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

Frequency of concomitant injuries in maxillofacial trauma in a tertiary health care centre in India: A 5-year retrospective study

PURPOSE

Road traffic accidents (RTA), assaults, falls, and sports-related injuries are the leading causes of maxillofacial trauma. Due to quite different geographical environment and fast urbanization, the use of various protective equipment is restricted in India. Thus, compared to other countries, there might be a significant difference in the pattern and frequency of associated injuries among subjects with maxillofacial trauma. The present study was conducted to identify the causes and pattern of various maxillofacial fractures and the frequency of other related injuries among subjects with maxillofacial trauma.

METHODS

This is a cross-sectional retrospective study recording 2617 subjects with maxillofacial trauma. The patient demographics, causes of trauma, types of maxillofacial injury, and associated soft and hard tissue injuries were recorded. The types of maxillofacial and associated injuries were diagnosed from details of clinical examinations and the interpretation of various radiographs available in the file. The associated injuries were divided into head injury, other bony injuries, and soft tissue and vital structure injuries. Descriptive statistics and the test of proportion were used. A p value < 0.05 was considered as a level of significance.

RESULTS

The maxillofacial injuries were significantly common in patients aged 16 - 45 years (66.7%) than in patients aged ≤ 15 and > 46 years (33.3%) (p < 0.001). The RTA was the most common cause of maxillofacial injury (n = 2139, 81.7%), followed by fall (n = 206, 7.9%), other causes of injury (n = 178, 6.8%), and assaults (n = 94, 3.6%). The maxillofacial injury by 2-wheel vehicle accidents was significantly higher than that by 4-wheel vehicle and other vehicle accidents (p < 0.001). There was a significant correlation between alcohol and RTA (p < 0.001). The head injury (n = 931, 61.1%) was the most common associated injury, followed by soft tissue and vital structures injuries (n = 328, 21.5%) and other bone injuries (n = 264, 17.3%).

DISCUSSION

Head injury was the most common associated injury followed by soft tissue and vital structures and bone injuries among subjects with maxillofacial trauma. Clavicle fracture and injury to the lower extremities were the most common hard and soft tissue-associated injuries.

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.

CT characterisation and classification of feline temporomandibular joint trauma: a case series of 79 cats

OBJECTIVES

The aim of this study was to characterise and describe patterns of temporomandibular joint (TMJ) injuries occurring in cats using CT.

METHODS

A cross-sectional study was carried out in adherence with the STROBE guidelines. Among the medical and CT records of 79 cats, 158 TMJs were reviewed in a collaborative study between six institutions.

RESULTS

TMJ injuries were most commonly unilateral, representing 70.9% of cases. The mandibular condyle was fractured in 88 cases (55.7%) of the 158 TMJs observed. Of those, 84.0% were intra-articular condyle fractures, with the medial half of the mandibular condyle over-represented. Luxations occurred in 32.9% of cases, which was 19.0% of all evaluated TMJs. Rostrodorsal luxations were most common representing 87.0% of all luxations. Temporal bone fractures were observed in 30.4% of all cases, which was 18.4% of TMJs. The majority of fractures were of an unknown cause. When the cause was determined, road traffic accident (RTA) was the most frequent, followed by animal interaction, other external forces (sharp or blunt force) and high-rise trauma. Bilateral injuries were 13.1 times more likely to occur in high-rise trauma (P = 0.01) and temporal bone fracture was significantly associated with RTAs (P = 0.016). No other significant associations were observed between cause of injury and the resulting TMJ injury pattern.

CONCLUSIONS AND RELEVANCE

Various TMJ injury patterns can occur in cats as a result of trauma. Intra-articular fractures of the medial half of the mandibular condyle occur most commonly. Although unilateral injuries are more frequent, high-rise trauma tends to present with bilateral lesions. Further studies with a larger sample size should be performed to better understand TMJ patterns of injury and how they relate to possible causes.

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.

Imaging of the Temporomandibular Joint

Temporomandibular disorder (TMD) is a common musculoskeletal condition that causes pain and disability for patients and imposes a high financial burden on the healthcare system. The most common cause of TMD is internal derangement, mainly secondary to articular disc displacement. Multiple other pathologies such as inflammatory arthritis, infection, and neoplasm can mimic internal derangement. MRI is the modality of choice for evaluation of the TMJ. Radiologists need to be familiar with the normal anatomy and function of the TMJ and MR imaging of the internal derangement and other less common pathologies of the TMJ.

