Extensive titanium mesh invasive cranial fibrous dysplasia

Background:

Craniofacial fibrous dysplasia (FD) is a benign lesion. It presents as bony swelling. Even after complete excision, it has a tendency to recur due to some residual lesion in normal bone. Recurrence at same site is common, but it recurs in bone. We are reporting a rare case of recurrent FD engulfing titanium mesh.

Case Description:

A 22-year-old girl, who underwent frontal FD excision and reconstruction using titanium mesh surgery 2 years back, came with complaint of progressive bony swelling at same site for 1 year. CT head confirmed bony lesion involving mesh, frontal air sinus. She underwent complete excision of lesion and cranioplasty using bony cement. Biopsy confirmed recurrence of FD and invasion of titanium mesh.

Conclusion:

Recurrence of FD, involving cranioplasty titanium mesh, is extremely rare. It suggests local invasiveness of lesion. Recurrence can be prevented by excision of lesion with free bony margins.

FACE-Q Craniofacial Module: Part 1 validation of CLEFT-Q scales for use in children and young adults with facial conditions

BACKGROUND

The CLEFT-Q includes 12 independently functioning scales that measure appearance (face, nose, nostrils, teeth, lips, jaws), health-related quality of life (psychological, social, school, speech distress), and speech function, and an eating/drinking checklist. Previous qualitative research revealed that the CLEFT-Q has content validity in noncleft craniofacial conditions. This study aimed to examine the psychometric performance of the CLEFT-Q in an international sample of patients with a broad range of facial conditions.

METHODS

Data were collected between October 2016 and December 2019 from 2132 patients aged 8 to 29 years with noncleft facial conditions. Rasch measurement theory (RMT) analysis was used to examine Differential Item Function (DIF) by comparing the original CLEFT-Q sample and the new FACE-Q craniofacial sample. Reliability and validity of the scales in a combined cleft and craniofacial sample (n=4743) were examined.

RESULTS

DIF was found for 23 CLEFT-Q items when the datasets for the two samples were compared. When items with DIF were split by sample, correlations between the original and split person locations showed that DIF had negligible impact on scale scoring (correlations ≥0.995). In the combined sample, RMT analysis led to the retention of original content for ten CLEFT-Q scales, modification of the Teeth scale, and the addition of an Eating/Drinking scale. Data obtained fit with the Rasch model for 11 scales (exception School, p=0.04). Person Separation Index and Cronbach alpha values met the criteria.

CONCLUSION

The scales described in this study can be used to measure outcomes in children and young adults with cleft and noncleft craniofacial conditions.

Responses of neurons in rostral ventromedial medulla to nociceptive stimulation of craniofacial region and tail in rats

The rostral ventromedial medulla (RVM) plays a key role in the endogenous modulation of nociceptive transmission in the central nervous system (CNS). The primary aim of this study was to examine whether the activities of RVM neurons were related to craniofacial nociceptive behaviour (jaw-motor response, JMR) as well as the tail-flick response (TF). The activities of RVM neurons and TF and JMR evoked by noxious heating of the tail or perioral skin were recorded simultaneously in lightly anaesthetized rats. Tail or perioral heating evoked the TF and JMR, and the latency of the JMR was significantly shorter (P < 0.001) than that of the TF. Of 89 neurons recorded in RVM, 40 were classified as ON-cells, 27 as OFF-cells, and 22 as NEUTRAL-cells based on their responsiveness to heating of the tail. Heating at either site caused an increase in ON-cell and decrease in OFF-cell activity before the occurrence of the TF and JMR, but did not alter the activity of NEUTRAL cells. Likewise, noxious stimulation of the temporomandibular joint had similar effects on RVM neurons. These findings reveal that the JMR is a measure of the excitability of trigeminal and spinal nociceptive circuits in the CNS, and that the JMR as well as TF can be used for studying processes related to descending modulation of pain. The findings also support the view that RVM ON- and OFF-cells play an important role in the elaboration of diverse nociceptive behaviours evoked by noxious stimulation of widely separated regions of the body.

