A population-based study of craniosynostosis in metropolitan Atlanta, 1989-2003

Cranial bone microarchitecture in a mouse model for syndromic craniosynostosis

Crouzon syndrome is a congenital craniofacial disorder caused by mutations in the Fibroblast Growth Factor Receptor 2 (FGFR2). It is characterized by the premature fusion of cranial sutures, leading to a brachycephalic head shape, and midfacial hypoplasia. The aim of this study was to investigate the effect of the FGFR2 mutation on the microarchitecture of cranial bones at different stages of postnatal skull development, using the FGFR2C342Y mouse model. Apart from craniosynostosis, this model shows cranial bone abnormalities. High-resolution synchrotron microtomography images of the frontal and parietal bone were acquired for both FGFR2C342Y/+ (Crouzon, heterozygous mutant) and FGFR2+/+ (control, wild-type) mice at five ages (postnatal days 1, 3, 7, 14 and 21, n = 6 each). Morphometric measurements were determined for cortical bone porosity: osteocyte lacunae and canals. General linear model to assess the effect of age, anatomical location and genotype was carried out for each morphometric measurement. Histological analysis was performed to validate the findings. In both groups (Crouzon and wild-type), statistical difference in bone volume fraction, average canal volume, lacunar number density, lacunar volume density and canal volume density was found at most age points, with the frontal bone generally showing higher porosity and fewer lacunae. Frontal bone showed differences between the Crouzon and wild-type groups in terms of lacunar morphometry (average lacunar volume, lacunar number density and lacunar volume density) with larger, less dense lacunae around the postnatal age of P7-P14. Histological analysis of bone showed marked differences in frontal bone only. These findings provide a better understanding of the pathogenesis of Crouzon syndrome and will contribute to computational models that predict postoperative changes with the aim to improve surgical outcome.

Mystery of the Muenke midface: spheno-occipital synchondrosis fusion and craniofacial skeletal patterns

PURPOSE

The spheno-occipital synchondrosis (SOS) is an important site of endochondral ossification in the cranial base that closes prematurely in Apert, Crouzon, and Pfeiffer syndromes, which contributes to varying degrees of midface hypoplasia. The facial dysmorphology of Muenke syndrome, in contrast, is less severe with low rates of midface hypoplasia. We thus evaluated the timing of SOS fusion and cephalometric landmarks in patients with Muenke syndrome compared to normal controls.

METHODS

Patients with Muenke syndrome who had at least one fine-cut head computed tomography scan performed from 2000 to 2020 were retrospectively reviewed. A case-control study was performed of patient scans and age- and sex-matched control scans. SOS fusion status was evaluated as open, partially closed, or closed.

RESULTS

We included 28 patients and compared 77 patient scans with 77 control scans. Kaplan-Meier analysis demonstrated an insignificantly earlier timeline of SOS fusion in Muenke syndrome (p = 0.300). Mean sella-orbitale (SO) distance was shorter (44.0 ± 6.6 vs. 47.7 ± 6.7 mm, p < 0.001) and mean sella-nasion-Frankfort horizontal (SN-FH) angle was greater (12.1° ± 3.8° vs. 10.1° ± 3.2°, p < 0.001) in the Muenke group, whereas mean sella-nasion-A point (SNA) angle was similar and normal (81.1° ± 5.7° vs. 81.4° ± 4.7°, p = 0.762).

CONCLUSION

Muenke syndrome is characterized by mild and often absent midfacial hypoplasia, with the exception of slight retropositioning of the infraorbital rim. Interestingly, SOS fusion patterns in these patients are not significantly different from age- and sex-matched controls despite an increased odds of fusion. It is possible that differences in timing of SOS fusion may manifest phenotypically at the infraorbital rim rather than at the maxilla.

Sociodemographic Disparities and Postoperative Outcomes Following Cranial Vault Remodeling for Craniosynostosis: Analysis of the 2012 to 2021 NSQIP-Pediatric Database

OBJECTIVE

The objective of this study was to assess whether race and ethnicity are independent predictors of inferior postoperative clinical outcomes, including increased complication rates, extended length of stay (LOS), and unplanned 30-day readmission following cranial vault repair for craniosynostosis.

METHODS

A retrospective cohort study was performed using the American College of Surgeons National Surgical Quality Improvement Program-Pediatric database. Pediatric patients under 2 years of age undergoing cranial vault repair for craniosynostosis between 2012 and 2021 were identified using the International Classification of Diseases-9/10 and Current Procedural Terminology codes. Patients were dichotomized into 4 cohorts: non-Hispanic White (NHW), non-Hispanic Black (NHB), Hispanic, and other. Only patients with available race and ethnicity data were included in this study. Patient demographics, comorbidities, surgical variables, postoperative adverse events, and hospital resource utilization were assessed. Multivariate logistic regression analysis was used to assess the impact of race on complications, extended LOS, and unplanned readmissions.

RESULTS

In our cohort of 7764 patients, 72.80% were NHW, 8.44% were NHB, 15.10% were Hispanic, and 3.67% were categorized as "other." Age was significantly different between the 4 cohorts ( P <0.001); NHB patients were the oldest, with an average age of 327.69±174.57 days old. Non-Hispanic White experienced the least adverse events while NHB experienced the most ( P =0.01). Total operative time and hospital LOS were shorter for NHW patients ( P <0.001 and P <0.001, respectively). Rates of unplanned 30-day readmission, unplanned reoperation, and 30-day mortality did not differ significantly between the 4 cohorts. On multivariate analysis, race was found to be an independent predictor of extended LOS [NHB: adjusted odds ratio: 1.30 (1.04-1.62), P=0.021; other: 2.28 (1.69-3.04), P =0.005], but not of complications or readmission.

CONCLUSIONS

Our study demonstrates that racial and ethnic disparities exist among patients undergoing cranial vault reconstruction for craniosynostosis. These disparities, in part, may be due to delayed age of presentation among non-Hispanic, non-White patients. Further investigations to elucidate the underlying causes of these disparities are necessary to address gaps in access to care and provide equitable health care to at-risk populations.

Nonsyndromic Craniosynostosis Correlation Between Ethnicity, Race, and Pattern of Affected Suture Type: Meta-Analysis

BACKGROUND

Previous studies have sought to analyze risk factors associated with craniosynostosis and while syndromic craniosynostosis is often linked to genetic mutations, the factors impacting nonsyndromic cases are less investigated. The aim of current meta-analysis is to evaluate the relationship between ethnicity and suture type in nonsyndromic craniosynostosis patients.

METHODS

The search term "craniosynostosis [Title/Abstract] AND (race [Title/Abstract] OR ethnicity [Title/Abstract])) NOT (syndrome [Title/Abstract])" was used to search the PubMed, Cochrane, and MEDLINE databases. Analyses were conducted separately for each racial and ethnic group for each suture type cohort. Odds ratios were conducted for each suture cohort and confounders were adjusted using linear mixed-effect models. Because of the homogeneity of the populations and categorical nature of the classification, binary logistic regression was run on aggregate data.

RESULTS

The literature search yielded 165 articles. After reviewing titles, abstracts, and manuscript contents of these articles, 5 studies were ultimately included in a meta-analysis. Studies with missing data for a particular cohort or variable were excluded from the respective analysis. Hispanic children had higher odds of sagittal suture involvement (OR: 1.53, P <0.001), whereas Asian had coronal suture (OR: 2.47, P <0.001). Both Asian and African American children had significantly lower odds of sagittal suture involvement (OR: 0.50, P <0.001 and OR: 0.7, P =0.04, respectively).

CONCLUSION

The relationship between ethnicity and craniosynostosis has been suggested as a risk factor, but without definitive conclusion. Present meta-analysis findings demonstrated association between ethnicity and suture type, however further research with larger scale and geographically varied data is warranted.

Epidemiologic Assessment of Craniosynostosis in Mississippi's Pediatric Population from 2015 to 2020

OBJECTIVES

This study aimed to report geographic and demographic patterns of patients with craniosynostosis (CS) treated at Children's of Mississippi, the state's only American Cleft Palate-Craniofacial Association-approved craniofacial team.

METHODS

Patients with CS were treated at a tertiary pediatric hospital cared for by craniofacial surgeons and neurosurgeons from 2015 to 2020. Demographic, geographic, and CS diagnosis details, including sex, gestational age, race, ethnicity, insurance status, and affected cranial suture type(s), number, and associated syndromic diagnosis were collected, including birth county and total live births from state data. Significant differences between prevalence of CS in four regions of Mississippi were examined using two-tailed t tests (P < 0.05).

RESULTS

Among 222,819 live births in Mississippi between 2015 and 2020, 79 pediatric patients presented to Children's of Mississippi with CS, with an overall incidence of 0.355/1000 live births. Most cases were nonsyndromic CS (82%, n = 65) affecting a single major cranial suture (81%, n = 64). The overall incidence of CS was higher in the coastal and central regions compared with northeast Mississippi, at 0.333 and 0.527 vs 0.132/1000 live births (P = 0.012 and P = 0.004), respectively.