Re-evaluating the need for orthopantomography in the management of mandibular trauma: is computed tomography enough?

BACKGROUND

Mandibular fractures are frequent indications for computed tomography (CT) and orthopantomography (OPG) scans in emergency rooms. Numerous studies found CT to have higher sensitivity and enhanced accuracy compared to OPG in diagnosing mandible fractures. Controversy exists regarding additional need for OPG when evaluating dental trauma. This study investigates whether OPG adds diagnostic value to CT in mandibular trauma and whether additional OPG significantly alters management.

METHODS

A retrospective chart review identified 100 patients ≥ 18 years of age with known mandibular trauma who received CT and OPG in the emergency department between May 2015 and January 2020. All patients demonstrated a fracture in at least one study. CT and OPG studies were anonymized and randomized. A single attending surgeon evaluated mandible fracture and dental trauma characteristics and subsequently compared findings.

RESULTS

One hundred patient CT and OPG scans were reviewed. CT detected mandible fractures in all patients and OPG detected fractures in 93% (p = 0.01). Twenty-eight patients had different findings between scans. CT demonstrated 1 or more additional fracture(s) than OPG in 20 patients and dental trauma not seen on OPG in 4. OPG detected 1 fracture and no dental trauma that was not seen on CT. CT drove treatment-determining differences in 17 cases and OPG in 0 cases.

CONCLUSIONS

CT appears efficacious in detecting clinically significant mandible fractures and dental trauma with little additional benefit from OPG in emergency settings. Helical CT may be the only imaging necessary in evaluating patients with such trauma.

Radiological investigation of acute mandibular injury

This article focuses on the different imaging modalities used to evaluate acute mandibular fractures and explores important concepts relating to their diagnosis, investigation, and treatment. Significant focus will be given to exploring general management principles, considerations regarding first-line imaging, and recent technological advancement. Computed tomography (CT) is the preferred method when attempting to identify acute mandibular fractures, particularly in trauma patients, and has very high specificity and sensitivity. Multidetector CT now represents the standard of care, enabling fast scan times, reduced artifact, accurate reconstructed views, and three-dimensional (3D) reconstructions. Cone-beam CT is a newer advanced imaging modality that is increasingly being used worldwide, particularly in the ambulatory and intraoperative setting. It produces high-resolution images with submillimeter isotropic voxels, 3D and multiplanar reconstruction, and low radiation dose, however is less widely available and more expensive. Ultrasound is a valuable method in identifying a fracture in unstable patients, but is limited in its ability to detect nondisplaced fractures. Magnetic resonance imaging is useful in determining the presence of soft-tissue injury. CT angiography is invaluable in the assessment of potential vascular injury in condylar fracture dislocations.

Management of Traumatic Soft Tissue Injuries of the Face

Facial soft tissue injuries encompass a broad spectrum of presentations and often present significant challenges to the craniofacial surgeon. A thorough and systematic approach to these patients is critical to ensure that the patient is stabilized, other injuries identified, and the full extent of the injuries are assessed. Initial management focuses on wound cleaning with irrigation, hemostasis, and debridement of nonviable tissue. Definitive management is dependent on the region of the face involved with special considerations for critical structures such as the globe, lacrimal apparatus, facial nerve, and parotid duct. Following sound surgical principles, these injuries can be managed to maximize both functional and aesthetic outcomes while minimizing complications.

Postoperative Computed Tomography for Facial Fractures

In order for a radiologist to create reports that are meaningful to facial reconstructive surgeons, an understanding of the principles that guide surgical management and the hardware employed is imperative. This article is intended to promote efficient and salient reporting by illustrating surgical approaches and rationale. Hardware selection can be inferred and a defined set of potential complications anticipated when assessing the adequacy of surgical reconstruction on postoperative computed tomography for midface, internal orbital, and mandible fractures.

