Richard A. Hopper

Patterns and Outcomes of Pediatric Facial Fractures in the United States: A Survey of the National Trauma Data Bank

BACKGROUND Pediatric trauma involving the bones of the face is associated with severe injury and disability. Although much is known about the epidemiology of facial fractures in adults, little is known about national injury patterns and outcomes in children in the US. STUDY DESIGN The epidemiology of facial injuries in children and adolescents (ages 0 to 18 years) was described using the National Trauma Data Bank (2001 to 2005) to examine facial fracture pattern, mechanism, and concomitant injury by age. RESULTS A total of 12,739 (4.6%) facial fractures were identified among 277,008 pediatric trauma patient admissions. The proportion of patients with facial fractures increased substantially with age. The most common facial fractures were mandible (32.7%), nasal (30.2%), and maxillary/zygoma (28.6%). The most common mechanisms of injury were motor vehicle collision (55.1%), violence (11.8%), and falls (8.6%). These fracture patterns and mechanisms of injury varied with age. Compared with patients without facial fractures, patients with fractures exhibited substantial injury severity, hospital lengths of stay, ICU lengths of stay, ventilator days, and hospital charges. In addition, patients with facial fractures had more severe associated injury to the head and chest and considerably higher overall mortality. CONCLUSIONS Causes and patterns of facial fractures vary with age. Cranial and central facial injuries are more common among toddlers and infants, and mandible injuries are more common among adolescents. Although bony craniofacial trauma is relatively uncommon among the pediatric population, it remains a substantial source of mortality, morbidity, and hospital resource use. Continued efforts toward injury prevention are warranted.

Robin Sequence: From Diagnosis to Development of an Effective Management Plan

The triad of micrognathia, glossoptosis, and resultant airway obstruction is known as Robin sequence (RS). Although RS is a well-recognized clinical entity, there is wide variability in the diagnosis and care of children born with RS. Systematic evaluations of treatments and clinical outcomes for children with RS are lacking despite the advances in clinical care over the past 20 years. We explore the pathogenesis, developmental and genetic models, morphology, and syndromes and malformations associated with RS. Current classification systems for RS do not account for the heterogeneity among infants with RS, and they do not allow for prediction of the optimal management course for an individual child. Although upper airway obstruction for some infants with RS can be treated adequately with positioning, other children may require a tracheostomy. Care must be customized for each patient with RS, and health care providers must understand the anatomy and mechanism of airway obstruction to develop an individualized treatment plan to improve breathing and achieve optimal growth and development. In this article we provide a comprehensive overview of evaluation strategies and therapeutic options for children born with RS. We also propose a conceptual treatment protocol to guide the provider who is caring for a child with RS.

Feeder-free self-renewal of human embryonic stem cells in 3D porous natural polymer scaffolds.

Human embryonic stem cells (hESCs) are routinely cultured on fibroblast feeder layers or in fibroblast-conditioned medium, which requires continued supply of feeder cells and poses the risks of xenogenic contamination and other complications such as feeder-dependent outcome. Here, we demonstrate a strategy that supports sustained self-renewal of hESCs in a three-dimensional porous natural polymer scaffold, comprised of chitosan and alginate, without the support of feeder cells or conditioned medium. We assessed the pluripotency of the renewed hESCs both in vitro by evaluation of cellular proliferation, functionality, and gene activities for 21 days, and in vivo by implantation of the stem cell populated scaffolds in an immunodeficient mouse model to induce teratoma formation. The self-renewed stem cells can be easily recovered for subculture by decomposing the scaffold under a mild condition. We further subcultured recovered hESCs for 14 days and verified their pluripotency. In addition to providing a clean environment for stem cell renewal, this strategy, with the demonstrated biocompatibility and biodegradability of chitosan and alginate, may potentially allow for the direct implantation of stem cell populated scaffolds for a broad spectrum of applications in tissue engineering and regenerative medicine.