Differential developmental toxicity of crude oil in early life stages of Atlantic halibut (Hippoglossus hippoglossus)

To further understand the complexity of developmental toxicity of dispersed oil and importance of exposure timing on fish early life stages, Atlantic halibut (Hippoglossus hippoglossus) were exposed to environmentally relevant concentrations through two embryonic developmental windows: the first period occurred during the epiboly process (named as "early embryonic exposure") and the second period overlapped the ontogenesis and cardiogenesis processes (named as "late embryonic exposure"). Following 72 hour oil exposure, embryos were transferred to clean seawater and a toxicity screening was performed in the yolk-sac larvae until first-feeding stages (56 days). The current study demonstrated that the exposure timing is essential for the development of toxic effects of crude oil in Atlantic halibut. Neither embryonic exposures (early or late) showed notable acute toxicity during exposure, yet both showed global latent teratogenic effects during yolk sac stages. Fish exposed during organogenesis (late) displayed stronger and more severe toxic effects than fish exposed during epiboly process (early), including reduced condition, severe craniofacial deformities and cardiovascular disruptions. The uptake level of polycyclic aromatic hydrocarbons into larval tissue and metabolic activity were greater following the late embryonic exposure and remained high during the depuration period at the highest exposure concentration. Overall, the long yolk sac stage development timing of Atlantic halibut makes this species a good candidate for evaluation of embryonic crude oil toxicity and its mechanisms.

Symmetry and fluctuation of cell movements in neural crest-derived facial mesenchyme

In the face, symmetry is established when bilateral streams of neural crest cells leave the neural tube at the same time, follow identical migration routes and then give rise to the facial prominences. However, developmental instability exists, particularly surrounding the steps of lip fusion. The causes of instability are unknown but inability to cope with developmental fluctuations are a likely cause of congenital malformations, such as non-syndromic orofacial clefts. Here, we tracked cell movements over time in the frontonasal mass, which forms the facial midline and participates in lip fusion, using live-cell imaging of chick embryos. Our mathematical examination of cell velocity vectors uncovered temporal fluctuations in several parameters, including order/disorder, symmetry/asymmetry and divergence/convergence. We found that treatment with a Rho GTPase inhibitor completely disrupted the temporal fluctuations in all measures and blocked morphogenesis. Thus, we discovered that genetic control of symmetry extends to mesenchymal cell movements and that these movements are of the type that could be perturbed in asymmetrical malformations, such as non-syndromic cleft lip.

This article has an associated ‘The people behind the papers’ interview.

Highlighted Article: Live imaging of the chick embryo face followed by mathematical analysis of mesenchymal cell tracks captures novel fluctuations between states of order/disorder as well as symmetry/asymmetry, revealing developmental instabilities that are part of normal morphogenesis.

Growing skull fractures of the orbital roof: a multicentric experience with 28 patients

BACKGROUND

Growing skull fracture (GSF) is a rare condition that may complicate pediatric head trauma. Patients may present with delayed-onset neurological manifestations.

AIM

This study aims to highlight the different presentations, methods of evaluation, treatment modalities, and outcomes in patients with orbital roof GSF.

METHODS

This retrospective multicentric cohort study reviewed the hospital records of children with GSF who presented at the Craniomaxillofacial Plastic Surgery Department, and Neurosurgery Department with Otorhinolaryngology Department (Maxillofacial unit), from 2011 to 2020. The collected data included age, gender, delay, manifestations, findings of imaging techniques, surgical treatment, complications, and satisfaction of patients' parents.

RESULTS

Twenty-eight patients with orbital roof GSF were included in this study. Most of the patients (82.1%) were boys, and the mean (SD) age was 5 (2) years old. Head trauma was caused by falls in all cases. Clinical manifestations included eyelid swelling (75%), pulsatile proptosis (25%), headache (17.9%), and seizures (10.7%). The mean (SD) diameter of bony defects was 24.3 (8.7) mm. Duraplasty alone was performed in 57.1%, while dura-cranioplasty was done in 42.9% of patients. Dural reconstruction was done using pericranial graft in 82.1% and artificial grafts in 17.9% of patients. Most of the parents (95%) were absolutely satisfied. No mortalities or recurrence of symptoms were recorded. The median follow-up period after surgery was 3.9 years.

CONCLUSION

Orbital roof GSF should be considered among the differential diagnoses in pediatric patients with history of head trauma presenting with ocular and/or neurological manifestations. Duraplasty is mandatory in all cases, whereas cranioplasty is required mainly in cases with large bony defects more than 25 mm. Prognosis in most patients was good both subjectively and objectively.

