Craniomaxillofacial battle injuries: injury patterns, conventional treatment limitations and direction of future research

Traumatic maxillofacial injuries: Patterns, outcomes, and long-term follow-up of a military cohort

BACKGROUND/AIMS

Maxillofacial trauma poses a distinct challenge on the modern battlefield, and data on its long-term implications are scarce. The aim of this study was to investigate maxillofacial injury characteristics, outcomes, and complications along the continuum of care among hospitalized military personnel from the pre-hospital setting through long-term rehabilitation.

MATERIALS AND METHODS

A registry-based study was undertaken of three national trauma and rehabilitation registries: The Israel Defense Forces Trauma Registry (IDF-TR), which records pre-hospital data. The Israeli National Trauma Registry for in-hospital data and the Israel Ministry of Defense Rehabilitation Department (MOD-RD) registry contain long-term disability data. The cohort comprised IDF soldiers who suffered maxillofacial injuries between 1997 and 2020.

RESULTS

A total of 672 patients with maxillofacial injuries were included in the study, and 6.4% of all trauma admissions were related to maxillofacial injuries. Of these, 366 (54%) were injured in non-military (NMC) circumstances, and 306 (46%) were wounded in military circumstances (MC). The mechanisms of injury were mainly traffic-related among the NMC group compared with an explosion in the MC group. Maxillofacial fractures were frequently associated with traumatic brain injuries with higher rates in the NMC group than in the MC group (55% vs. 30%, p < .001). In a multivariate analysis, zygomatic and orbital fractures were associated with higher odds of concomitant head injury. The most common categories of long-term disability included central nervous system disorders, skull injuries, epilepsy, hearing impairment, ophthalmologic conditions, and post-traumatic stress disorder.

CONCLUSIONS

Maxillofacial injuries are often associated with concomitant traumatic brain injury. Long-term disabilities associated with these injuries included the central nervous system, hearing, ophthalmologic impairments, and post-traumatic stress disorder.

Quantifying Vascular Changes Surrounding Bone Regeneration in a Porcine Mandibular Defect Using Computed Tomography

Angiogenesis is a critical process essential for optimal bone healing. Several in vitro and in vivo systems have been previously used to elucidate some of the mechanisms involved in the process of angiogenesis, and at the same time, to test potential therapeutic agents and bioactive factors that play important roles in neovascularization. Computed tomography (CT) is a noninvasive imaging technique that has recently allowed investigators to obtain a diverse range of high-resolution, three-dimensional characterization of structures, such as bone formation within bony defects. Unfortunately, to date, angiogenesis evaluation relies primarily on histology, or ex vivo imaging and few studies have utilized CT to qualitatively and quantitatively study the vascular response during bone repair. In the current study a clinical CT-based technique was used to evaluate the effects of rhBMP-2 eluting graft treatment on soft tissue vascular architecture surrounding a large segmental bone defect model in the minipig mandible. The objective of this study was to demonstrate the efficacy of contrast-enhanced, clinical 64-slice CT technology in extracting quantitative metrics of vascular architecture over a 12-week period. The results of this study show that the presence of rhBMP-2 had a positive effect on vessel volume from 4 to 12 weeks, which was explained by a concurrent increase in vessel number, which was also significantly higher at 4 weeks for the rhBMP-2 treatment. More importantly, analysis of vessel architecture showed no changes throughout the duration of the study, indicating therapeutic safety. This study validates CT analysis as a relevant imaging method for quantitative and qualitative analysis of morphological characteristics of vascular tissue around a bone healing site. Also important, the study shows that CT technology can be used in large animal models and potentially be translated into clinical models for the development of improved methods to evaluate tissue healing and vascular adaptation processes over the course of therapy. This methodology has demonstrated sensitivity to tracking spatial and temporal changes in vascularization and has the potential to be applied to studying changes in other high-contrast tissues as well. Impact Statement Tissue engineering solutions depend on the surrounding tissue response to support regeneration. The inflammatory environment and surrounding vascular supply are critical to determining if therapies will survive, engraftment occurs, and native physiology is restored. This study for the first time evaluates the blood vessel network changes in surrounding soft tissue to a bone defect site in a large animal model, using clinically available computed tomography tools and model changes in vessel number, size, and architecture. While this study focuses on rhBMP2 delivery impacting surrounding vasculature, this validated method can be extended to studying the vascular network changes in other tissues as well.

