fractures frequently require open reduction. In the trauma injury setting, multidetector computed tomography (CT) has become the cornerstone imaging modality for determining the most appropriate treatment management, fixation method, and surgical approach. Multidetector CT is also used to assess the adequacy of the reduction and evaluate potential complications in the postoperative period. For successful restoration of the mandible's form and function, as well as management of posttraumatic and postoperative complications, reconstructive surgeons are required to have a detailed understanding of mandibular biomechanics, occlusion, and anatomy. To provide added value in the diagnosis, treatment planning, and follow-up of mandibular fractures, radiologists should be aware of these concepts. Knowledge of the techniques commonly used to achieve occlusal and anatomic reduction and of the rationale behind the range of available treatment options for different injury patterns-from isolated and nondisplaced fractures to multisite and comminuted fractures-also is essential. This article focuses on the use of multidetector CT for pre- and postoperative evaluation of mandibular fractures and outlines fundamental concepts of diagnosis and management-beginning with an explanation of common fracture patterns and their biomechanical underpinnings, and followed by a review of the common postoperative appearances of these fractures after semirigid and rigid fixation procedures. Specific considerations regarding fractures in different regions of the tooth-bearing and non-tooth-bearing mandible and the unique issues pertaining to the edentulous atrophic mandible are reviewed, and key features that distinguish major from minor complications are described. (©)RSNA, 2016.

Facial fractures: classification and highlights for a useful report

“…Thanks to its widespread availability, computed tomography (CT) is the reference standard for facial imaging [18]. In patients with multiple trauma, facial CT can be easily incorporated into contrast-enhanced whole-body CT protocols, whereas in patients with low-impact trauma, CT images of the face can be acquired together with unenhanced CT studies of the brain or cervical spine [22,23].…”

“…Severely fragmented bone that has lost its periosteal attachment is likely to become devitalized and is typically removed. Mandibular fractures are often triangular basal fracture segments, sometimes called "basal triangles," that can be seen anywhere along the inferior border of the mandible [22,46].…”

“…When the mandibular canal is involved, the inferior alveolar nerve may be damaged, resulting in a loss of sensation, especially if displacement exceeds 5 mm [22,31,47].…”

Multidetector CT of Midfacial Fractures: Classification Systems, Principles of Reduction, and Common Complications

“…ZMC fractures produce facial asymmetry and enophthalmos, which are difficult to correct after development of malunion (52,74). Depressed zygomatic arch fractures can also cause restricted mouth opening from mandibular coronoid impingement (71,75). Complications related to plate fixation such as dehiscence, migration, osteomyelitis, and nonunion occur in less than 4% of midfacial fractures.…”

“…Mandible Fractures.-The principles guiding mandibular reconstruction are complex (75). With regard to midfacial fractures, the mandibular dental arch serves as a template for restoring pretrauma maxillary projection, incline, and occlusion (31) and must be either intact or Figure 36.…”