Evaluation of the OSA treatment protocol in syndromic craniosynostosis during the first 6 years of life

INTRODUCTION

Obstructive sleep apnea (OSA) is frequently present in patients with syndromic craniosynostosis. The aim of this study is to determine the long-term effectiveness of our OSA treatment protocol in our tertiary center in a cohort of children with syndromic craniosynostosis.

METHODS

Children with syndromic craniosynostosis born between January 2005 and December 2013 were eligible for inclusion (n = 114). Data from ambulatory and inhospital polysomnographies were used. The obstructive-apnea/hypopnea index was used for OSA classification.

RESULTS

Polysomnographies were performed in 83 patients. Mild OSA was diagnosed in 19, moderate in six, and severe in seven children. Of the 32 patients with OSA, 12 patients (37.5%) initially received expectant care of which OSA resolved spontaneously in nine without recurrence. Twenty patients were surgically treated. Adenotonsillectomy (ATE) had a 90% success rate with no OSA recurrence. Monobloc surgery was performed in four patients with mild OSA, although not OSA-indicated. Monobloc was performed for moderate or severe OSA in six patients, in four patients in combination with ATE and with mandibular distraction in one. Monobloc surgery for moderate or severe OSA had a 100% success rate in treating OSA and decannulation.

CONCLUSION

Expectant care is often sufficient to resolve mild OSA in patients with syndromic craniosynostosis, and should also be considered in patients with moderate OSA with close follow-up. ATE has an important role in the OSA treatment protocol. Monobloc surgery, combined with mandibular distraction on indication, is effective in resolving moderate to severe OSA with a stable long-term result.

FACE-Q craniofacial module: Part 2 Psychometric properties of newly developed scales for children and young adults with facial conditions

BACKGROUND

The FACE-Q Craniofacial Module is a patient-reported outcome measure designed for patients aged 8 to 29 years with conditions associated with a facial difference. In part 1, we describe the psychometric findings for the original CLEFT-Q scales tested in patients with cleft and noncleft facial conditions. The aim of this study was to examine psychometric performance of new FACE-Q Craniofacial Module scales.

METHODS

Data were collected between December 2016 and December 2019 from patients aged 8 to 29 years with conditions associated with a visible or functional facial difference. Rasch measurement theory (RMT) analysis was used to examine psychometric properties of each scale. Scores were transformed from 0 (worst) to 100 (best) for tests of construct validity.

RESULTS

1495 participants were recruited with a broad range of conditions (e.g., birthmarks, facial paralysis, craniosynostosis, craniofacial microsomia, etc.) RMT analysis resulted in the refinement of 7 appearance scales (Birthmark, Cheeks, Chin, Eyes, Forehead, Head Shape, Smile), two function scales (Breathing, Facial), and an Appearance Distress scale. Person separation index and Cronbach alpha values met criteria. Three checklists were also formed (Eye Function, and Eye and Face Adverse Effects). Significantly lower scores on eight of nine scales were reported by participants whose appearance or functional difference was rated as a major rather than minor or no difference. Higher appearance distress correlated with lower appearance scale scores.

CONCLUSION

The FACE-Q Craniofacial Module scales can be used to collect and compare patient reported outcomes data in children and young adults with a facial condition.

A landmark-free morphometrics pipeline for high-resolution phenotyping: application to a mouse model of Down syndrome

Characterising phenotypes often requires quantification of anatomical shape. Quantitative shape comparison (morphometrics) traditionally uses manually located landmarks and is limited by landmark number and operator accuracy. Here, we apply a landmark-free method to characterise the craniofacial skeletal phenotype of the Dp1Tyb mouse model of Down syndrome and a population of the Diversity Outbred (DO) mouse model, comparing it with a landmark-based approach. We identified cranial dysmorphologies in Dp1Tyb mice, especially smaller size and brachycephaly (front-back shortening), homologous to the human phenotype. Shape variation in the DO mice was partly attributable to allometry (size-dependent shape variation) and sexual dimorphism. The landmark-free method performed as well as, or better than, the landmark-based method but was less labour-intensive, required less user training and, uniquely, enabled fine mapping of local differences as planar expansion or shrinkage. Its higher resolution pinpointed reductions in interior mid-snout structures and occipital bones in both the models that were not otherwise apparent. We propose that this landmark-free pipeline could make morphometrics widely accessible beyond its traditional niches in zoology and palaeontology, especially in characterising developmental mutant phenotypes.

