Management of squamous cell carcinomas of the skull-base

PURPOSE

The purpose of this review is to assess the recent evidence regarding the management of squamous cell carcinoma of the skull-base and to discuss the implications of these findings on clinical practice.

METHOD

Free text Medline and MeSH term search of publications relating to Squamous Cell Carcinoma & Skull-base and Skull base, Neoplasm respectively. Multidisciplinary clinical guidelines were also reviewed.

RESULTS

The primary search yielded a total of 271 papers which following initial review was reduced to 28. Secondary search yielded 56 papers. There were no randomised controlled trials relating to squamous cell carcinoma of the skull-base and as such this review is based on cohort studies, case series and expert opinion.

CONCLUSION

Squamous cell carcinoma (SCC) is the most common cancer occurring in the Head and Neck. Squamous cell carcinoma is also the most common cancer arising within the nose and sinuses of which skull-base squamous cell carcinoma is a rare subgroup. Evidence relating to the management and survival of skull-base SCC is based on expert opinion and. retrospective analyses Clinical examination and biopsy, imaging and a broad multidisciplinary team are key to the management of skull-base SCC. The information gathered should be used to guide informed discussion by suitably trained experts with patients regarding surgical approach, post-operative recovery and adjuvant or neoadjuvant treatments. The standard of care is currently to perform skull base resection with or without additional craniotomy, pedicled or free flap reconstruction in multiple layers and post-operative radiation (usually photons or protons). Open approaches have traditionally been the mainstay, however in certain cases endoscopic approaches can yield equivalent results and offer many advantages. Despite advances in care survival remains poor with a nearly one in five risk of nodal recurrence within two years.

Differential cellular proliferation underlies heterochronic generation of cranial diversity in phyllostomid bats

Background

Skull diversity in the neotropical leaf-nosed bats (Phyllostomidae) evolved through a heterochronic process called peramorphosis, with underlying causes varying by subfamily. The nectar-eating (subfamily Glossophaginae) and blood-eating (subfamily Desmondontinae) groups originate from insect-eating ancestors and generate their uniquely shaped faces and skulls by extending the ancestral ontogenetic program, appending new developmental stages and demonstrating peramorphosis by hypermorphosis. However, the fruit-eating phyllostomids (subfamilies Carollinae and Stenodermatinae) adjust their craniofacial development by speeding up certain developmental processes, displaying peramorphosis by acceleration. We hypothesized that these two forms of peramorphosis detected by our morphometric studies could be explained by differential growth and investigated cell proliferation during craniofacial morphogenesis.

Results

We obtained cranial tissues from four wild-caught bat species representing a range of facial diversity and labeled mitotic cells using immunohistochemistry. During craniofacial development, all bats display a conserved spatiotemporal distribution of proliferative cells with distinguishable zones of elevated mitosis. These areas were identified as modules by the spatial distribution analysis. Ancestral state reconstruction of proliferation rates and patterns in the facial module between species provided support, and a degree of explanation, for the developmental mechanisms underlying the two models of peramorphosis. In the long-faced species, Glossophaga soricina, whose facial shape evolved by hypermorphosis, cell proliferation rate is maintained at lower levels and for a longer period of time compared to the outgroup species Miniopterus natalensis. In both species of studied short-faced fruit bats, Carollia perspicillata and Artibeus jamaicensis, which evolved under the acceleration model, cell proliferation rate is increased compared to the outgroup.

Conclusions

This is the first study which links differential cellular proliferation and developmental modularity with heterochronic developmental changes, leading to the evolution of adaptive cranial diversity in an important group of mammals.

The use of 3D printing technology in the creation of patient-specific facial prostheses

BACKGROUND

Personalised medicine aims to optimise patient outcomes by tailoring treatments and interventions to the individual. While this approach can offer a number of benefits, it can be accompanied by significant overheads in terms of resources. Prostheses exist in order to restore and replicate the normal functions and appearance of the body but if these are not individually tailored to the patient's needs then a true restoration cannot be fully achieved. Traditionally a labour intensive process, the fabrication of craniofacial prostheses, involves taking a plaster cast of the area to be treated, hand carving wax models of the restoration and multiple meetings with the patient to alter this wax restoration before making a final prosthesis in silicone.