Radiology and A Radiologist: A Keystone in the Turmoil of Trauma Setting

Traumatic injuries are one of the leading causes of morbidity and mortality. Precise diagnosis and management in the golden hour are key to decrease morbidity and mortality. History and physical examination alone are insufficient to avoid misdiagnosis. In this article, we tried to determine the role of a radiologist and an appropriate imaging modality in a trauma setting. We conducted a literature review of published research articles. We used the keywords imaging, trauma, imaging and trauma, and trauma imaging essentials were used on PubMed and Google Scholar. The articles published in the English language from 2015 to 2020 with full free text available were included. Using the medical subject heading (MeSH) strategy, "diagnostic imaging" (Major {Majr}) and "multiple trauma/diagnostic imaging" (Mesh) on PubMed, we identified 34 papers after applying the inclusion and exclusion criteria. Twenty articles were finally selected which included studies from 2015 to 2020 with articles focusing on the adult population and acute cases. A radiologist and imaging modalities are the essential parts of a trauma setting to lower morbidity and mortality. X-rays and Extended Focussed Assessment with Sonography for Trauma (eFAST) are the first-line imaging modality in the acute trauma setting. However, the CT scan is the most sensitive modality that should be done to avoid misdiagnosis depending upon the patient's history and physical examination.

Facial and Dental Trauma

Dental and facial trauma are very common in a daily routine radiology practice. Knowledge of the functional anatomy of the mandibulofacial and maxillofacial regions forms the cornerstone of a thorough full radiologic evaluation of the patient with a dental and/or facial trauma. Cone beam computed tomography and multidetector computed tomography are currently considered the imaging modalities of choice. There are several patterns and classification systems for the various subtypes of mandibulofacial and maxillofacial fractures. They are discussed separately in this article with special attention to the types of dental trauma and orbital trauma.

Low-Dose Computed Tomographic Scans for Postoperative Evaluation of Craniomaxillofacial Fractures: A Pilot Clinical Study

Computed tomographic scans are frequently obtained following craniomaxillofacial fracture reconstruction. The additive radiation from such scans is not trivial; cumulative radiation exposure poses stochastic health risks. In this article, the authors postulate that a low-dose computed tomography protocol provides adequate image quality for postoperative evaluation of reconstructed craniomaxillofacial fractures. This study included patients for whom a computed tomographic scan was indicated following craniomaxillofacial fracture repair at a Level I trauma center. Postoperative craniomaxillofacial computed tomography was performed using a low-dose protocol, rather than standard protocols. A craniomaxillofacial surgeon and a radiologist interpreted the images to determine whether they were of sufficient quality. It was decided a priori that any inadequate low-dose computed tomography would require repeated scanning using standard protocols. The primary endpoint was the need for repeated computed tomography. In addition, the clarity of clinically significant anatomical landmarks on the images was graded on a five-point Likert scale. Twenty patients were scanned postoperatively using the low-dose protocol. Mean radiation dose (total dose-length product) from the low-dose protocol was 71 mGy · cm versus 532 mGy · cm for the preoperative computed tomographic scans that were obtained using conventional protocols (p < 0.001). All 20 low-dose computed tomographic scans were determined to provide satisfactory image quality. No patients required repeated computed tomography secondary to poor image quality. Low-dose computed tomography received high image-quality scores. A low-dose computed tomography protocol that delivers approximately 7.5-fold less radiation than the standard protocols was found to be adequate for postoperative evaluation of craniomaxillofacial fractures. Larger prospective studies may be warranted. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.

Facial fractures: classification and highlights for a useful report

In patients with facial trauma, multidetector computed tomography is the first-choice imaging test because it can detect and characterize even small fractures and their associated complications quickly and accurately. It has helped clinical management and surgical planning, so radiologists must communicate their findings to surgeons effectively. In Le Fort fractures, there is a breach between the pterygoid plates and the posterior maxilla. These fractures are classified in three basic patterns that can be combined and associated with various complications. Conceptualized when low-speed trauma was predominant, the Le Fort classification system has become less relevant giving more importance on maxillary occlusion-bearing segments. The classification of naso-orbito-ethmoid depends on the extent of injury to the attachment of the medial canthal tendon, with possible complications like nasofrontal duct disruption. Displaced fractures of the zygomaticomaxillary complex often widen the angle of the lateral orbital wall, resulting in increased orbital volume and sometimes in enophthalmos. Severe comminution or angulation can lead to wide surgical exposure. In orbital fractures, entrapment of the inferior rectus muscles can lead to diplopia, so it is important to assess its positioning and morphology. Orbital fractures can also result in injuries to the globe or infraorbital nerve. Frontal sinus fractures that extend through the posterior sinus wall can create a communication with the anterior cranial fossa resulting in leakage of cerebrospinal fluid, intracranial bleeding. It is essential to categorize fracture patterns and highlight features that may affect fracture management in radiology reports of facial trauma.