Heading for higher ground: Developmental origins and evolutionary diversification of the amniote face

Amniotes, a clade of terrestrial vertebrates, which includes all of the descendants of the last common ancestor of the reptiles (including dinosaurs and birds) and mammals, is one of the most successful group of animals on our planet. In addition to having an egg equipped with an amnion, an adaptation to lay eggs on land, amniotes possess a number of other major morphological characteristics. Chief among them is the amniote skull, which can be classified into several major types distinguished by the presence and number of temporal fenestrae (windows) in the posterior part. Amniotes evolved from ancestors who possessed a skull composed of a complex mosaic of small bones separated by sutures. Changes in skull composition underlie much of the large-scale evolution of amniotes with many lineages showing a trend in reduction of cranial elements known as the "Williston's Law." The skull of amniotes is also arranged into a set of modules of closely co-evolving bones as revealed by modularity and integration tests. One of the most consistently recovered and at the same time most versatile modules is the "face," anatomically defined as the anterior portion of the head. The faces of amniotes display extraordinary amount of variation, with many adaptive radiations showing parallel tendencies in facial scaling, e.g., changes in length or width. This review explores the natural history of the amniote face and discusses how a better understanding of its anatomy and developmental biology helps to explain the outstanding scale of adaptive facial diversity. We propose a model for facial evolution in the amniotes, based on the differential rate of cranial neural crest cell proliferation and the timing of their skeletal differentiation.

Best practice guidelines in managing the craniofacial aspects of skeletal dysplasia

Background

Recognition and appropriate management of the craniofacial manifestations of patients with skeletal dysplasia are challenging, due to the rarity of these conditions, and dearth of literature to support evidence-based clinical decision making.

Methods

Using the Delphi method, an international, multi-disciplinary group of individuals, with significant experience in the care of patients with skeletal dysplasia, convened to develop multi-disciplinary, best practice guidelines in the management of craniofacial aspects of these patients.

Results

After a comprehensive literature review, 23 initial statements were generated and critically discussed, with subsequent development of a list of 22 best practice guidelines after a second round voting.

Conclusions

The guidelines are presented and discussed to provide context and assistance for clinicians in their decision making in this important and challenging component of care for patients with skeletal dysplasia, in order standardize care and improve outcomes.

Recent update on craniofacial tissue engineering

The craniofacial region consists of several different tissue types. These tissues are quite commonly affected by traumatic/pathologic tissue loss which has so far been traditionally treated by grafting procedures. With the complications and drawbacks of grafting procedures, the emerging field of regenerative medicine has proved potential. Tissue engineering advancements and the application in the craniofacial region is quickly gaining momentum although most research is still at early in vitro/in vivo stages. We aim to provide an overview on where research stands now in tissue engineering of craniofacial tissue; namely bone, cartilage muscle, skin, periodontal ligament, and mucosa. Abstracts and full-text English articles discussing techniques used for tissue engineering/regeneration of these tissue types were summarized in this article. The future perspectives and how current technological advancements and different material applications are enhancing tissue engineering procedures are also highlighted. Clinically, patients with craniofacial defects need hybrid reconstruction techniques to overcome the complexity of these defects. Cost-effectiveness and cost-efficiency are also required in such defects. The results of the studies covered in this review confirm the potential of craniofacial tissue engineering strategies as an alternative to avoid the problems of currently employed techniques. Furthermore, 3D printing advances may allow for fabrication of patient-specific tissue engineered constructs which should improve post-operative esthetic results of reconstruction. There are on the other hand still many challenges that clearly require further research in order to catch up with engineering of other parts of the human body.

An Irf6-Esrp1/2 regulatory axis controls midface morphogenesis in vertebrates

Irf6 and Esrp1 are important for palate development across vertebrates. In zebrafish, we found that irf6 regulates the expression of esrp1 We detailed overlapping Irf6 and Esrp1/2 expression in mouse orofacial epithelium. In zebrafish, irf6 and esrp1/2 share expression in periderm, frontonasal ectoderm and oral epithelium. Genetic disruption of irf6 and esrp1/2 in zebrafish resulted in cleft of the anterior neurocranium. The esrp1/2 mutant also developed cleft of the mouth opening. Lineage tracing of cranial neural crest cells revealed that the cleft resulted not from migration defect, but from impaired chondrogenesis. Analysis of aberrant cells within the cleft revealed expression of sox10, col1a1 and irf6, and these cells were adjacent to krt4+ and krt5+ cells. Breeding of mouse Irf6; Esrp1; Esrp2 compound mutants suggested genetic interaction, as the triple homozygote and the Irf6; Esrp1 double homozygote were not observed. Further, Irf6 heterozygosity reduced Esrp1/2 cleft severity. These studies highlight the complementary analysis of Irf6 and Esrp1/2 in mouse and zebrafish, and identify a unique aberrant cell population in zebrafish expressing sox10, col1a1 and irf6 Future work characterizing this cell population will yield additional insight into cleft pathogenesis.