AIMS

Utilising the patient's pre-existing computed tomography (CT) images and 3D printing technology, a patient-specific prosthesis can be created with improved efficiency and accuracy.

METHODS

This study demonstrates methods used to create a patient-specific orbital prosthesis using CT images. These images were manipulated in a way which allowed for the intact orbit to be mirrored and used to develop a 3D printed model which acted as the starting point to create a silicone prosthesis.

RESULTS

The benefits of using this method include reduced manufacturing time, decreased outpatient appointments, improved personalised outcomes and a repeatable process allowing multiple prostheses to be made.

CONCLUSIONS

3D printing is a valuable tool which can provide significant savings in time and improve patient outcomes by offering a tailored approach to each individual's treatment.

Hemorrhagic Fibrous Dysplasia with Acute Neurological Decline: Case Report and Review of the Literature

BACKGROUND

Fibrous dysplasia is a rare, benign fibro-osseous malformation whose occurrence in the craniofacial area can result in optic nerve compression, a cerebral mass effect, and cosmetic deformity. Most lesions will progress slowly, and the risk of malignant progression is rare.

CASE DESCRIPTION

We present the case of a 21-year-old woman who had presented with acute worsening visual loss secondary to hemorrhagic fibrous dysplasia with ensuing optic nerve compression. Emergent surgical decompression resulted in rapid improvement of her visual dysfunction. The pathological features demonstrated a mixed pattern of woven bone in a fibrous background and secondary aneurysmal bone cyst-like changes.

CONCLUSIONS

Hemorrhagic transformation of craniofacial FD remains rare but can present with acute neurologic deterioration. Rapid diagnosis and treatment can allow reversal of patient morbidity. We have also included Supplementary Video 1 to illustrate the surgical principles, and we review the reported data of similar cases.

Properties of neurons in the superficial laminae of trigeminal nucleus caudalis

The trigeminal nucleus caudalis (TNc) receives extensive afferent innervation from peripheral sensory neurons of the trigeminal ganglion (TG), and is the first central relay in the circuitry underpinning orofacial pain. Despite the initial characterization of the neurons in the superficial laminae, many questions remain. Here we report on electrophysiological properties of 535 superficial lamina I/II TNc neurons. Based on their firing pattern, we assigned these cells to five main groups, including (1) tonic, (2) phasic, (3) delayed, (4) H‐current, and (5) tonic‐phasic neurons, groups that exhibit distinct intrinsic properties and share some similarity with groups identified in the spinal dorsal horn. Driving predominantly nociceptive TG primary afferents using optogenetic stimulation in TRPV1/ChR2 animals, we found that tonic and H‐current cells are most likely to receive pure monosynaptic input, whereas delayed neurons are more likely to exhibit inputs that appear polysynaptic. Finally, for the first time in TNc neurons, we used unsupervised clustering analysis methods and found that the kinetics of the action potentials and other intrinsic properties of these groups differ significantly from one another. Unsupervised spectral clustering based solely on a single voltage response to rheobase current was sufficient to group cells with shared properties independent of action potential discharge pattern, indicating that this approach can be effectively applied to identify functional neuronal subclasses. Together, our data illustrate that cells in the TNc with distinct patterns of TRPV1/ChR2 afferent innervation are physiologically diverse, but can be understood as a few major groups of cells having shared functional properties.

Septopreoptic holoprosencephaly in intracranial abnormalities: an under-diagnosed midline finding

BACKGROUND

Septopreoptic holoprosencephaly is a mild form of holoprosencephaly in which the midline non-separation is restricted to the septal or preoptic regions. This entity has only been described in a small case series in which associated intracranial abnormalities were limited to the midline structures.

OBJECTIVE

To describe the radiologic findings of septopreoptic holoprosencephaly and highlight that it can be associated with a variety of intracranial abnormalities, not merely with abnormalities restricted to midline structures as previously reported.