CONCLUSIONS

Results from this study suggest regional patterns of CS in Mississippi, which may reflect actual incidence patterns or proximity to Children's of Mississippi. Further study could reveal regional differences in risk factors underlying CS incidence or access to specialized CS care for different regions in the state. This will lead to opportunities for institutional outreach to decrease the burden of CS care in Mississippi.

The Top 100 Most-Cited Publications in Clinical Craniofacial Research

INTRODUCTION

Craniosynostosis is a birth defect defined as premature closure of sutures leading to possible neurological deficits and cosmetic deformities. Most of the current literature to date focuses on craniosynostosis etiology by analyzing genetics. This paper is a bibliometric analysis of the most influential works related to the clinical management of craniosynostosis to help guide clinicians in their decision-making.

METHODS AND MATERIALS

Clarivate Web of Science database was used to identify the top 100 most-cited articles addressing the clinical management of craniosynostosis. A bibliometric review was performed to analyze publication metrics and track research trends.

RESULTS

The 100 most-cited publications pertaining to craniosynostosis management were cited a cumulative 12,779 times. The highest cited article was Shillito and colleagues' "Craniosynostosis: A Review Of 519 Surgical Patients" with 352 citations. The oldest clinical craniosynostosis article dates back to 1948, and the most recent was published in 2016. The year with the most clinical-focused publications was 2011. The most prolific author was Renier, D. The United States produced 56 of the 100 articles. Most articles (n=52) were level 3 evidence.

DISCUSSION

This bibliometric evaluation of craniosynostosis provides insight into the most impactful literature on this topic. The highest cited articles retrospectively analyze large sample sizes, outline proper evaluation, discuss intervention timelines, and highlight specific treatment plans for this birth defect. By filtering through existing literature, this analysis can guide clinicians on the management of craniosynostosis to maximize patient outcomes.

Deamidation enables pathogenic SMAD6 variants to activate the BMP signaling pathway

The BMP signaling pathway plays a crucial role in regulating early embryonic development and tissue homeostasis. SMAD6 encodes a negative regulator of BMP, and rare variants of SMAD6 are recurrently found in individuals with birth defects. However, we observed that a subset of rare pathogenic variants of SMAD6 consistently exhibited positive regulatory effects instead of the initial negative effects on the BMP signaling pathway. We sought to determine whether these SMAD6 variants have common pathogenic mechanisms. Here, we showed that pathogenic SMAD6 variants accompanying this functional reversal exhibit similar increases in deamidation. Mechanistically, increased deamidation of SMAD6 variants promotes the accumulation of the BMP receptor BMPR1A and the formation of new complexes, both of which lead to BMP signaling pathway activation. Specifically, two residues, N262 and N404, in SMAD6 were identified as the crucial sites of deamidation, which was catalyzed primarily by glutamine-fructose-6-phosphate transaminase 2 (GFPT2). Additionally, treatment of cells harboring SMAD6 variants with a deamidase inhibitor restored the inhibitory effect of SMAD6 on the BMP signaling pathway. Conversely, when wild-type SMAD6 was manually simulated to mimic the deamidated state, the reversed function of activating BMP signaling was reproduced. Taken together, these findings show that deamidation of SMAD6 plays a crucial role in the functional reversal of BMP signaling activity, which can be induced by a subset of various SMAD6 variants. Our study reveals a common pathogenic mechanism shared by these variants and provides a potential strategy for preventing birth defects through deamidation regulation, which might prevent the off-target effects of gene editing.

Whole genome sequencing identifies associations for nonsyndromic sagittal craniosynostosis with the intergenic region of BMP2 and noncoding RNA gene LINC01428

Craniosynostosis (CS) is a major birth defect resulting from premature fusion of cranial sutures. Nonsyndromic CS occurs more frequently than syndromic CS, with sagittal nonsyndromic craniosynostosis (sNCS) presenting as the most common CS phenotype. Previous genome-wide association and targeted sequencing analyses of sNCS have identified multiple associated loci, with the strongest association on chromosome 20. Herein, we report the first whole-genome sequencing study of sNCS using 63 proband-parent trios. Sequencing data for these trios were analyzed using the transmission disequilibrium test (TDT) and rare variant TDT (rvTDT) to identify high-risk rare gene variants. Sequencing data were also examined for copy number variants (CNVs) and de novo variants. TDT analysis identified a highly significant locus at 20p12.3, localized to the intergenic region between BMP2 and the noncoding RNA gene LINC01428. Three variants (rs6054763, rs6054764, rs932517) were identified as potential causal variants due to their probability of being transcription factor binding sites, deleterious combined annotation dependent depletion scores, and high minor allele enrichment in probands. Morphometric analysis of cranial vault shape in an unaffected cohort validated the effect of these three single nucleotide variants (SNVs) on dolichocephaly. No genome-wide significant rare variants, de novo loci, or CNVs were identified. Future efforts to identify risk variants for sNCS should include sequencing of larger and more diverse population samples and increased omics analyses, such as RNA-seq and ATAC-seq.

A Case of Trigeminal Neuralgia in an Adult Patient With Lambdoid Synostosis

Trigeminal neuralgia (TN) is characterized by sudden, brief intense pain in the distribution of the unilateral trigeminal nerve (TGN). Neurovascular compression (NVC) of the TGN is the most common cause of TN. Recent studies have suggested that a structural anomaly of the posterior cranial fossa might be involved in the development of TN, and several studies have documented the association between NVC-related TN and congenital posterior cranial deformities in adults. We present the case of a 56-year-old woman with NVC-related TN and unilateral lambdoid synostosis (ULS), along with a literature review, to investigate the relationship between TN and structural anomalies of the posterior fossa. This is the first report of TN in an adult with ULS. Mild and asymptomatic cases of lambdoid synostosis might have a higher incidence of NVC-related TN in association with posterior cranial fossa deformities.

Transforming growth factor beta signaling and craniofacial development: modeling human diseases in zebrafish

Humans and other jawed vertebrates rely heavily on their craniofacial skeleton for eating, breathing, and communicating. As such, it is vital that the elements of the craniofacial skeleton develop properly during embryogenesis to ensure a high quality of life and evolutionary fitness. Indeed, craniofacial abnormalities, including cleft palate and craniosynostosis, represent some of the most common congenital abnormalities in newborns. Like many other organ systems, the development of the craniofacial skeleton is complex, relying on specification and migration of the neural crest, patterning of the pharyngeal arches, and morphogenesis of each skeletal element into its final form. These processes must be carefully coordinated and integrated. One way this is achieved is through the spatial and temporal deployment of cell signaling pathways. Recent studies conducted using the zebrafish model underscore the importance of the Transforming Growth Factor Beta (TGF-β) and Bone Morphogenetic Protein (BMP) pathways in craniofacial development. Although both pathways contain similar components, each pathway results in unique outcomes on a cellular level. In this review, we will cover studies conducted using zebrafish that show the necessity of these pathways in each stage of craniofacial development, starting with the induction of the neural crest, and ending with the morphogenesis of craniofacial elements. We will also cover human skeletal and craniofacial diseases and malformations caused by mutations in the components of these pathways (e.g., cleft palate, craniosynostosis, etc.) and the potential utility of zebrafish in studying the etiology of these diseases. We will also briefly cover the utility of the zebrafish model in joint development and biology and discuss the role of TGF-β/BMP signaling in these processes and the diseases that result from aberrancies in these pathways, including osteoarthritis and multiple synostoses syndrome. Overall, this review will demonstrate the critical roles of TGF-β/BMP signaling in craniofacial development and show the utility of the zebrafish model in development and disease.

Prenatal and infantile diagnosis of craniosynostosis in individuals with RASopathies

Fetuses with RASopathies can have a wide variety of anomalies including increased nuchal translucency, hydrops fetalis, and structural anomalies (typically cardiac and renal). There are few reports that describe prenatal-onset craniosynostosis in association with a RASopathy diagnosis. We present clinical and molecular characteristics of five individuals with RASopathy and craniosynostosis. Two were diagnosed with craniosynostosis prenatally, 1 was diagnosed as a neonate, and 2 had evidence of craniosynostosis noted as neonates without formal diagnosis until later. Two of these individuals have Noonan syndrome (PTPN11 and KRAS variants) and three individuals have Cardiofaciocutaneous syndrome (KRAS variants). Three individuals had single suture synostosis and two had multiple suture involvement. The most common sutures involved were sagittal (n = 3), followed by coronal (n = 3), and lambdoid (n = 2) sutures. This case series confirms craniosynostosis as one of the prenatal findings in individuals with RASopathies and emphasizes the importance of considering a RASopathy diagnosis in fetuses with multiple anomalies in combination with craniosynostosis.