99mTc-UBI 29-41 bone SPECT/CT scan in craniofacial Actinomyces israelii: Misdiagnosis of cranial bone tumor - A case report

Background:

Actinomycosis is a rare infection, frequently misdiagnosed as a neoplasia. This chronic and granulomatous disease is caused by Actinomyces israelii species. Cervicofacial actinomycosis occurs in 60% of cases and the diagnosis is commonly made by histopathology study.

Case Description:

We report a case of fronto-orbital osteomyelitis initially misdiagnosed as a cranial bone meningioma, but later proved to be a case of actinomycosis. ^99mTechnetium (^99mTc) three-phase bone single-photon emission computed tomography/computed tomography (SPECT/CT) and ^99mTc-ubiquicidin (UBI) 29-41 bone SPECT/CT scans were performed to corroborate the control of the infection.

Conclusion:

Craniofacial actinomycosis is the most common presentation of actinomycosis. However, it continues to be a rare and difficult disease to diagnose and is often confused with a neoplastic process. The ^99mTc-UBI 29-41 bone SPECT/CT scan could be an auxiliary noninvasive diagnostic alternative and a follow-up method for these patients.

Evo-devo studies of cyclostomes and the origin and evolution of jawed vertebrates

Modern vertebrates consist of two sister groups: cyclostomes and gnathostomes. Cyclostomes are a monophyletic jawless group that can be further divided into hagfishes and lampreys, which show conspicuously different developmental and morphological patterns. However, during early pharyngula development, there appears to be a stage when the embryos of hagfishes and lampreys resemble each other by showing an "ancestral" craniofacial pattern; this pattern enables morphological comparison of hagfish and lamprey craniofacial development at late stages. This cyclostome developmental pattern, or more accurately, this developmental pattern of the jawless grade of vertebrates in early pharyngula was very likely shared by the gnathostome stem before the division of the nasohypophyseal placode led to the jaw and paired nostrils. The craniofacial pattern of the modern jawed vertebrates seems to have begun in fossil ostracoderms (including galeaspids), and was completed by the early placoderm lineages. The transition from jawless to jawed vertebrates was thus driven by heterotopy of development, mainly caused by separation and shift of ectodermal placodes and resultant ectomesenchymal distribution, and shifts of the epithelial-mesenchymal interactions that underlie craniofacial differentiation. Thus, the evolution of the jaw was not a simple modification of the mandibular arch, but a heterotopic shift of the developmental interactions involving not only the mandibular arch, but also the premandibular region rostral to the mandibular arch.

OFCD syndrome and extraembryonic defects are revealed by conditional mutation of the Polycomb-group repressive complex 1.1 (PRC1.1) gene BCOR

BCOR is a critical regulator of human development. Heterozygous mutations of BCOR in females cause the X-linked developmental disorder Oculofaciocardiodental syndrome (OFCD), and hemizygous mutations of BCOR in males cause gestational lethality. BCOR associates with Polycomb group proteins to form one subfamily of the diverse Polycomb repressive complex 1 (PRC1) complexes, designated PRC1.1. Currently there is limited understanding of differing developmental roles of the various PRC1 complexes. We therefore generated a conditional exon 9-10 knockout Bcor allele and a transgenic conditional Bcor expression allele and used these to define multiple roles of Bcor, and by implication PRC1.1, in mouse development. Females heterozygous for Bcor exhibiting mosaic expression due to the X-linkage of the gene showed reduced postnatal viability and had OFCD-like defects. By contrast, Bcor hemizygosity in the entire male embryo resulted in embryonic lethality by E9.5. We further dissected the roles of Bcor, focusing on some of the tissues affected in OFCD through use of cell type specific Cre alleles. Mutation of Bcor in neural crest cells caused cleft palate, shortening of the mandible and tympanic bone, ectopic salivary glands and abnormal tongue musculature. We found that defects in the mandibular region, rather than in the palate itself, led to palatal clefting. Mutation of Bcor in hindlimb progenitor cells of the lateral mesoderm resulted in 2/3 syndactyly. Mutation of Bcor in Isl1-expressing lineages that contribute to the heart caused defects including persistent truncus arteriosus, ventricular septal defect and fetal lethality. Mutation of Bcor in extraembryonic lineages resulted in placental defects and midgestation lethality. Ubiquitous over expression of transgenic Bcor isoform A during development resulted in embryonic defects and midgestation lethality. The defects we have found in Bcor mutants provide insights into the etiology of the OFCD syndrome and how BCOR-containing PRC1 complexes function in development.