MATERIALS AND METHODS

We retrospectively identified 22 children whose MRIs were confirmed to have non-separation restricted to the septal and preoptic region, fulfilling the criteria for septopreoptic holoprosencephaly. We then categorized MRIs as having, in addition, either intracranial abnormalities limited to the midline structures or major abnormalities not limited to the midline structures.

RESULTS

Five children had intracranial abnormalities limited to the midline structures. Seventeen children had major intracranial abnormalities not limited to the midline structures. The major abnormalities included: patterning defects of the midbrain-hindbrain (elongated midbrain, shortened pons, shortened/elongated medulla, partial rhombencephalosynapsis), bilateral perisylvian polymicrogyria, microcephaly, megalencephaly and a spheno-ethmoidal encephalocele. Recognized syndromes/chromosomal abnormalities were also observed in this patient group.

CONCLUSION

Our results suggest that septopreoptic holoprosencephaly has been under-recognized and under-reported to date. We propose that searching for this anomaly should be part of the complete assessment of the midline in all children undergoing brain MRI for intracranial malformations.

A review of genetics of nasal development and morphological variation

The nose is central in the determination of facial esthetics. The variations in its structural characteristics greatly influence the ultimate dentoskeletal positioning at the end of an orthodontic therapy. A careful insight into its developmental etiology will greatly aid the health care professional in identifying patient's real concern about the facial appearance. This in turn will aid in the fabrication of a better treatment plan regarding the end placement goals for the teeth and jaws in all the three dimensions of space. However, this important structure is often missed as a part of the diagnostic and treatment planning regime owing to the lack of meticulous understanding of its developmental etiology by the orthodontists. The development of the nose in the embryo occurs in pre skeletal and skeletal phases by a well-coordinated and regulated interaction of multiple signaling cascades with the crucial importance of each factor in the entire mechanism. The five key factors, which control frontonasal development are sonic hedgehog (SHH), fibroblast growth factors (FGF), transforming growth factor β (TGFβ), wingless (WNT) proteins, and bone morphogenetic protein (BMP). The recent evidence suggests the association of various nasal dimensions and their related syndromes with multiple genes. The revelation of nasal genetic makeup in totality will aid in ascertaining the direction of growth, which will govern our orthodontic treatment results and will also act as a harbinger for potential genetic editing and tissue engineering. This article describes at length the morphological and genetic aspect of nasal growth and development in light of the gender and racial variability along with the emphasis on the importance of knowing these nasal features with regard to diagnosis and treatment planning in orthodontics.

Obturation and Tissue Transfer for Large Craniofacial Defects

Reconstruction of large craniofacial defects requires several factors to be considered before deciding on the best reconstructive option. This article discusses various factors taken into consideration when deciding on which reconstructive option is ideal for a given patient and defect. For large craniofacial defects, reconstruction using tissue transfer is considered preferentially over obturation, although in select defects obturation using a traditional tooth- or implant-borne prosthetic obturator can be considered a viable option.

Craniofacial and neck burns in the pediatric population

INTRODUCTION

Burn injuries can present with catastrophic physical and psychiatric harm with extensive, long-term sequelae. The pediatric population may especially be at-risk given this population's early neurocognitive and behavioral state of development. Innovations in treatment modalities and the development of evidence-based guidelines have helped mitigate burn morbidity and mortality in the pediatric population. Unfortunately, a surprising dearth of literature identifies risk-factors, epidemiological data, injury mechanisms, and prognostic factors within the pediatric population in the setting of craniofacial burns.

METHODS

An analysis of emergency department visits under the National Electronic Injury Surveillance System was conducted for the most recent 5-year period available (2014-2018). Available information includes demographical data, such as age and sex, mechanism of injury, visit circumstances, as well as visit disposition. Additionally, details surrounding the injury, including type of burn and anatomical location of injury, were compared.

RESULTS

After a review of results, a total of 2599 patients were included for analysis. Our study shows that infants and young children are at increased risk for grave injury 27.3% and 13% of infants and toddlers transferred or admitted, respectively, p < 0.05). 59.8% of infant burns in particular were caused by liquid or kitchen products, while 44.5% of burns in toddlers were caused by chemical products (p < 0.05 for both). Conversely, adolescents are at greater risk of burns in the setting of occupational and hobby-based activities (20.4% of adolescent burns).