Craniosynostosis in molecularly diagnosed Kabuki syndrome: Prevalence and clinical implications

Kabuki syndrome (KS) is characterized by growth impairment, psychomotor delay, congenital heart disease, and distinctive facial features. KMT2D and KDM6A have been identified as the causative genes of KS. Craniosynostosis (CS) has been reported in individuals with KS; however, its prevalence and clinical implications remain unclear. In this retrospective study, we investigated the occurrence of CS in individuals with genetically diagnosed KS and examined its clinical significance. Among 42 individuals with genetically diagnosed KS, 21 (50%) exhibited CS, with 10 individuals requiring cranioplasty. No significant differences were observed based on sex, causative gene, and molecular consequence among individuals with KS who exhibited CS. Both individuals who underwent evaluation with three-dimensional computed tomography (3DCT) and those who required surgery tended to exhibit cranial dysmorphology. Notably, in several individuals, CS was diagnosed before KS, suggesting that CS could be one of the clinical features by which clinicians can diagnose KS. This study highlights that CS is one of the noteworthy complications in KS, emphasizing the importance of monitoring cranial deformities in the health management of individuals with KS. The findings suggest that in individuals where CS is a concern, conducting 3DCT evaluations for CS and digital impressions are crucial.

Prevalence of craniosynostosis in Finland, 1987-2010: A population-based study

BACKGROUND

Craniosynostosis is a prevalent craniofacial malformation in Finland; however, comprehensive population-based epidemiological data are limited. This study aimed to estimate the total and birth prevalence of craniosynostosis in Finland from 1987 to 2010 and examine temporal trends.

METHODS

We collected the data from nationwide registers maintained by the Finnish Institute for Health and Welfare and Statistics Finland, as well as treating hospitals, encompassing live births, stillbirths, terminations for fetal anomalies, and infant deaths with suspected or diagnosed craniosynostosis or skull deformation. A craniofacial surgeon and a clinical geneticist reviewed 1878 medical records for diagnostic confirmation.

RESULTS

Out of 877 craniosynostosis cases, 83% were single-suture synostoses (all live births), 10% craniosynostosis syndromes, and 7% multisutural non-syndromic synostoses. Live birth prevalence from 1987 to 2010 was 6.0/10,000 live births, ranging from 5.0/10,000 in 1987 to 7.5/10,000 in 2010. Total prevalence, including live births, stillbirths, and terminations, varied from 5.0/10,000 in 1987 to 8.0/10,000 in 2010. Sagittal synostosis was the most common synostosis, with a prevalence of 3.9/10,000 live births, followed by metopic (0.6/10,000), unicoronal (0.4/10,000), and unilambdoid (0.1/10,000) synostoses.

CONCLUSIONS

The total combined prevalence of all craniosynostosis types significantly increased driven by a nonsignificant rise across all subgroups and a significant increase in the syndrome group. In live births increase was significant only within the syndrome subgroup, primarily due to an increase in Muenke syndrome patients. The rising prevalence of syndromes necessitates further investigation. Contrasting with trends in Europe, Australia, and the USA, Finland showed no significant increase in metopic craniosynostosis.

Optic neuropathy in craniosynostosis

Craniosynostosis (CS) or the premature fusion of one or more cranial sutures in utero, or during the first years of life, can present in isolation or as a multisystem clinical disorder with a particular impact on visual function. Among ophthalmic complications, optic neuropathy is a significant cause of irreversible vision loss in these patients. Children with CS are at higher risk of developing elevated intracranial pressure which can lead to papilledema and, ultimately, optic atrophy. In addition, sometimes associated obstructive sleep apnea, abnormalities in central nervous system venous development, and Chiari malformation may contribute to optic neuropathy. Ophthalmologists have an important role in managing a number of coexistent ophthalmologic complications such as strabismus, anisometropia, amblyopia, ptosis, and exposure keratopathy in addition to maintaining surveillance for early signs of optic neuropathy; they play a critical consultative role contributing to the decision for primary or repeat decompressive surgery. In this article, we aim to review the etiology, diagnostic approach, and management of optic neuropathies in patients with craniosynostosis.

Frequency and predictors of concurrent complications in multi-suture release for syndromic craniosynostosis

PURPOSE

Understanding the complication profile of craniosynostosis surgery is important, yet little is known about complication co-occurrence in syndromic children after multi-suture craniosynostosis surgery. We examined concurrent perioperative complications and predictive factors in this population.

METHODS

In this retrospective cohort study, children with syndromic diagnoses and multi-suture involvement who underwent craniosynostosis surgery in 2012-2020 were identified from the National Surgical Quality Improvement Program-Pediatric database. The primary outcome was concurrent complications; factors associated with concurrent complications were identified. Correlations between complications and patient outcomes were assessed.

RESULTS

Among 5,848 children identified, 161 children (2.75%) had concurrent complications: 129 (2.21%) experienced two complications and 32 (0.55%) experienced ≥ 3. The most frequent complication was bleeding/transfusion (69.53%). The most common concurrent complications were transfusion/superficial infection (27.95%) and transfusion/deep incisional infection (13.04%) or transfusion/sepsis (13.04%). Two cardiac factors (major cardiac risk factors (odds ratio (OR) 3.50 [1.92-6.38]) and previous cardiac surgery (OR 4.87 [2.36-10.04])), two pulmonary factors (preoperative ventilator dependence (OR 3.27 [1.16-9.21]) and structural pulmonary/airway abnormalities (OR 2.89 [2.05-4.08])), and preoperative nutritional support (OR 4.05 [2.34-7.01]) were independently associated with concurrent complications. Children who received blood transfusion had higher odds of deep surgical site infection (OR 4.62 [1.08-19.73]; p = 0.04).

CONCLUSIONS

Our results indicate that several cardiac and pulmonary risk factors, along with preoperative nutritional support, were independently associated with concurrent complications but procedural factors were not. This information can help inform presurgical counseling and preoperative risk stratification in this population.

Impact of data synthesis strategies for the classification of craniosynostosis

Introduction

Photogrammetric surface scans provide a radiation-free option to assess and classify craniosynostosis. Due to the low prevalence of craniosynostosis and high patient restrictions, clinical data are rare. Synthetic data could support or even replace clinical data for the classification of craniosynostosis, but this has never been studied systematically.

Methods

We tested the combinations of three different synthetic data sources: a statistical shape model (SSM), a generative adversarial network (GAN), and image-based principal component analysis for a convolutional neural network (CNN)-based classification of craniosynostosis. The CNN is trained only on synthetic data but is validated and tested on clinical data.

Results

The combination of an SSM and a GAN achieved an accuracy of 0.960 and an F1 score of 0.928 on the unseen test set. The difference to training on clinical data was smaller than 0.01. Including a second image modality improved classification performance for all data sources.

Conclusions

Without a single clinical training sample, a CNN was able to classify head deformities with similar accuracy as if it was trained on clinical data. Using multiple data sources was key for a good classification based on synthetic data alone. Synthetic data might play an important future role in the assessment of craniosynostosis.

The Outcomes of Endoscopic Suturectomy in Syndromic Craniosynostosis

OBJECTIVE

Endoscopic suturectomy is a widely practiced surgical option for infants with craniosynostosis. But the efficacy and safety of the procedure remain unclear in syndromic patients. This study aims to evaluate the efficacy and safety of endoscopic suturectomy for patients with syndromic craniosynostosis.

METHODS

From January 2013 to December 2020, 242 patients underwent endoscopic suturectomy at our institution. The surgical outcome was determined to be favorable or unfavorable based upon the necessity of an additional cranial surgery upon the last follow-up. First, we analyzed the outcomes of 26 syndromic craniosynostosis patients who have followed up for over a year. Second, we compared the outcomes between the syndromic (N=12) and nonsyndromic (N=11) patients with bilateral coronal synostosis who have followed up for over a year.

RESULTS

Twenty-three out of 26 syndromic craniosynostosis patients (88%) showed favorable outcomes without significant complications. In the analysis for bilateral coronal synostosis patients, 11 of 12 syndromic patients (92%) presented favorable outcomes, and all nonsyndromic patients showed favorable outcomes. No significant differences were observed in various anthropometric indices (cranial index, intracranial volume, anterior cranial height, anterior cranial base length, and cranial height-length index) and surgical outcomes between syndromic and nonsyndromic groups.

CONCLUSIONS

Endoscopic suturectomy has the potential to be a surgical option for syndromic craniosynostosis. Even for patients with unfavorable outcomes, endoscopic suturectomy could serve as a bridge treatment for infants to counter cranial deformation before additional extensive surgery.

3D-2D Distance Maps Conversion Enhances Classification of Craniosynostosis

OBJECTIVE

Diagnosis of craniosynostosis using photogrammetric 3D surface scans is a promising radiation-free alternative to traditional computed tomography. We propose a 3D surface scan to 2D distance map conversion enabling the usage of the first convolutional neural networks (CNNs)-based classification of craniosynostosis. Benefits of using 2D images include preserving patient anonymity, enabling data augmentation during training, and a strong under-sampling of the 3D surface with good classification performance.