Acellular dense collagen-S53P4 bioactive glass hybrid gel scaffolds form more bone than stem cell delivered constructs

Dense collagen (DC) gels facilitate the osteoblastic differentiation of seeded dental pulp stem cells (DPSCs) and undergo rapid acellular mineralization when incorporated with bioactive glass particles, both in vitro and subcutaneously in vivo. However, the potential of DC-bioactive glass hybrid gels in delivering DPSCs for bone regeneration in an osseous site has not been investigated. In this study, the efficacies of both acellular and DPSC-seeded DC-S53P4 bioactive glass [(53)SiO₂-(23)Na₂O-(20)CaO-(4)P₂O₅, wt%] hybrid gels were investigated in a critical-sized murine calvarial defect. The incorporation of S53P4, an osteostimulative bioactive glass, into DC gels led to its accelerated acellular mineralization in simulated body fluid (SBF), in vitro, where hydroxycarbonated apatite was detected within 1 day. By day 7 in SBF, micro-mechanical analysis demonstrated an 8-fold increase in the compressive modulus of the mineralized gels. The in-situ effect of the bioactive glass on human-DPSCs within DC-S53P4 was evident, by their osteogenic differentiation in the absence of osteogenic supplements. The production of alkaline phosphatase and collagen type I was further increased when cultured in osteogenic media. This osteostimulative effect of DC-S53P4 constructs was confirmed in vivo, where after 8 weeks implantation, both acellular scaffolds and DPSC-seeded DC-S53P4 constructs formed mineralized and vascularized bone matrices with osteoblastic and osteoclastic cell activity. Surprisingly, however, in vivo micro-CT analysis confirmed that the acellular scaffolds generated larger volumes of bone, already visible at week 3 and exhibiting superior trabecular architecture. The results of this study suggest that DC-S53P4 scaffolds negate the need for stem cell delivery for effective bone tissue regeneration and may expedite their path towards clinical applications.

Bone-Selective MRI as a Nonradiative Alternative to CT for Craniofacial Imaging

RATIONAL AND OBJECTIVES

Computed tomography (CT) is the clinical gold-standard for high-resolution 3D visualization of cortical bone structures. However, ionizing radiation is of concern, particularly for pediatric patients. This study evaluates the feasibility of producing 3D human skull renderings using a novel bone-selective magnetic resonance imaging technique.

MATERIALS AND METHODS

A dual-radiofrequency pulse, dual-echo, 3D ultrashort echo time sequence was applied for scanning of a cadaver skull and five healthy adult subjects. Scans were each completed within 6 minutes. Semiautomatic segmentation of bone voxels was performed using ITK-SNAP software, leading to 3D renderings of the skulls. For comparison, thin-slice head CT scans were performed. Mimics software was used to measure eight anatomic distances from 3D renderings. Lin's Concordance Correlation test was applied to assess agreement between measurements from MR-based and CT-based 3D skull renderings.

RESULTS

The 3D rendered MR images depict most craniofacial features (e.g., zygomatic arch), although some voxels were erroneously included or excluded in the renderings. MR-based measurements differed from CT-based measurements by mean percent difference ranging from 2.3%-5.0%. Lin's Concordance Correlation Coefficients for MR-based vs CT-based measurements ranged from 0.998-1.000.

CONCLUSION

The proposed dual-radiofrequency dual-echo 3D ultrashort echo time imaging technique produces high-resolution bone-specific images within a clinically feasible imaging time, leading to clear visualization of craniofacial skeletal structures. Concordance coefficients suggest good reliability of the method compared to CT. The method is currently limited by time and manual input necessary for segmentation correction. Further investigation is needed for more accurate 3D renderings and for scanning of pediatric patients.