Sequential sequestrations increase the incorporation and retention of multiple growth factors in mineralized collagen scaffolds

Trauma induced injuries of the mouth, jaw, face, and related structures present unique clinical challenges due to their large size and complex geometry. Growth factor signaling coordinates the behavior of multiple cell types following an injury, and effective coordination of growth factor availability within a biomaterial can be critical for accelerating bone healing. Mineralized collagen scaffolds are a class of degradable biomaterial whose biophysical and compositional parameters can be adjusted to facilitate cell invasion and tissue remodeling. Here we describe the use of modified simulated body fluid treatments to enable sequential sequestration of bone morphogenic protein 2 and vascular endothelial growth factor into mineralized collagen scaffolds for bone repair. We report the capability of these scaffolds to sequester 60–90% of growth factor from solution without additional crosslinking treatments and show high levels of retention for individual (>94%) and multiple growth factors (>88%) that can be layered into the material via sequential sequestration steps. Sequentially sequestering growth factors allows prolonged release of growth factors in vitro (>94%) and suggests the potential to improve healing of large-scale bone injury models in vivo. Future work will utilize this sequestration method to induce cellular activities critical to bone healing such as vessel formation and cell migration.

Trauma induced injuries of the mouth, jaw, face, and related structures present unique clinical challenges due to their large size and complex geometry.

Reconstructing the Face of War

Introduction

Ongoing combat operations in Iraq, Afghanistan, and other theaters have led to an increase in high energy craniomaxillofacial (CMF) wounds. These challenging injuries are typically associated with complex tissue deficiencies, evolving areas of necrosis, and bony comminution with bone and ballistic fragment sequestrum. Restoring form and function in these combat-sustained CMF injuries is challenging, and frequently requires local and distant tissue transfers. War injuries are different than the isolated trauma seen in the civilian sector. Donor sites are limited on patients with blast injuries and they may have preferences or functional reasons for the decisions to choose flaps from the available donor sites.

Methods

A case series of patients who sustained severe combat-related CMF injury and were treated at Walter Reed National Military Medical Center (WRNMMC) is presented. Our study was exempt from Institutional Review Board review, and appropriate written consent was obtained from all patients included in the study for the use of representative clinical images.

Results

Four patients treated by the CMF team at Walter Reed National Military Medical Center are presented. In this study, we highlight their surgical management by the CMF team at WRNMMC, detail their postoperative course, and illustrate the outcomes achieved using representative patient clinical images. We also supplement this case series demonstrating military approaches to complex CMF injuries with CMF reconstructive algorithms utilized by the senior author (EDR) in the management of civilian complex avulsive injuries of the upper, mid, and lower face are thoroughly reviewed.

Conclusion

While the epidemiology and characteristics of military CMF injuries have been well described, their management remains poorly defined and creates an opportunity for reconstructive principles proven in the civilian sector to be applied in the care of severely wounded service members. The War on Terror marks the first time that microsurgery has been used extensively to reconstruct combat sustained wounds of the CMF region. Our manuscript reviews various options to reconstruct these devastating CMF injuries and emphasizes the need for steady communication between the civilian and military surgical communities to establish the best care for these complex patients.

Three-dimensional printing for craniomaxillofacial regeneration

Craniomaxillofacial injuries produce complex wound environments involving various tissue types and treatment strategies. In a clinical setting, care is taken to properly irrigate and stabilize the injury, while grafts are molded in an attempt to maintain physiological functionality and cosmesis. This often requires multiple surgeries and grafts leading to added discomfort, pain and financial burden. Many of these injuries can lead to disfigurement and resultant loss of system function including mastication, respiration, and articulation, and these can lead to acute and long-term psychological impact on the patient. A main causality of these issues is the lack of an ability to spatially control pre-injury morphology while maintaining shape and function. With the advent of additive manufacturing (three-dimensional printing) and its use in conjunction with biomaterial regenerative strategies and stem cell research, there is an increased potential capacity to alleviate such limitations. This review focuses on the current capabilities of additive manufacturing platforms, completed research and potential for future uses in the treatment of craniomaxillofacial injuries, with an in-depth discussion of regeneration of the periodontal complex and teeth.