METHODS

The proposed distance maps sample 2D images from 3D surface scans using a coordinate transformation, ray casting, and distance extraction. We introduce a CNN-based classification pipeline and compare our classifier to alternative approaches on a dataset of 496 patients. We investigate into low-resolution sampling, data augmentation, and attribution mapping.

RESULTS

Resnet18 outperformed alternative classifiers on our dataset with an F1-score of 0.964 and an accuracy of 98.4%. Data augmentation on 2D distance maps increased performance for all classifiers. Under-sampling allowed 256-fold computation reduction during ray casting while retaining an F1-score of 0.92. Attribution maps showed high amplitudes on the frontal head.

CONCLUSION

We demonstrated a versatile mapping approach to extract a 2D distance map from the 3D head geometry increasing classification performance, enabling data augmentation during training on 2D distance maps, and the usage of CNNs. We found that low-resolution images were sufficient for a good classification performance.

SIGNIFICANCE

Photogrammetric surface scans are a suitable craniosynostosis diagnosis tool for clinical practice. Domain transfer to computed tomography seems likely and can further contribute to reducing ionizing radiation exposure for infants.

Ultra-low-dose computed tomography with deep learning reconstruction for craniosynostosis at radiation doses comparable to skull radiographs: a pilot study

BACKGROUND

Craniofacial computed tomography (CT) is the diagnostic investigation of choice for craniosynostosis, but high radiation dose remains a concern.

OBJECTIVE

To evaluate the image quality and diagnostic performance of an ultra-low-dose craniofacial CT protocol with deep learning reconstruction for diagnosis of craniosynostosis.

MATERIALS AND METHODS

All children who underwent initial craniofacial CT for suspected craniosynostosis between September 2021 and September 2022 were included in the study. The ultra-low-dose craniofacial CT protocol using 70 kVp, model-based iterative reconstruction and deep learning reconstruction techniques was compared with a routine-dose craniofacial CT protocol. Quantitative analysis of the signal-to-noise ratio and noise was performed. The 3-dimensional (D) volume-rendered images were independently evaluated by two radiologists with regard to surface coarseness, step-off artifacts and overall image quality on a 5-point scale. Sutural patency was assessed for each of six sutures. Radiation dose was compared between the two protocols.

RESULTS

Among 29 patients (15 routine-dose CT and 14 ultra-low-dose CT), 23 patients had craniosynostosis. The 3-D volume-rendered images of ultra-low-dose CT without deep learning showed decreased image quality compared to routine-dose CT. The 3-D volume-rendered images of ultra-low-dose CT with deep learning reconstruction showed higher noise level, higher surface coarseness but decreased step-off artifacts, comparable signal-to-noise ratio and overall similar image quality compared to the routine-dose CT images. Diagnostic performance for detecting craniosynostosis at the suture level showed no significant difference between ultra-low-dose CT without deep learning reconstruction, ultra-low-dose CT with deep learning reconstruction and routine-dose CT. The estimated effective radiation dose for the ultra-low-dose CT was 0.05 mSv (range, 0.03-0.06 mSv), a 95% reduction in dose over the routine-dose CT at 1.15 mSv (range, 0.54-1.74 mSv). This radiation dose is comparable to 4-view skull radiography (0.05-0.1 mSv) and lower than previously reported effective dose for craniosynostosis protocols (0.08-3.36 mSv).

CONCLUSION

In this pilot study, an ultra-low-dose CT protocol using radiation doses at a level similar to skull radiographs showed preserved diagnostic performance for craniosynostosis, but decreased image quality compared to the routine-dose CT protocol. However, by combining the ultra-low-dose CT protocol with deep learning reconstruction, image quality was improved to a level comparable to the routine-dose CT protocol, without sacrificing diagnostic performance for craniosynostosis.

Ophthalmic Manifestations of Unilateral Coronal Synostosis

PURPOSE

To summarize the ophthalmic manifestations of unilateral coronal synostosis patients.

METHODS

We performed a literature search in the electronic database of PubMed, CENTRAL, Cochrane, and Ovid Medline guided by Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement for studies evaluating ophthalmic manifestations of unilateral coronal synostosis.

RESULTS

Unilateral coronal synostosis, also called unicoronal synostosis, may be mistaken for deformational plagiocephaly, an asymmetric skull flattening common in newborns. Characteristic facial features, however, distinguish the two. Ophthalmic manifestations of unilateral coronal synostosis include a "harlequin deformity", anisometropic astigmatism, strabismus, amblyopia, and significant orbital asymmetry. The astigmatism is greater on the side opposite the fused coronal suture. Optic neuropathy is uncommon unless unilateral coronal synostosis accompanies more complex multi-suture craniosynostosis. In many cases, surgical intervention is recommended; without intervention, skull asymmetry and ophthalmic disorders tend to worsen with time. Unilateral coronal synostosis can be managed by early endoscopic stripping of the fused suture and helmeting through a year of age or by fronto-orbital-advancement at approximately 1 year of age. Several studies have demonstrated that anisometropic astigmatism, amblyopia, and severity of strabismus are significantly lower after earlier intervention with endoscopic strip craniectomy and helmeting compared to treatment by fronto-orbital-advancement. It remains unknown whether the earlier timing or the nature of the procedure is responsible for the improved outcomes. As endoscopic strip craniectomy can only be performed in the first few months of life, early recognition of the facial, orbital, eyelid, and ophthalmic characteristics by consultant ophthalmologists enables expeditious referral and optimized ophthalmic outcomes.

CONCLUSION

Timely identification of craniofacial and ophthalmic manifestations of infants with unilateral coronal synostosis is important. Early recognition and prompt endoscopic treatment appears to optimize ocular outcomes.

Genetic diagnostic yield in an 11-year cohort of craniosynostosis patients

Craniosynostosis may present in isolation, 'non-syndromic', or with additional congenital anomalies/neurodevelopmental disorders, 'syndromic'. Clinical focus shifted from confirming classical syndromic cases to offering genetic testing to all craniosynostosis patients. This retrospective study assesses diagnostic yield of molecular testing by investigating prevalences of chromosomal and monogenic (likely) pathogenic variants in an 11-year cohort of 1020 craniosynostosis patients. 502 children underwent genetic testing. Pathogenic variants were identified in 174 patients (35%). Diagnostic yield was significantly higher in syndromic craniosynostosis (62%) than in non-syndromic craniosynostosis (6%). Before whole exome sequencing (WES) emerged, single-gene testing was performed using Sanger sequencing or multiplex ligation-dependent probe amplification (MLPA). Diagnostic yield was 11% and was highest for EFNB1, FGFR2, FGFR3, and IL11RA. Diagnostic yield for copy number variant analysis using microarray was 8%. From 2015 onwards, the WES craniosynostosis panel was implemented, with a yield of 10%. In unsolved, mainly syndromic, cases suspected of a genetic cause, additional WES panels (multiple congenital anomalies (MCA)/intellectual disability (ID)) or open exome analysis were performed with an 18% diagnostic yield. To conclude, microarray and the WES craniosynostosis panel are key to identifying pathogenic variants. in craniosynostosis patients. Given the advances in genetic diagnostics, we should look beyond the scope of the WES craniosynostosis panel and consider extensive genetic diagnostics (e.g. open exome sequencing, whole genome sequencing, RNA sequencing and episignature analysis) if no diagnosis is obtained through microarray and/or WES craniosynostosis panel. If parents are uncomfortable with more extensive diagnostics, MCA or ID panels may be considered.

Torticollis in Non-Syndromic Unicoronal Craniosynostosis Is Predominantly Ocular Related

(1) Background: Patients with unicoronal craniosynostosis (UCS) often show torticollis which can result from either an ocular cause or contraction of the sternocleidomastoid muscle. For clinicians, it is crucial to know the prevalence of ocular torticollis (OT) to ensure appropriate referral for treatment. Furthermore, associated ophthalmic features with OT in these patients are scarcely described. The aim of this study was to determine the prevalence of OT in non-syndromic UCS patients and investigate its associated ophthalmic features. (2) Methods: In this descriptive cross-sectional study medical records of non-syndromic UCS patients treated between 1994-2022 in one tertiary care hospital in The Netherlands were retrospectively reviewed. Collected data included: diagnosis and type of torticollis, binocular single vision (BSV), strabismus, ocular motility, alphabetical patterns, refractive error, and amblyopia. Patients were classified as OT, based on their ophthalmic and/or orthoptic diagnosis. Prevalence was determined with the 95% CI using the Clopper-Pearson exact test. Associations between OT and the ophthalmic features were determined using Chi-square or Fishers' exact test and its effect size was calculated using Cramer's V. (3) Results: In total, 146 patients were included, of whom 57 had torticollis. An ocular cause for the torticollis was found in 54 patients. The prevalence of OT was 37% (n = 146; 95% CI [0.292-0.454]). Significant associations were found between OT and strabismus (p < 0.001), ocular motility abnormalities (p < 0.001), alphabetical patterns (p < 0.001), and amblyopia (p = 0.002). BSV (p = 0.277) and refractive error (p = 1.0) were not significantly associated with OT. However, in OT the BSV was relatively poor (42.1%) and more frequently absent (26.3%) compared to the non-torticollis group (7% poor and 16.3% absent). In both groups, excyclotorsion was predominantly present (62.3%). (4) Conclusions: In 95% of cases, torticollis in UCS patients is ocular-related. Overall, one in three patients with UCS have OT. This study emphasizes the importance of a timely referral of all patients with UCS with torticollis to an orthoptist and/or ophthalmologist, specialized in diagnosing and treatment of OT, before considering physiotherapy.