CONCLUSIONS

Craniofacial burns in the pediatric population may present with complex pathology and sometimes necessitate advanced care. Presentations and prognoses are different dependent upon age and injury mechanism. These findings may serve as important framework in the establishment of guidelines for medical and legislative reform.

Relationship between vertical facial pattern and brain structure and shape

OBJECTIVES

Dolichofacial (long-faced) and brachyfacial (short-faced) individuals show specific and well-differentiated craniofacial morphology. Here, we hypothesise that differences in the basicranial orientation and topology between dolicho- and brachyfacial subjects could be associated with differences in the supporting brain tissues.

MATERIAL AND METHODS

Brain volumes (total intracranial, grey matter, and white matter volume), cortical thickness, and the volumes and shapes of fifteen subcortical nuclei were assessed on the basis of magnetic resonance imaging in 185 subjects. Global, voxel-wise and shape analyses, as well as multiple regression models, were generated to evaluate the association between vertical facial variations (dolicho- and brachyfacial spectrum) and brain morphology.

RESULTS

Several differences in brain anatomy between dolicho- and brachyfacial subjects, along with relevant associations between vertical facial indices and brain structure and shape, were found. The most relevant finding of this study is related to the strong association of vertical facial indices with the volumes and shapes of subcortical nuclei, as the dolichofacial pattern increased, the bilateral hippocampus and brain stem expanded, while the left caudate, right pallidus, right amygdala, and right accumbens decreased in volume.

CONCLUSIONS

Long- and short-faced human subjects present differences in brain structure and shape.

CLINICAL SIGNIFICANT

The results of our study increase the clinician's knowledge about brain structure in dolicho- and brachyfacial patients. The findings could be of interest since the affected brain areas are involved in higher cognitive functions in humans, including language, memory, and attention.

The conserved and divergent roles of Prdm3 and Prdm16 in zebrafish and mouse craniofacial development

The formation of the craniofacial skeleton is a highly dynamic process that requires proper orchestration of various cellular processes in cranial neural crest cell (cNCC) development, including cell migration, proliferation, differentiation, polarity and cell death. Alterations that occur during cNCC development result in congenital birth defects and craniofacial abnormalities such as cleft lip with or without cleft palate. While the gene regulatory networks facilitating neural crest development have been extensively studied, the epigenetic mechanisms by which these pathways are activated or repressed in a temporal and spatially regulated manner remain largely unknown. Chromatin modifiers can precisely modify gene expression through a variety of mechanisms including histone modifications such as methylation. Here, we investigated the role of two members of the PRDM (Positive regulatory domain) histone methyltransferase family, Prdm3 and Prdm16 in craniofacial development using genetic models in zebrafish and mice. Loss of prdm3 or prdm16 in zebrafish causes craniofacial defects including hypoplasia of the craniofacial cartilage elements, undefined posterior ceratobranchials, and decreased mineralization of the parasphenoid. In mice, while conditional loss of Prdm3 in the early embryo proper causes mid-gestation lethality, loss of Prdm16 caused craniofacial defects including anterior mandibular hypoplasia, clefting in the secondary palate and severe middle ear defects. In zebrafish, prdm3 and prdm16 compensate for each other as well as a third Prdm family member, prdm1a. Combinatorial loss of prdm1a, prdm3, and prdm16 alleles results in severe hypoplasia of the anterior cartilage elements, abnormal formation of the jaw joint, complete loss of the posterior ceratobranchials, and clefting of the ethmoid plate. We further determined that loss of prdm3 and prdm16 reduces methylation of histone 3 lysine 9 (repression) and histone 3 lysine 4 (activation) in zebrafish. In mice, loss of Prdm16 significantly decreased histone 3 lysine 9 methylation in the palatal shelves but surprisingly did not change histone 3 lysine 4 methylation. Taken together, Prdm3 and Prdm16 play an important role in craniofacial development by maintaining temporal and spatial regulation of gene regulatory networks necessary for proper cNCC development and these functions are both conserved and divergent across vertebrates.