Multifactorial Genetic and Environmental Hedgehog Pathway Disruption Sensitizes Embryos to Alcohol-Induced Craniofacial Defects

BACKGROUND

Prenatal alcohol exposure (PAE) is perhaps the most common environmental cause of human birth defects. These exposures cause a range of structural and neurological defects, including facial dysmorphologies, collectively known as fetal alcohol spectrum disorders (FASD). While PAE causes FASD, phenotypic outcomes vary widely. It is thought that multifactorial genetic and environmental interactions modify the effects of PAE. However, little is known of the nature of these modifiers. Disruption of the Hedgehog (Hh) signaling pathway has been suggested as a modifier of ethanol teratogenicity. In addition to regulating the morphogenesis of craniofacial tissues commonly disrupted in FASD, a core member of the Hh pathway, Smoothened, is susceptible to modulation by structurally diverse chemicals. These include environmentally prevalent teratogens like piperonyl butoxide (PBO), a synergist found in thousands of pesticide formulations.

METHODS

Here, we characterize multifactorial genetic and environmental interactions using a zebrafish model of craniofacial development.

RESULTS

We show that loss of a single allele of shha sensitized embryos to both alcohol- and PBO-induced facial defects. Co-exposure of PBO and alcohol synergized to cause more frequent and severe defects. The effects of this co-exposure were even more profound in the genetically susceptible shha heterozygotes.

CONCLUSIONS

Together, these findings shed light on the multifactorial basis of alcohol-induced craniofacial defects. In addition to further implicating genetic disruption of the Hh pathway in alcohol teratogenicity, our findings suggest that co-exposure to environmental chemicals that perturb Hh signaling may be important variables in FASD and related craniofacial disorders.

DIVA, a 3D virtual reality platform, improves undergraduate craniofacial trauma education

Craniofacial fractures management is challenging to teach due to the complex anatomy of the head, even when using three-dimensional CT-scan images. DIVA is a software allowing the straightforward visualization of CT-scans in a user-friendly three-dimensional virtual reality environment. Here, we assess DIVA as an educational tool for craniofacial trauma for undergraduate medical students. Three craniofacial trauma cases (jaw fracture, naso-orbital-ethmoid complex fracture and Le Fort 3 fracture) were submitted to 50 undergraduate medical students, who had to provide diagnoses and treatment plans. Each student then filled an 8-item questionnaire assessing satisfaction, potential benefit, ease of use and tolerance. Additionally, 4 postgraduate students were requested to explore these cases and to place 6 anatomical landmarks on both virtual reality renderings and usual slice-based three-dimensional CT-scan visualizations. High degrees of satisfaction (98%) without specific tolerance issues (86%) were reported. The potential benefit in a better understanding of craniofacial trauma using virtual reality was reported by almost all students (98%). Virtual reality allowed a reliable localization of key anatomical landmarks when compared with standard three-dimensional CT-scan visualization. Virtual reality interfaces such DIVA are beneficial to medical students for a better understanding of craniofacial trauma and allow a reliable rendering of craniofacial anatomy.

Effects of electrostimulation therapy in facial nerve palsy

Facial palsy (FP) is a functional disorder of the facial nerve involving paralysis of the mimic muscles. According to the principle “time is muscle,” early surgical treatment is tremendously important for preserving the mimic musculature if there are no signs of nerve function recovery. In a 49-year-old female patient, even 19 months after onset of FP, successful neurotization was still possible by a V-to-VII nerve transfer and cross-face nerve grafting. Our patient suffered from complete FP after vestibular schwannoma surgery. With continuous application of electrostimulation (ES) therapy, the patient was able to bridge the period between the first onset of FP and neurotization surgery. The significance of ES for mimic musculature preservation in FP patients has not yet been fully clarified. More attention should be paid to this form of therapy in order to preserve the facial musculature, and its benefits should be evaluated in further prospective clinical studies.