A Novel Phenotype of Calvarial Thickening and Increased Rates of Premature Calvarial Suture Closure in Children With Chronic Lung Disease

PURPOSE

The purpose of this study was to characterize a novel type of calvarial thickening and provide objective measurements of skull thickness and calvarial suture morphology in patients with bronchopulmonary dysplasia.

METHODS

Infants with severe bronchopulmonary dysplasia who also had undergone computed tomography (CT) scans were identified from the neonatal chronic lung disease program database. Thickness analysis was performed using Materialise Mimics.

RESULTS

The chronic lung disease team treated 319 patients during the study interval of which, 58 patients (18.2%) had head CT available. Twenty-eight (48.3%) were found to have calvarial thickening. The rate of premature suture closure in the study population was 36.2% (21 of 58 patients), with 50.0% of affected cohort having evidence of premature suture closure on the first CT scan. Multivariate logistic regression identified 2 risk factors, requiring invasive ventilation at 6 months of age and fraction of inspired oxygen requirement at 6 months of age. Increased head circumference at birth protected against the development of calvarial thickening.

CONCLUSIONS

We have described a novel subset of patients with chronic lung disease of prematurity who have calvarial thickening with remarkably high rates of premature closure of cranial sutures. The exact etiology of the association is unknown. In this patient population with radiographic evidence of premature suture closure, operative decision should be made after considering unequivocal evidence of elevated intracranial pressure or dysmorphology and balanced against the risk of the procedure.

Comparative Analysis of 2D and 3D Metrics for Evaluation of Postoperative Outcomes Following Endoscopic Suturectomy for Sagittal Craniosynostosis

To assess whether 3-dimensional (3D) volumetrics can be used to track and evaluate postoperative course of patients treated with endoscopic suturectomy for nonsyndromic sagittal synostosis, we compared changes in 2-dimensional (2D) measurements along with 3D volumetric correlates throughout the period of helmet therapy. Forty-six patients treated at our institution with endoscopic suturectomy for sagittal synostosis were retrospectively reviewed. Head circumference (HC), cephalic index (CI), and total cranial volumes (TCVs) were measured at 3 timepoints following surgery using optical surface scans obtained for helmet orthotics. All measurements showed significant differences between timepoints on the analysis of variance ( P <0.001). There was a significant correlation between CI and TCV (r=0.35, P =0.004) and between HC and TCV (r=0.81, P <0.001). The normalized rate of change over the course of treatment was significantly higher for TCV (36.7%) than for CI (8.8%) and HC (8.4%, P <0.001), with no difference between HC and CI. The authors conclude that 3D metrics were able to reliably follow the course of postoperative 2D metrics. There was a direct and linear correlation between HC and CI with TCV. Total cranial volumes showed the highest rate of sustained change at every timepoint. Although CI and HC plateau after the first measurement, TCV continues to adapt over the course of treatment. These results demonstrate the feasibility and value of volumetrics from 3D imaging to provide a more comprehensive evaluation of postoperative surgical outcomes than traditional 2D metrics without the ionizing radiation traditionally utilized for CT to obtain 3D metrics.

Efficacy of Systematic Early-Second-Trimester Ultrasound Screening for Facial Anomalies: A Comparison between Prenatal Ultrasound and Postmortem Findings

Second-trimester 2D ultrasound (US) assessment of the fetal anatomy, as proposed by worldwide guidelines, allows detecting the majority of fetal malformation. However, the detection rates of fetal facial anomalies seem to still be low, mostly in cases of isolated facial malformation. The purpose of this research was to assess and analyze the concordance between the antenatal imaging findings from second-trimester US screening and the results of fetal postmortem autopsy. Between January 2010 and January 2020, there were 43 cases where fetuses with prenatal ultrasound diagnosis of a face abnormality, associated or not with a genetic syndrome or chromosomal disorder, following intrauterine death (IUD) or termination of pregnancy (TOP) after the 13 weeks of pregnancy, underwent autopsy in the Pathological Anatomy section of Bari Polyclinic specializing in feto-placental autopsies. The diagnosis of the fetal facial defects at ultrasound was compared with the findings at autopsy in all cases. A very high level of agreement between prenatal ultrasound and autopsy findings was found for facial abnormalities associated with genetic syndromes or numerical abnormality of chromosomes. A lower level of concordance was instead found in isolated facial defects or those associated with other organ anomalies, but not associated with genetic syndrome or numerical chromosome anomaly. A detailed examination of aborted fetuses led to successful quality control of early-second-trimester ultrasound detection of facial anomalies; however, it was less accurate for the isolated ones. It is, thus, reasonable to propose a systematic early-second-trimester prenatal ultrasound screening for facial anatomy by operators specialized in fetal medicine field, using 2D, 3D, and 4D techniques (two-, three-, and four-dimensional ultrasound).

Lineage-specific mutation of Lmx1b provides new insights into distinct regulation of suture development in different areas of the calvaria

The calvaria (top part of the skull) is made of pieces of bone as well as multiple soft tissue joints called sutures. The latter is crucial to the growth and morphogenesis of the skull, and thus a loss of calvarial sutures can lead to severe congenital defects in humans. During embryogenesis, the calvaria develops from the cranial mesenchyme covering the brain, which contains cells originating from the neural crest and the mesoderm. While the mechanism that patterns the cranial mesenchyme into bone and sutures is not well understood, function of Lmx1b, a gene encoding a LIM-domain homeodomain transcription factor, plays a key role in this process. In the current study, we investigated a difference in the function of Lmx1b in different parts of the calvaria using neural crest-specific and mesoderm-specific Lmx1b mutants. We found that Lmx1b was obligatory for development of the interfrontal suture and the anterior fontanel along the dorsal midline of the skull, but not for the posterior fontanel over the midbrain. Also, Lmx1b mutation in the neural crest-derived mesenchyme, but not the mesoderm-derived mesenchyme, had a non-cell autonomous effect on coronal suture development. Furthermore, overexpression of Lmx1b in the neural crest lineage had different effects on the position of the coronal suture on the apical part and the basal part. Other unexpected phenotypes of Lmx1b mutants led to an additional finding that the coronal suture and the sagittal suture are of dual embryonic origin. Together, our data reveal a remarkable level of regional specificity in regulation of calvarial development.

Postoperative computed tomography imaging of pediatric patients with craniosynostosis: radiation dose and image quality comparison between multi-slice computed tomography and O-arm cone-beam computed tomography

BACKGROUND

When postoperative multi-slice computed tomography (MSCT) imaging of patients with craniosynostosis is used, it is usually performed a few days after surgery in a radiology department. This requires additional anesthesia for the patient. Recently, intraoperative mobile cone-beam CT (CBCT) devices have gained popularity for orthopedic and neurosurgical procedures, which allows postoperative CT imaging in the operating room.

OBJECTIVE

This single-center retrospective study compared radiation dose and image quality of postoperative imaging performed using conventional MSCT scanners and O-arm CBCT.

MATERIALS AND METHODS

A total of 104 pediatric syndromic and non-syndromic patients who were operated on because of single- or multiple-suture craniosynostosis were included in this study. The mean volumetric CT dose index (CTDIvol) and dose-length product (DLP) values of optimized craniosynostosis CT examinations (58 MSCT and 46 CBCT) were compared. Two surgeons evaluated the subjective image quality.

RESULTS

CBCT resulted in significantly lower CTDIvol (up to 14%) and DLP (up to 33%) compared to MSCT. Multi-slice CT image quality was considered superior to CBCT scans. However, all scans were considered to be of sufficient quality for diagnosis.

CONCLUSION

The O-arm device allowed for an immediate postoperative CBCT examination in the operating theater using the same anesthesia induction. Radiation exposure was lower in CBCT compared to MSCT scans, thus further encouraging the use of O-arms. Cone-beam CT imaging with an O-arm is a feasible method for postoperative craniosynostosis imaging, yielding less anesthesia to patients, lower health costs and the possibility to immediately evaluate results of the surgical operation.