Fronto-orbital advancement and reconstruction using reverse frontal bone graft without the use of orbital bar: a technical note

INTRODUCTION

We describe our technique of using reverse frontal bone graft for FOAR for patients with metopic or coronal synostosis and present our complications using the Leeds classification system for complications in craniosynostosis surgery.

METHODS

Since April 2015, seventeen patients have been operated using this technique. We perform a frontal bone graft that is then reversed, and supraorbital margins are drilled out. The orbital bar is then removed and drilled down to make bone dust and on-lay bone grafts which are then used to fill gaps on exposed dura and fill in around the temporal region.

RESULTS

All 17 patients who underwent this technique have good cosmetic results. We report 5 (29%) complications and 8 (47%) blood transfusions (7 exposures, 1 cell salvage).

Metastatic thyroid carcinoma presented as a large craniofacial mass: Case report and CT findings

Cranial metastases are uncommon locations of thyroid papillary carcinoma. They significantly reduce patients’ survival, especially in a context of late management. We report the case of a 46-year-old woman who presented an anterior cervical swelling, then a progressive large craniofacial mass for more than 5 years without any treatment. The imaging performed showed a large craniofacial tissue mass with frontotemporal and right orbital bone destruction extended to the face sinuses and the underlying extradural space without brain involvement; the second thyroid tumor right site had similar imaging characteristics to the cranial mass. The diagnosis of papillary carcinoma with craniofacial metastasis was retained after cranial biopsy and thyroid cytology. At this stage, a cranial surgery has not been proposed but a palliative hormonal treatment. The patient died 2 weeks after diagnosis. This case illustrates the relevant role of imaging in the assessment of thyroid tumors and the value of early management for improving patients’ survival.

Utilization of contrast-enhanced ultrasound in the evaluation of craniofacial osseous lesions: A case report

A 14-year-old boy undergoing brain MRI had an incidental avidly enhancing lobulated lesion in the left superolateral orbital rim with associated cortical erosion. Apart from Contrast-enhanced Magnetic Resonance Imaging (MRI), and Computed Tomography (CT), Contrast-Enhanced Ultrasound (CEUS) was obtained prior to a biopsy. It provided additional information about the microvasculature and an orbital biopsy was subsequently performed through an upper eyelid crease incision with minimal blood loss and no postoperative complications. Histopathological examination revealed features which were compatible with the diagnosis of LCH. The authors propose that CEUS may be considered as an adjunct and possibly alternative imaging modality for the evaluation of craniofacial osseous lesions, especially in the orbital region (due to the known radio-sensitivity of the eyes) and in pediatric patients, to minimize the risk of ionizing-radiation exposure.

Primary osteogenic sarcoma of the skull: Report of two cases with review of literature

Primary calvarial (excluding jaw) osteosarcoma is rare. We report two cases highlighting their unusual presentation and histopathologic variability – a 30-year-old female who presented with progressively increasing headache and a rapidly growing frontal swelling and a 16-year-old girl who had a rapidly growing mass in the left frontoparietal region which had recurred thrice but was otherwise asymptomatic. The lesions were osteolytic on neuroimaging and histopathological examination confirmed osteosarcoma. These two unusual cases are discussed along with a brief review of literature.

Paediatric oral & maxillofacial surgery

Children have differences in their physiology, anatomy and they are continuing to grow and develop. The management of pathology, trauma, deformity and upper airway obstruction in the young growing patient has to take into account these factors in the treatment planning for these conditions. It is important for Oral & Maxillofacial Surgeons to understand the potential impact of disease or injury on the developing facial skeleton and dentition. This chapter will provide an overview of the some of the major components of paediatric maxillofacial surgery and their management.