Genetic background dependent modifiers of craniosynostosis severity

Craniosynostosis severity varies in patients with identical genetic mutations. To understand causes of this phenotypic variation, we backcrossed the FGFR2^+/C342Y mouse model of Crouzon syndrome onto congenic C57BL/6 and BALB/c backgrounds. Coronal suture fusion was observed in C57BL/6 (88% incidence, p < .001 between genotypes) but not in BALB/c FGFR2^+/C342Y mutant mice at 3 weeks after birth, establishing that that the two models differ in phenotype severity. To begin identifying pre-existing modifiers of craniosynostosis severity, we compared transcriptome signatures of cranial tissues from C57BL/6 vs. BALB/c FGFR2^+/+ mice. We separately analyzed frontal bone with coronal suture tissue from parietal bone with sagittal suture tissues because the coronal suture but not the sagittal suture fuses in FGFR2^+/C342Y mice. The craniosynostosis associated Twist and En1 transcription factors were down-regulated, while Runx2 was up-regulated, in C57BL/6 compared to BALB/c tissues, which could predispose to craniosynostosis. Transcriptome analyses under the GO term MAPK cascade revealed that genes associated with calcium ion channels, angiogenesis, protein quality control and cell stress response were central to transcriptome differences associated with genetic background. FGFR2 and HSPA2 protein levels plus ERK1/2 activity were higher in cells isolated from C57BL/6 than BALB/c cranial tissues. Notably, the HSPA2 protein chaperone is central to craniofacial genetic epistasis, and we find that FGFR2 protein is abnormally processed in primary cells from FGFR2^+/C342Y but not FGFR2^+/+ mice. Therefore, we propose that differences in protein quality control responses may contribute to genetic background influences on craniosynostosis phenotype severity.

Giant craniofacial osteoma with orbital invasion

Craniofacial osteomas, which involve orbits, can cause several problems, such as displacement of the globe, diplopia, and refractive changes. We report the case of a young man with diplopia and blurred vision, with a giant osteoma occupying right frontal and ethmoid sinuses, encroaching into his right orbit. The symptoms resolved 3 months after surgery. Our case highlights the successful surgery for a symptomatic craniofacial osteoma with orbital invasion.

Migratory patterns and evolutionary plasticity of cranial neural crest cells in ray-finned fishes

The cranial neural crest (CNC) arises within the developing central nervous system, but then migrates away from the neural tube in three consecutive streams termed mandibular, hyoid and branchial, respectively, according to the order along the anteroposterior axis. While the process of neural crest emigration generally follows a conserved anterior to posterior sequence across vertebrates, we find that ray-finned fishes (bichir, sterlet, gar, and pike) exhibit several heterochronies in the timing and order of CNC emergence that influences their subsequent migratory patterns. First, emigration of the cranial neural crest in these fishes occurs prematurely compared to other vertebrates, already initiating during early neurulation and well before neural tube closure. Second, delamination of the hyoid stream occurs prior to the more anterior mandibular stream; this is associated with early morphogenesis of key hyoid structures like external gills (bichir), a large opercular flap (gar) or first forming cartilage (pike). In sterlet, the hyoid and branchial CNC cells form a single hyobranchial sheet, which later segregates in concert with second pharyngeal pouch morphogenesis. Taken together, the results show that despite generally conserved migratory patterns, heterochronic alterations in the timing of emigration and pattern of migration of CNC cells accompanies morphological diversity of ray-finned fishes.

Interaction of the craniofacial complex and velopharyngeal musculature on speech resonance in children with 22q11.2 deletion syndrome: An MRI analysis

There are limited MRI studies of craniofacial and velopharyngeal features in children with 22q11.2 deletion syndrome (22q11.2DS) and to date, none have explored the potential relationship between these features and the speech phenotype. The purpose of this study was to examine the relationship between craniofacial and related velopharyngeal structures in children with 22q11.2DS and to assess their correlation to resonance features using an unsedated MRI protocol. Fifteen children with 22q11.2DS and 15 age- and sex-matched controls with normal velopharyngeal anatomy (ages 4-12 years) successfully completed the study. Analysis of covariance was used to compare differences between the experimental (22q11.2DS) and control (children with normal anatomy) groups. Correlation analyses and regression models were also utilized. The 22q11.2DS group demonstrated significantly shorter nasion-to-sella, sella-to-basion, and basion-to-opisthion distances. The anterior cranial base angle was significantly more obtuse. The levator veli palatini (levator) muscle was significantly thinner and shorter, with an obtuse angle of origin in the 22q11.2DS group. Levator length was significantly correlated with the sella-to-basion measure and hypernasality was correlated with levator origin-to-origin distance. Preliminary results from this study indicate a significant association between hypernasality and levator origin-to-origin distance. Findings from the present study, provide an insight into the pathophysiology of velopharyngeal dysfunction related to this clinically complex population.