Transcriptomic Signatures of Single-Suture Craniosynostosis Phenotypes

Craniosynostosis is a birth defect where calvarial sutures close prematurely, as part of a genetic syndrome or independently, with unknown cause. This study aimed to identify differences in gene expression in primary calvarial cell lines derived from patients with four phenotypes of single-suture craniosynostosis, compared to controls. Calvarial bone samples (N = 388 cases/85 controls) were collected from clinical sites during reconstructive skull surgery. Primary cell lines were then derived from the tissue and used for RNA sequencing. Linear models were fit to estimate covariate adjusted associations between gene expression and four phenotypes of single-suture craniosynostosis (lambdoid, metopic, sagittal, and coronal), compared to controls. Sex-stratified analysis was also performed for each phenotype. Differentially expressed genes (DEGs) included 72 genes associated with coronal, 90 genes associated with sagittal, 103 genes associated with metopic, and 33 genes associated with lambdoid craniosynostosis. The sex-stratified analysis revealed more DEGs in males (98) than females (4). There were 16 DEGs that were homeobox (HOX) genes. Three TFs (SUZ12, EZH2, AR) significantly regulated expression of DEGs in one or more phenotypes. Pathway analysis identified four KEGG pathways associated with at least one phenotype of craniosynostosis. Together, this work suggests unique molecular mechanisms related to craniosynostosis phenotype and fetal sex.

The Need for Additional Surgery after Passive versus Active Approaches to Syndromic Craniosynostosis: A Meta-analysis

Endoscopically assisted craniofacial surgery (EACS) has numerous advantages over traditional, open approaches, such as fronto-orbital advancement in treating nonsyndromic craniosynostosis. However, several articles report high reoperation rates in syndromic patients treated with EACS. This meta-analysis and review examines undesirable outcome rates (UORs), defined as reoperation or Whitaker category III/IV, in syndromic patients undergoing primary EACS compared with procedures that actively expand the cranial vault.

Methods

PubMed and Embase were searched in June 2022 to identify all articles reporting primary reoperation or Whitaker outcomes for syndromic patients undergoing cranial vault expanding surgery or suturectomy. A meta-analysis of proportions was performed comparing UORs, and a trim-and-fill adjustment method was used to validate sensitivity and assess publication bias.

Results

A total of 721 articles were screened. Five EACS articles (83 patients) and 22 active approach articles (478 patients) met inclusion criteria. Average UORs for EACS and active approaches were 26% (14%-38%) and 20% (13%-28%), respectively (P = 0.18). Reoperation occurred earlier in EACS patients (13.7 months postprimary surgery versus 37.1 months for active approaches, P = 0.003). Relapse presentations and reason for reoperation were also reviewed. Subjectively, EACS UORs were higher in all syndromes except Apert, and Saethre-Chotzen patients had the highest UOR for both approaches.

Conclusions

There was no statistically significant increase in UORs among syndromic patients treated with EACS compared with traditional approaches, although EACS patients required revision significantly sooner. Uncertainties regarding the long-term efficacy of EACS in children with syndromic craniosynostosis should be revisited as more data become available.

Synchondrosis fusion contributes to the progression of postnatal craniofacial dysmorphology in syndromic craniosynostosis

Syndromic craniosynostosis (CS) patients exhibit early, bony fusion of calvarial sutures and cranial synchondroses, resulting in craniofacial dysmorphology. In this study, we chronologically evaluated skull morphology change after abnormal fusion of the sutures and synchondroses in mouse models of syndromic CS for further understanding of the disease. We found fusion of the inter-sphenoid synchondrosis (ISS) in Apert syndrome model mice (Fgfr2^S252W/+ ) around 3 weeks old as seen in Crouzon syndrome model mice (Fgfr2c^C342Y/+ ). We then examined ontogenic trajectories of CS mouse models after 3 weeks of age using geometric morphometrics analyses. Antero-ventral growth of the face was affected in Fgfr2^S252W/+ and Fgfr2c^C342Y/+ mice, while Saethre-Chotzen syndrome model mice (Twist1^+/- ) did not show the ISS fusion and exhibited a similar growth pattern to that of control littermates. Further analysis revealed that the coronal suture synostosis in the CS mouse models induces only the brachycephalic phenotype as a shared morphological feature. Although previous studies suggest that the fusion of the facial sutures during neonatal period is associated with midface hypoplasia, the present study suggests that the progressive postnatal fusion of the cranial synchondrosis also contributes to craniofacial dysmorphology in mouse models of syndromic CS. These morphological trajectories increase our understanding of the progression of syndromic CS skull growth.

CT-like MR-derived Images for the Assessment of Craniosynostosis and other Pathologies of the Pediatric Skull

PURPOSE

To evaluate the diagnostic value of CT-like images based on a 3D T1-weighted spoiled gradient echo-based sequence (T1SGRE) for the visualization of the pediatric skull and the identification of pathologies, such as craniosynostosis or fractures.

METHODS

In this prospective study, 20 patients with suspected craniosynostosis (mean age 1.26 ± 1.38 years, 10 females) underwent MR imaging including the T1SGRE sequence and 2 more patients were included who presented with skull fractures (0.5 and 6.3 years, both male). Additionally, the skull of all patients was assessed using radiography or CT in combination with ultrasound. Two radiologists, blinded to the clinical information, evaluated the CT-like images. The results were compared to the diagnosis derived from the other imaging modalities and intraoperative findings. Intrarater and interrater agreement was calculated using Cohen's κ.

RESULTS

Of the 22 patients 8 had a metopic, 4 a coronal and 2 a sagittal craniosynostosis and 2 patients showed a complex combination of craniosynostoses. The agreement between the diagnosis based on the T1SGRE and the final diagnosis was substantial (Cohen's κ = 0.92, 95% confidence interval (CI) 0.77-1.00 for radiologist 1 and κ = 0.76, CI 0.51-1.00 for radiologist 2). Of the patients with fractures, one presented with a ping pong fracture and one with a fracture of the temporal bone. Both radiologists could identify the fractures using the T1SGRE.

CONCLUSION

The visualization of the pediatric skull and the assessment of sutures using a CT-like T1SGRE MR-sequence is feasible and comparable to other imaging modalities, and thus may help to reduce radiation exposure in pediatric patients. The technique may also be a promising imaging tool for other pathologies, such as fractures.

Cognitive performance in preschoolers with non-syndromic craniosynostosis undergoing surgery: A comparison with typically developing children

This study aimed to determine the cognitive profile of preschool children undergoing surgery to correct non-syndromic craniosynostosis, compare them with typically developing children, and analyze possible cognitive deficits in the most prevalent subtypes: sagittal and unicoronal. Thirty-one children aged 3 years to 5 years and 11 months with non-syndromic craniosynostosis (11 sagittal, 9 unicoronal, 4 metopic, 3 lambdoid, 4 multisutural) who underwent surgery were compared with thirty-one typically developing children. The Wechsler Preschool and Primary Scale of Intelligence-Third Edition (WPPSI-III) was used to assess cognitive function. Children with non-syndromic craniosynostosis scored below the typically developing children in the Verbal Intelligence Quotient (VIQ) and Full-Scale Intelligence Quotient (FISQ). When specific subtypes were compared, children with sagittal synostosis scored similarly to the typically developing children; in contrast, children with unicoronal synostosis had lower performance in the Processing Speed Quotient and FISQ. The proportion of participants scoring below one standard deviation on the VIQ, General Language Composite, and FISQ was greater in the non-syndromic craniosynostosis group. This study supports the finding that children with non-syndromic craniosynostosis, particularly those with unicoronal synostosis, have more cognitive difficulties than those with normal development. Assessing cognition at preschool age in children with non-syndromic craniosynostosis is important in order to detect difficulties before they become more apparent at school age.

Occlusal characteristics and oral health-related quality of life in adults operated due to sagittal synostosis in childhood: a case-control study with 26 years of follow-up

PURPOSE

The aim of this case-control study was to investigate occlusal characteristics, received orthodontic treatment, oral health-related quality of life (OHRQoL), and satisfaction with dental esthetics in adults operated due to sagittal synostosis.

METHODS

The study group consisted of 40 adults (25 males, 15 females, mean age 27.4 years, range 18-41) who were operated due to isolated sagittal synostosis in childhood. The control group comprised 40 age and gender-matched adults. Occlusal characteristics were evaluated clinically during study visits. Information on the previous orthodontic treatment was collected from dental records. OHRQoL was measured using the 14-item Oral Health Impact Profile (OHIP-14), and satisfaction with dental esthetics was evaluated using a visual analogue scale.

RESULTS

No statistically significant differences were found between the patient group and the controls in malocclusion traits (overjet, overbite, molar relationships, crossbite, scissor bite), previous orthodontic treatment, pre-treatment malocclusion diagnoses, OHIP variables, or satisfaction with dental esthetics. However, there was a tendency toward increased overjet and overbite in scaphocephalic patients.

CONCLUSION

It seems that adults with scaphocephaly operated in childhood do not differ from the average population in terms of occlusion, received orthodontic treatment, or oral health-related well-being.