Isolated sagittal and coronal craniosynostosis associated with TWIST box mutations

Craniosynostosis, the premature fusion of one or more cranial sutures, affects 1 in 2,500 live births. Isolated single‐suture fusion is most prevalent, with sagittal synostosis occurring in 1/5,000 live births. The etiology of isolated (nonsyndromic) single‐suture craniosynostosis is largely unknown. In syndromic craniosynostosis, there is a highly nonrandom pattern of causative autosomal dominant mutations involving TWIST1 and fibroblast growth factor receptors (FGFRs). Prior to our study, there were no published TWIST1 mutations in the anti‐osteogenic C‐terminus, recently coined the TWIST Box, which binds and inhibits RUNX2 transactivation. RUNX2 is the principal master switch for osteogenesis. We performed mutational analysis on 164 infants with isolated, single‐suture craniosynostosis for mutations in TWIST1, the IgIIIa exon of FGFR1, the IgIIIa and IgIIIc exons of FGFR2, and the Pro250Arg site of FGFR3. We identified two patients with novel TWIST Box mutations: one with isolated sagittal synostosis and one with isolated coronal synostosis. Kress et al. [ 2006 ] reported a TWIST Box “nondisease‐causing polymorphism” in a patient with isolated sagittal synostosis. However, compelling evidence suggests that their and our sequence alterations are pathogenic: (1) a mouse with a mutation of the same residue as our sagittal synostosis patient developed sagittal synostosis, (2) mutation of the same residue precluded TWIST1 interaction with RUNX2, (3) each mutation involved nonconservative amino acid substitutions in highly conserved residues across species, and (4) control chromosomes lacked TWIST Box sequence alterations. We suggest that genetic testing of patients with isolated sagittal or coronal synostosis should include TWIST1 mutational analysis.

Evaluation and treatment of zygomatic fractures

Summary: Orbitozygomatic fractures are some of the most common facial fractures evaluated and treated by plastic surgeons. A considerable debate remains surrounding the manner of evaluation and appropriate treatment modalities. On the one hand, some would suggest that few fractures need formal open reduction and internal fixation, whereas others would argue that the pull of the strong masseter muscle ultimately leads to inferior and lateral rotation of the zygoma, which justifies open reduction and internal fixation of most fractures excepting those fractures that are nondisplaced at all points of articulation. The authors hope to shed some light on these issues by conveying their perspective on these fractures that has developed over several decades while servicing a single, major Level I trauma center. In general, the authors feel that through a detailed evaluation including an accurate physical examination of the face and orbit combined with detailed computed tomographic scanning of the craniofacial skeleton and soft tissues, an appropriate treatment plan can be generated. The common goal among all treatment plans should be the exact three-dimensional restoration of the disturbed anatomy, that is, anatomical reduction and the need for accurate restoration of orbital anatomy and volume when necessary.

Major morbidity and mortality rates in craniofacial surgery: an analysis of 8101 major procedures.

Background: The first combined evaluation of morbidity and mortality rates in craniofacial surgery was published 30 years ago; many surgeons believe these procedures have since become safer. The authors performed a contemporary evaluation of craniofacial morbidity and mortality rates to help surgeons more accurately counsel families about current risks, and to gain insight into reducing future incidences. Methods: This study used two methodologies to capture all serious morbidities and mortalities associated with major craniofacial procedures between 1990 and 2008: a comprehensive two-center retrospective review (Dallas and Seattle), and an Internet-based survey sent to all North American craniofacial centers. Results: Combining the two-center data with the survey results yielded a database of 7328 intracranial and 773 subcranial procedures, for a total of 8101 major craniofacial procedures. The combined intracranial major morbidity rate was less than 0.1 percent, and the combined mortality rate was 0.1 percent. Of the eight perioperative deaths following intracranial procedures, four (50 percent) intracranial mortalities were directly attributed to blood loss. The combined subcranial procedure major morbidity rate was 0.1 percent and the mortality rate was 0.3 percent (airway related). Comparing the earliest published intracranial mortality rate to our current review revealed a statistically significant reduction in incidence (p < 0.001). Conclusions: The incidence rates for serious morbidities and mortalities among major craniofacial procedures have significantly fallen since first published. On the basis of these analyses, the authors believe that a greater focus on protocols for airway management, blood salvage and replacement, age-appropriate deep venous thrombosis prophylaxis, and timing of subcranial midfacial advancements might result in further reductions in craniofacial mortality rates.