Craniofacial Interventions in Children

Craniofacial interventions are common and the surgical options continue to grow. The issues encountered include micrognathia, macroglossia, midface hypoplasia, hearing loss, facial nerve palsy, hemifacial microsomia, and microtia. In addition, a unifying theme is complex upper airway obstruction. Throughout a child's life the focus of interventions may change from airway management to speech, hearing, and language optimization, and finally to decannulation and procedures aimed at social integration and self-esteem. Otolaryngologists play an important role is this arena and provide high-quality care while continuing to expand what can be done for our patients.

Obstructive sleep apnea and craniofacial appearance in MPS type I-Hurler children after hematopoietic stem cell transplantation

OBJECTIVES

Mucopolysaccharidosis type I (MPS I) is an inherited lysosomal storage disorder characterized by severe multi-systemic organ manifestations including obstructive sleep apnea syndrome (OSAS). Hematopoietic stem cell transplantation (HSCT) is the treatment of choice in severe MPS I (MPS IH, Hurler syndrome). However, the effect of HSCT on OSAS in MPS IH still remains unclear. The purpose of this study was to analyze respiratory patterns during sleep following HSCT in MPS IH children and to relate these findings to craniofacial abnormalities.

METHODS

Overnight polysomnographies of nine MPS IH children (mean age: 8.2 years) previously treated with HSCT were retrospectively analyzed. Magnetic resonance images of the head were assessed with regard to soft and hard tissue abnormalities of the upper respiratory tract.

RESULTS

The mean apnea hypopnea index (AHI) was 5.3 events/h (range, 0.3-12.2), and the majority of apnea/hypopneas were obstructive. Whereas two patients had severe OSAS (AHI > 10) and two moderate OSAS (5 > AHI < 10), five patients had no evidence of OSAS (AHI < 2.0). Donor cell chimerism was significantly lower in MPS IH patients with OSAS as compared to patients without OSAS (p < 0.001). The upper airway space and the maxilla were significantly smaller and the adenoids larger in MPS IH patients with OSAS as compared to those of non-OSAS patients.

CONCLUSION

OSAS was only observed in MPS IH patients with graft failure or low donor cell chimerism. Conversely, successful HSCT seems to ameliorate adenoid hyperplasia and maxillary constriction in MPS IH patients and thereby minimizes the risk of OSAS at least at younger ages.

In the line-up: deleted genes associated with DiGeorge/22q11.2 deletion syndrome: are they all suspects?

BACKGROUND

22q11.2 deletion syndrome (22q11DS), a copy number variation (CNV) disorder, occurs in approximately 1:4000 live births due to a heterozygous microdeletion at position 11.2 (proximal) on the q arm of human chromosome 22 (hChr22) (McDonald-McGinn and Sullivan, Medicine 90:1-18, 2011). This disorder was known as DiGeorge syndrome, Velo-cardio-facial syndrome (VCFS) or conotruncal anomaly face syndrome (CTAF) based upon diagnostic cardiovascular, pharyngeal, and craniofacial anomalies (McDonald-McGinn and Sullivan, Medicine 90:1-18, 2011; Burn et al., J Med Genet 30:822-4, 1993) before this phenotypic spectrum was associated with 22q11.2 CNVs. Subsequently, 22q11.2 deletion emerged as a major genomic lesion associated with vulnerability for several clinically defined behavioral deficits common to a number of neurodevelopmental disorders (Fernandez et al., Principles of Developmental Genetics, 2015; Robin and Shprintzen, J Pediatr 147:90-6, 2005; Schneider et al., Am J Psychiatry 171:627-39, 2014).

RESULTS

The mechanistic relationships between heterozygously deleted 22q11.2 genes and 22q11DS phenotypes are still unknown. We assembled a comprehensive "line-up" of the 36 protein coding loci in the 1.5 Mb minimal critical deleted region on hChr22q11.2, plus 20 protein coding loci in the distal 1.5 Mb that defines the 3 Mb typical 22q11DS deletion. We categorized candidates based upon apparent primary cell biological functions. We analyzed 41 of these genes that encode known proteins to determine whether haploinsufficiency of any single 22q11.2 gene-a one gene to one phenotype correspondence due to heterozygous deletion restricted to that locus-versus complex multigenic interactions can account for single or multiple 22q11DS phenotypes.