SMAD6-deficiency in human genetic disorders

SMAD6 encodes an intracellular inhibitor of the bone morphogenetic protein (BMP) signalling pathway. Until now, SMAD6-deficiency has been associated with three distinctive human congenital conditions, i.e., congenital heart diseases, including left ventricular obstruction and conotruncal defects, craniosynostosis and radioulnar synostosis. Intriguingly, a similar spectrum of heterozygous loss-of-function variants has been reported to cause these clinically distinct disorders without a genotype–phenotype correlation. Even identical nucleotide changes have been described in patients with either a cardiovascular phenotype, craniosynostosis or radioulnar synostosis. These findings suggest that the primary pathogenic variant alone cannot explain the resultant patient phenotype. In this review, we summarise clinical and (patho)genetic (dis)similarities between these three SMAD6-related conditions, compare published Madh6 mouse models, in which the importance and impact of the genetic background with respect to the observed phenotype is highlighted, and elaborate on the cellular key mechanisms orchestrated by SMAD6 in the development of these three discrete inherited disorders. In addition, we discuss future research needed to elucidate the pathogenetic mechanisms underlying these diseases in order to improve their molecular diagnosis, advance therapeutic strategies and facilitate counselling of patients and their families.

Three-Dimensional Printed Polycaprolactone Mesh in Pediatric Cranial Vault Remodeling Surgery

BACKGROUND

The surgical management of craniosynostosis has greatly evolved with improvements in both technology and understanding of the disease process. Some drawbacks remain regarding bone regeneration within the surgical bony gaps. Generally, bony gaps improve in the 12 to 24 months after surgery, but some gaps may remain for longer and cause deformity and/or require additional bony reconstruction. These considerations make tissue-engineered bone very attractive. Novel 3-dimensional printed bioresorbable mesh implants made of Polycaprolactone (PCL) can be used to fill the surgical bony defects.

OBJECTIVES

The authors seek to investigate how the use of a 3-dimensional printed biodegradable PCL mesh applied to bony defects in cranial vault surgery affects bone healing.

METHODS

Case series analysis of 8 pediatric patients who have undergone surgical intervention using PCL mesh implants for reconstruction of bony defects during craniosynostosis correction surgery.

FINDINGS

Radiological evaluation of 3 patients at random time points between 9 and 12 months postoperative revealed persistent bony gaps in areas where PCL mesh was laid. One patient who underwent a subsequent cranial vault surgery at 9 months was found to have less bone regeneration in the defect area where PCL mesh was used when compared with an adjacent area where a particulate bone graft was used.

CONCLUSIONS

Based on our experience, the use of PCL mesh on its own did not augment bone regeneration. It is possible that a greater amount of time or increased vascularization of the scaffold is required, which supports the concept of regenerative matching axial vascularization or the further addition of osteogenic factors to increase the rate of bone formation.

Cranium growth, patterning and homeostasis

Craniofacial development requires precise spatiotemporal regulation of multiple signaling pathways that crosstalk to coordinate the growth and patterning of the skull with surrounding tissues. Recent insights into these signaling pathways and previously uncharacterized progenitor cell populations have refined our understanding of skull patterning, bone mineralization and tissue homeostasis. Here, we touch upon classical studies and recent advances with an emphasis on developmental and signaling mechanisms that regulate the osteoblast lineage for the calvaria, which forms the roof of the skull. We highlight studies that illustrate the roles of osteoprogenitor cells and cranial suture-derived stem cells for proper calvarial growth and homeostasis. We also discuss genes and signaling pathways that control suture patency and highlight how perturbing the molecular regulation of these pathways leads to craniosynostosis. Finally, we discuss the recently discovered tissue and signaling interactions that integrate skull and cerebrovascular development, and the potential implications for both cerebrospinal fluid hydrodynamics and brain waste clearance in craniosynostosis.

Intrafamilial variability in six family members with ERF-related craniosynostosis syndrome type 4

ERF-related craniosynostosis syndrome type 4 (CRS4, OMIM #600775) is a rare autosomal dominant malformation syndrome, caused by pathogenic variants in the ERF gene and characterized by craniosynostosis, developmental delay, and dysmorphic features such as hypertelorism, exophthalmos, depressed nasal bridge, and retrognathia. So far, there are mostly individual reports and only a few descriptions of families with more than two affected patients, allowing statements about the penetrance of a certain variant and its variability only to a limited extent. In this study, we report an in-depth analysis of the clinical course of six family members from three generations with the novel heterozygous nonsense variant c.286A>T (p.Lys96*) in the ERF gene. At the time of examination, all of the six patients showed mild dysmorphic features and brachydactyly, five were overweight/obese and had delayed speech development, and four were short in stature. Hyperactivity, a short concentration span and a history of learning difficulties were found in half of the affected family members. To this day, none of the patients developed increased intracranial hypertension that would require surgical intervention. This work provides further information on the expressive variability of an ERF variant in six members of one family and focuses on the need for close neuropediatric surveillance.

The Evolving Role of Next Generation Sequencing in Pediatric Neurosurgery: a Call for Action for Research, Clinical Practice, and Optimization of Care

NGS (Next-Generation Sequencing) is one of the most promising technologies that have truly revolutionized many aspects of clinical practice in recent years. It has been and is increasingly applied in many disciplines of medicine; however, it appears that pediatric neurosurgery despite its great potential has not truly embraced this new technology and is hesitant to employ it in its routine practice and guidelines. In this review, we briefly summarized the developments that lead to the establishment of NGS technology, reviewed the current applications and potentials of NGS in the disorders treated by pediatric neurosurgeons, and lastly discuss the steps we need to take to better harness NGS in pediatric neurosurgery.

Scaphocephaly and increased intra-cranial pressure in non-operated adults: A controlled anthropological study on 21 skulls

AIM AND SCOPE

The prevalence of increased intra-cranial pressure (ICP) in patients with scaphocephaly is controversial. Here, based on anthropological material, we aimed to determine whether adults with non-operated sagittal synostosis show indirect signs of increased ICP.

MATERIALS AND METHODS

Thirty-eight dry skulls (21 skulls with sagittal craniosynostosis and 17 controls) were selected from the collections of the National Museum of Natural History (Paris, France). All skulls registered as 'fused sagittal suture' or 'scaphocephaly' in the registry of the Museum were included. All had total fusion of the sagittal suture. Controls were selected within skulls of similar origin (France), without visible craniofacial anomalies. The 38 skulls were CT-scanned using a standard medical CT-scan with a protocol dedicated to dry bone imaging. Eight radiological signs associated with raised ICP were assessed: (1) calvaria and (2) skull base thinning, (3) dorsum sellae erosion, (4) sella turcica lengthening, (5) copper beaten skull, (6) suture diastasis, (7) persistent metopic suture, and (8) small frontal sinus. Scaphocephaly was assessed based on head circumference, cranial index, intra-cranial volume, fronto-nasal angle, and inter-zygomatic distance. Linear and non-linear logistic models were used to compare groups.

RESULTS

19/21 skulls with sagittal synostosis were significantly scaphocephalic. None of the criteria for ICP were significantly different in skulls with scaphocephaly relative to controls. Nevertheless, 5 individual skulls with scaphocephaly had ≥ 3 signs in favor of a history of raised ICP. We do not report the significant prevalence of indirect signs of raised ICP in adults with scaphocephaly. These results do not allow ruling out a history of early raised ICP or of minor prolonged raised ICP. Even though our findings support the fact that scaphocephaly is not significantly associated with prolonged raised ICP, individual cases (5/21) with clear signs in favor of a history of brain compression indicate that scaphocephaly correction should be considered as a functional procedure until the production of clear evidence. Cognitive assessments of non-operated adult patients with scaphocephaly could contribute to tackle this recurring question in craniofacial surgery.

Multidisciplinary Care Considerations for Patients with Craniosynostosis

Infants and children with craniosynostosis require multidisciplinary care, and this is best accomplished when care is provided on a craniofacial team. Most patients with craniosynostosis will have non-syndromic presentations; however, longitudinal care remains critical to ensure appropriate growth and development throughout childhood. In patients with syndromic craniosynostoses, coordinated longitudinal care becomes even more paramount because of the high level of complexity across many different specialties or disciplines. Care delivery that includes perspective and expertise from multiple disciplines is important to help patients reach their full potential and optimal outcomes.