Evaluation of three-dimensional porous chitosan-alginate scaffolds in rat calvarial defects for bone regeneration applications.

This study investigated the use of three-dimensional porous chitosan-alginate (CA) scaffolds for critical size calvarial defect (diameter, 5.0 mm) repair in Sprague-Dawley rats. CA scaffolds have been used for in vitro culture of many cell types and demonstrated osteogenesis in ectopic locations in vivo, but have yet to be evaluated for functional bone tissue engineering applications. CA scaffolds demonstrated the ability to support undifferentiated mesenchymal stem cells (MSCs) in culture for 14 days in vitro and promoted spherical morphology. In vivo tests were performed using CA scaffolds and CA scaffolds with treatments including undifferentiated MSCs, bone marrow aspirate, and bone morphogenetic protein-2 (BMP-2) growth factor in comparison to unfilled bone defect used as a control. The samples were analyzed with MicroCT, histology, and immunohistochemical staining at 4 and 16 weeks. Partial defect closure was observed in all experimental groups at 16 weeks, with the greatest defect closure (71.56 ± 19.74%) in the animal group treated with CA scaffolds with BMP-2 (CA + BMP-2). The experimental samples demonstrated osteogenesis in histology and immunohistochemical staining, with the CA + BMP-2 group, showing the greatest level of osteogenesis. Tissue engineered CA scaffolds show promise in reconstruction of critical size bone defects.

Molding of the regenerate in mandibular distraction: clinical experience.

Initial clinical experience with distraction osteogenesis has demonstrated the risk of developing postdistraction malocclusion that requires secondary orthodontic correction. In addition, optimal mandibular form is not always achieved. Both animal studies and preliminary clinical investigations have suggested that the regenerate can be successfully “molded” during active mandibular distraction. The authors have applied this concept clinically to obtain a more desirable occlusal relationship in a group of mandibular distraction patients. Eleven patients are described in whom angulation of the distraction device or intermaxillary/interdental elastics were employed to mold the regenerate. Two representative case studies are provided to illustrate the principles. When using elastic traction to close an anterior open bite, care must be taken that extrusion of individual teeth is minimized by distributing the force over the entire dental arch, especially the basilar portions of the jaws. The authors demonstrate that molding of the regenerate can be successfully accomplished not only during device activation but also early in the consolidation period. The outer limit of the time window in which molding is effective remains to be defined.

Volumetric change of the medial pterygoid following distraction osteogenesis of the mandible: an example of the associated soft-tissue changes.

&NA; Mandibular distraction osteogenesis lengthens not only the affected skeleton but also the associated muscles of mastication. The purpose of this study was to determine medial pterygoid volume before and after distraction by using computed tomography. Using computed tomographic scans, the volume of the medial pterygoid muscle was determined before and after mandibular distraction in six pediatric patients. In four unilateral distraction patients (average age, 65 months), the average increase of the medial pterygoid muscle on the distracted side of the mandible was 29 percent, and on the contralateral nondistracted side, 10 percent. The average increase in medial pterygoid muscle volume in two bilateral distraction patients (each aged 8 months) was 75 percent. Results of this study demonstrate that distraction osteogenesis of the human mandible not only lengthens deficient bone, but it also increases the volume of the attached musculature. (Plast. Reconstr. Surg. 111: 1804, 2003.)

Craniofacial syndromes and surgery.

Learning Objectives: After studying this article, the participant should be able to: 1. Understand craniofacial dysmorphology and identify basic pediatric craniofacial syndromes. 2. Understand the functional concerns associated with these syndromes. 3. Achieve familiarity with the management protocols for the treatment of pediatric craniofacial syndromes. Summary: This article provides an overview of the diagnosis and management of infants and children with craniofacial syndromes. Treatment protocols from The Hospital for Sick Children, Toronto, Ontario, Canada, and Seattle Childrens Hospital, Seattle, Washington, are highlighted.