Multidetector computed tomography for facial trauma: structured reports and key observations for a systematic approach

Facial fractures, often related to traffic accidents, assault, work-related accidents, or falls, account for a considerable number of emergencies in our hospitals and are associated with high morbidity and mortality. Multidetector computed tomography (MDCT) is the imaging technique of choice in this scenario because it is widely available, fast, and useful for characterizing facial fractures and associated complications, including those located in the head. For all these reasons, MDCT is fundamental in the clinical management of these patients and in planning surgery. This paper describes the radiological anatomy of the facial region, underlining the importance of the facial buttresses, and it indicates the key points necessary for carrying out a structured approach and elaborating the corresponding radiologic report.

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

The advent of titanium hardware, which provides firm three-dimensional positional control, and the exquisite bone detail afforded by multidetector computed tomography (CT) have spurred the evolution of subunit-specific midfacial fracture management principles. The structural, diagnostic, and therapeutic complexity of the individual midfacial subunits, including the nose, the naso-orbito-ethmoidal region, the internal orbits, the zygomaticomaxillary complex, and the maxillary occlusion-bearing segment, are not adequately reflected in the Le Fort classification system, which provides only a general framework and has become less relevant in contemporary practice. The purpose of this article is to facilitate the involvement of radiologists in the delivery of individualized multidisciplinary care to adults who have sustained blunt trauma and have midfacial fractures by providing a clinically relevant review of the role of multidetector CT in the management of each midfacial subunit. Surgically relevant anatomic structures, search patterns, critical CT findings and their management implications, contemporary classification systems, and common posttraumatic and postoperative complications are emphasized. ^©RSNA, 2018.

New and emerging patient-centered CT imaging and image-guided treatment paradigms for maxillofacial trauma

This article reviews the conceptual framework, available evidence, and practical considerations pertaining to nascent and emerging advances in patient-centered CT-imaging and CT-guided surgery for maxillofacial trauma. These include cinematic rendering-a novel method for advanced 3D visualization, incorporation of quantitative CT imaging into the assessment of orbital fractures, low-dose CT imaging protocols made possible with contemporary scanners and reconstruction techniques, the rapidly growing use of cone-beam CT, virtual fracture reduction with design software for surgical pre-planning, the use of 3D printing for fabricating models and implants, and new avenues in CT-guided computer-aided surgery.

Simultaneous head and facial computed tomography scans for assessing facial fractures in patients with traumatic brain injury

INTRODUCTION

Patients with traumatic brain injury (TBI) may have concomitant facial fractures. While most head injury patients receive head computed tomography (CT) scans for initial evaluation, the objective of our study was to investigate the value of simultaneous facial CT scans in assessing facial fractures in patients with TBI.

METHODS

From January 1, 2015 to December 31, 2015, 1649 consecutive patients presenting to our emergency department (ED) with a TBI who received CT scans using the protocol for head and facial bones were enrolled. The clinical data and CT images were reviewed via a standardized format.

RESULTS

In our cohort, 200 patients (12.1%) had at least one facial fracture shown on the CT scans. Patients with facial fractures were more likely to have initial loss of consciousness (ILOC; p<0.001), a Glasgow coma scale of 8 or less (p<0.001), moderate or severe degrees of head injury severity scale (p<0.001), positive physical examination findings (p<0.001), and positive CT cranial abnormalities (p<0.001). A total of 166 (83.0%) patients with facial fractures required further facial CT scans instead of conventional head CT scans alone. Surgical intervention was mandatory in 73 (44.0%) of the 166 patients, who more frequently exhibited fractures of the lower third of the face (p<0.001) and orbital fractures (p=0.019).

CONCLUSIONS

TBI patients with risk factors may have a higher probability of concomitant facial fractures. Fractures of the lower third of the face and orbit are easily overlooked in routine head CT scans but often require surgical intervention. Therefore, simultaneous head and facial CT scans are suggested in selected TBI patients.