CNN-Based Classification of Craniosynostosis Using 2D Distance Maps

Craniosynostosis is a condition associated with the premature fusion of skull sutures affecting infants. 3D photogrammetric scans are a promising alternative to computed tomography scans in cases of single suture or nonsyndromic synostosis for diagnostic imaging, but oftentimes diagnosis is not automated and relies on additional cephalometric measure-ments and the experience of the surgeon. We propose an alternative representation of the infant's head shape created from 3D photogrammetric surface scans as 2D distance maps. Those 2D distance maps rely on ray casting to extract distances from a center point to the head surface, arranging them into a 2D image grid. We use the distance map for an original convolutional neural network (CNN)-based classification approach, which is evaluated on a publicly available synthetic dataset for benchmarking and also tested on clinical data. Qualitative differences of different head shapes can be ob-served in the distance maps. The CNN-based classifier achieves accuracies of 100 % on the publicly available synthetic dataset and 98.86 % on the clinical test set. Our distance map approach demonstrates the diagnostic value of 3D photogrammetry and the possibility of automatic, CNN-based diagnosis. Future steps include the improvement of the mapping method and testing the CNN on more pathologies.

Mother and Daughter Carrying of the Same Pathogenic Variant in FGFR2 with Discordant Phenotype

Craniosynostosis are a heterogeneous group of genetic conditions characterized by the premature fusion of the skull bones. The most common forms of craniosynostosis are Crouzon, Apert and Pfeiffer syndromes. They differ from each other in various additional clinical manifestations, e.g., syndactyly is typical of Apert and rare in Pfeiffer syndrome. Their inheritance is autosomal dominant with incomplete penetrance and one of the main genes responsible for these syndromes is FGFR2, mapped on chromosome 10, encoding fibroblast growth factor receptor 2. We report an FGFR2 gene variant in a mother and daughter who present with different clinical features of Crouzon syndrome. The daughter is more severely affected than her mother, as also verified by a careful study of the face and oral cavity. The c.1032G>A transition in exon 8, already reported as a synonymous p.Ala344 = variant in Crouzon patients, also activates a new donor splice site leading to the loss of 51 nucleotides and the in-frame removal of 17 amino acids. We observed lower FGFR2 transcriptional and translational levels in the daughter compared to the mother and healthy controls. A preliminary functional assay and a molecular modeling added further details to explain the discordant phenotype of the two patients.

A Radiation-Free Classification Pipeline for Craniosynostosis Using Statistical Shape Modeling

Background: Craniosynostosis is a condition caused by the premature fusion of skull sutures, leading to irregular growth patterns of the head. Three-dimensional photogrammetry is a radiation-free alternative to the diagnosis using computed tomography. While statistical shape models have been proposed to quantify head shape, no shape-model-based classification approach has been presented yet. Methods: We present a classification pipeline that enables an automated diagnosis of three types of craniosynostosis. The pipeline is based on a statistical shape model built from photogrammetric surface scans. We made the model and pathology-specific submodels publicly available, making it the first publicly available craniosynostosis-related head model, as well as the first focusing on infants younger than 1.5 years. To the best of our knowledge, we performed the largest classification study for craniosynostosis to date. Results: Our classification approach yields an accuracy of 97.8 %, comparable to other state-of-the-art methods using both computed tomography scans and stereophotogrammetry. Regarding the statistical shape model, we demonstrate that our model performs similar to other statistical shape models of the human head. Conclusion: We present a state-of-the-art shape-model-based classification approach for a radiation-free diagnosis of craniosynostosis. Our publicly available shape model enables the assessment of craniosynostosis on realistic and synthetic data.

Global Epidemiology of Craniosynostosis: A Systematic Review and Meta-Analysis

OBJECTIVE

Craniosynostosis leads to craniofacial deformity and may result in raised intracranial pressure, neurocognitive deficits, and psychosocial issues if left untreated. The global epidemiology of craniosynostosis is unknown. We conducted a meta-analysis to estimate global birth prevalence.

METHODS

PubMed, Embase, and Scopus were searched. Articles were screened by title and abstract and then full text. Meta-analysis of birth prevalence was conducted. Birth prevalence figures were combined with metrics detailing the number of births in 2019 to estimate the number of children worldwide born with craniosynostosis annually.

RESULTS

Of 1378 resultant articles, 24 studies were included, including 20 providing data for craniosynostosis overall and 9 for nonsyndromic craniosynostosis. World Health Organization regions of included studies were 9 (37.5%) European Region, 8 (33.3%) Region of the Americas, 4 (16.7%) Western Pacific region, 2 (8.3%) African Region, and 1 (4.2%) Eastern Mediterranean Region. Lower middle-income countries represented only 4% of study manuscripts. The overall birth prevalence of craniosynostosis was 5.9 per 10,000 live births (20 studies; 95% confidence interval [CI]: 3.9, 8.4; I² = 100%). The birth prevalence of nonsyndromic craniosynostosis was 5.2 per 10,000 live births (9 studies; 95% CI: 3.4, 7.3; I² = 98%). The number of children born globally with craniosynostosis in 2019 was estimated to be 84,665 (95% CI: 55,965, 120,540), including 72,857 (95% CI: 47,637, 120,280) with nonsyndromic craniosynostosis.

CONCLUSIONS

Craniosynostosis is a common condition that affects the neurocognitive and craniofacial skeletal development of children worldwide. Initiatives to scale up capacity for craniosynostosis epidemiologic research and clinical care are warranted, particularly in low- and middle-income countries.

The Simultaneous Use of Spring-Mediated Cranioplasty and Distraction Osteogenesis as a Safe Modality for Multi-Suture Craniosynostosis

ABSTRACT

Craniosynostosis caused by premature fusion of the cranial sutures most commonly involves a single suture. Less commonly, multiple sutures may fuse prematurely resulting in complex craniosynostosis. The authors present 1 case of a patient with unilateral sagittal and unilateral lambdoid craniosynostosis treated safely simultaneous with spring-mediated cranioplasty and distraction osteogenesis.

Evaluation of dental maturity in Muenke syndrome, Saethre-Chotzen syndrome, and TCF12-related craniosynostosis

OBJECTIVES

To determine whether dental maturity (dental development) was delayed in patients with Muenke syndrome, Saethre-Chotzen syndrome, and TCF12-related craniosynostosis, compared with a Dutch control group without syndromes.

MATERIALS AND METHODS

This study included 60 patients (38 patients with Muenke syndrome, 17 patients with Saethre-Chotzen syndrome, and 5 with TCF12-related craniosynostosis), aged 5.8-16.8 years that were treated at the Department of Oral Maxillofacial Surgery, Special Dental Care, and Orthodontics, in Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, the Netherlands. Dental age was calculated according to Demirjian's index of dental maturity. The control group included 451 children without a syndrome.

RESULTS

Compared with the control group, dental development was delayed by an average of one year in 5- to 8-year-old patients with Muenke syndrome (P = 0.007) and in 8- to 10-year-old patients with Saethre-Chotzen syndrome (P = 0.044), but not in patients with TCF12-related craniosynostosis.

CONCLUSIONS

Our results indicated that dental development was delayed by one year, on average, in patients with Muenke syndrome and Saethre-Chotzen syndrome, compared with a Dutch control group without syndromes.

IMPLICATIONS

Our findings have improved the understanding of dental development in patients with Muenke and Saethre-Chotzen syndrome. These results can provide guidance on whether the orthodontist needs to consider growth disturbances related to dental development.

Targeted Sequencing of Candidate Regions Associated with Sagittal and Metopic Nonsyndromic Craniosynostosis

Craniosynostosis (CS) is a major birth defect in which one or more skull sutures fuse prematurely. We previously performed a genome-wide association study (GWAS) for sagittal non-syndromic CS (sNCS), identifying associations downstream from BMP2 on 20p12.3 and intronic to BBS9 on 7p14.3; analyses of imputed variants in DLG1 on 3q29 were also genome-wide significant. We followed this work with a GWAS for metopic non-syndromic NCS (mNCS), discovering a significant association intronic to BMP7 on 20q13.31. In the current study, we sequenced the associated regions on 3q29, 7p14.3, and 20p12.3, including two candidate genes (BMP2 and BMPER) near some of these regions in 83 sNCS child-parent trios, and sequenced regions on 7p14.3 and 20q13.2-q13.32 in 80 mNCS child-parent trios. These child-parent trios were selected from the original GWAS cohorts if the probands carried at least one copy of the top associated GWAS variant (rs1884302 C allele for sNCS; rs6127972 T allele for mNCS). Many of the variants sequenced in these targeted regions are strongly predicted to be within binding sites for transcription factors involved in craniofacial development or bone morphogenesis. Variants enriched in more than one trio and predicted to be damaging to gene function are prioritized for functional studies.

Neurocognitive outcomes of children with non-syndromic single-suture craniosynostosis

While the focus of craniosynostosis surgery is to improve head shape, neurocognitive sequelae are common and are incompletely understood. Neurodevelopmental problems that children with craniosynostosis face include cognitive and language impairments, motor delays or deficits, learning disabilities, executive dysfunction, and behavioral problems. Studies have shown that children with multiple suture craniosynostosis have more impairment than children with single-suture craniosynostosis. Children with isolated single-suture subtypes of craniosynostosis such as sagittal, metopic, and unicoronal craniosynostosis can have distinct neurocognitive profiles. In this review, we discuss the unique neurodevelopmental profiles of children with single-suture subtypes of craniosynostosis.