CONCLUSIONS

Our 22q11.2 functional genomic assessment does not support current theories of single gene haploinsufficiency for one or all 22q11DS phenotypes. Shared molecular functions, convergence on fundamental cell biological processes, and related consequences of individual 22q11.2 genes point to a matrix of multigenic interactions due to diminished 22q11.2 gene dosage. These interactions target fundamental cellular mechanisms essential for development, maturation, or homeostasis at subsets of 22q11DS phenotypic sites.

Avenues for Investigating the Neural Crest and Its Derivatives in Non-model (Unconventional) Vertebrates: A Craniofacial Skeleton Perspective

One of the early, profound insights regarding the biology of the neural crest was the observation of its contribution to the skeletal structures of the cranium and jaws. The critical nature of these structures made the comparative analysis of the cranial neural crest and its derived structures essential investigative aims toward our understanding of the development and evolution of vertebrates and vertebrate-specific structures. Though classically applied to a relatively wide range of taxa in the nineteenth and early twentieth centuries, the application of traditional methodologies for complex comparative developmental and anatomical analyses subsequently become more limited by their time-consuming nature, resource scarcity, and a greater emphasis on the genetic and molecular regulation of patterning and morphogenesis in a select number of tractable model organisms. Recently, however, this trend has been reversed, and the value of genetic and molecular-based questions applied to non-model (unconventional) vertebrate organisms has been re-appreciated. This is particularly true of comparative investigations of cranial neural crest biology. Herein, we present methodologies for the analysis of the cranial neural crest and its structural derivatives employable in modern investigations of both model and unconventional vertebrate organisms.

Drainage outflow restriction as a parameter associated with cortical venous reflux in craniofacial arteriovenous malformations with cavernous sinus drainage

PURPOSE

Craniofacial arteriovenous malformations (CF-AVMs) are locally aggressive extracranial lesions. When CF-AVMs involve cavernous sinus (CS) as their draining vein, they represent a special subgroup which may interfere intracranial venous system. In this study, we aimed to analyze the venous drainage patterns of CF-AVMs with CS drainage and to demonstrate how it affected our treatment strategy.

METHODS

Cases of CF-AVMs associated with CS drainage were collected from a prospectively collected database of patients with CF-AVMs who underwent endovascular treatment from September 2016 to March 2018. Clinical data and angioarchitectural findings were analyzed. Factors associated with the presence of venous reflux (cortical venous reflux (CVR) or dural sinus reflux (DSR)) were analyzed.

RESULTS

Fifteen CF-AVM patients associated with CS drainage were analyzed. Three cases of venous reflux from the CS were identified (CVR, 2; DSR, 1). Lesions with unilateral venous drainage, ≤ 2 draining veins, and the absence of antegrade CS outflow were more likely to develop venous reflux from the CS. We successfully performed additional trans-venous coil embolization of the superior ophthalmic vein in two patients with malformations associated with venous reflux to close this venous connection to the CS.

CONCLUSION

CF-AVMs associated with CS drainage confer an increased risk of CVR and DSR, especially in cases where the drainage outflow is restricted. Identification of this venous angioarchitecture is essential in the evaluation and treatment planning of CF-AVMs.

Maxillofacial Injuries in Motorcyclists Following the Implementation of Helmet

Background:

It has been reported that 20%–60% of all people injured in road traffic accidents (RTAs) tend to have some form of maxillofacial injury. Mangalore city, Karnataka State, India, traffic police has enforced the law to wear helmets to tackle the problem. The outcome of the initiative till date was not measured. Therefore, the objective of the study was to assess the prevalence of maxillofacial injuries among the victims of motorized two-wheeler RTAs, following the passing of the helmet law.

Materials and Methods:

The study was conducted at the Accident and Emergency Department of K.S. Hegde Medical College and Hospital and at the Department of Oral and Maxillofacial Surgery, A.B. Shetty Memorial Institute of Dental Sciences, Nitte (Deemed to be University), Mangalore, Karnataka, India. The inclusion criteria were the patients who had two-wheeler accidents during the time period of 2016–2017 was collected. The data related to age, gender, helmet wearing, diagnosis, and type of orthopedic injuries was included. A descriptive statistics was calculated along with 95% confidence interval; correlation coefficient and odds ratio using STATA software.

Results:

A total of N = 347 individuals were included in the study. The mean age of the individuals was 33.7 (2–85) years, and the median age was 32 years. 81.55% (N = 283) were male and 18.44% (N = 64) were female. Among the individuals, 51.5% (N = 179) were not wearing helmets and 44.38% (N = 154) of them were males. A total of 25.07 (N = 87) individuals had orthopedic injuries and 16.42% (N = 57) individuals had orthopedic injuries who were not wearing helmets.

Conclusion:

Under the limitations of the study, we conclude that majority of the two-wheelers are not wearing helmets. This study has demonstrated that the impact of wearing helmet on occurrence of craniofacial and orthopedic injuries is less.

Cellular organization and boundary formation in craniofacial development

Craniofacial morphogenesis is a highly dynamic process that requires changes in the behaviors and physical properties of cells in order to achieve the proper organization of different craniofacial structures. Boundary formation is a critical process in cellular organization, patterning, and ultimately tissue separation. There are several recurring cellular mechanisms through which boundary formation and cellular organization occur including, transcriptional patterning, cell segregation, cell adhesion and migratory guidance. Disruption of normal boundary formation has dramatic morphological consequences, and can result in human craniofacial congenital anomalies. In this review we discuss boundary formation during craniofacial development, specifically focusing on the cellular behaviors and mechanisms underlying the self-organizing properties that are critical for craniofacial morphogenesis.

Oro-dental and cranio-facial characteristics of osteogenesis imperfecta type V

Osteogenesis imperfecta (OI) type V is an ultrarare heritable bone disorder caused by the heterozygous c.-14C > T mutation in IFITM5. The oro-dental and craniofacial phenotype has not been described in detail, which we therefore undertook to evaluate in a multicenter study (Brittle Bone Disease Consortium). Fourteen individuals with OI type V (age 3-50 years; 10 females, 4 males) underwent dental and craniofacial assessment. None of the individuals had dentinogenesis imperfecta. Six of the 9 study participants (66%) for whom panoramic radiographs were obtained had at least one missing tooth (range 1-9). Class II molar occlusion was present in 8 (57%) of the 14 study participants. The facial profile was retrusive and lower face height was decreased in 8 (57%) individuals. Cephalometry, performed in three study participants, revealed a severely retrusive maxilla and mandible, and moderately to severly retroclined incisors in a 14-year old girl, a protrusive maxilla and a retrusive mandible in a 14-year old boy. Cone beam computed tomograpy scans were obtained from two study participants and demonstrated intervertebral disc calcification at the C2-C3 level in one individual. Our study observed that OI type V is associated with missing permanent teeth, especially permanent premolar, but not with dentinogenesis imperfecta. The pattern of craniofacial abnormalities in OI type V thus differs from that in other severe OI types, such as OI type III and IV, and could be described as a bimaxillary retrusive malocclusion with reduced lower face height and multiple missing teeth.

Advancements in craniofacial prosthesis fabrication: A narrative review of holistic treatment

The treatment of craniofacial anomalies has been challenging as a result of technological shortcomings that could not provide a consistent protocol to perfectly restore patient-specific anatomy. In the past, wax-up and impression-based maneuvers were implemented to achieve this clinical end. However, with the advent of computer-aided design and computer-aided manufacturing (CAD/CAM) technology, a rapid and cost-effective workflow in prosthetic rehabilitation has taken the place of the outdated procedures. Because the use of implants is so profound in different facets of restorative dentistry, their placement for craniofacial prosthesis retention has also been widely popular and advantageous in a variety of clinical settings. This review aims to effectively describe the well-rounded and interdisciplinary practice of craniofacial prosthesis fabrication and retention by outlining fabrication, osseointegrated implant placement for prosthesis retention, a myriad of clinical examples in the craniofacial complex, and a glimpse of the future of bioengineering principles to restore bioactivity and physiology to the previously defected tissue.