The increase of metopic synostosis: a pan-European observation

Piezosurgery in endoscopic-assisted trigonocephaly correction: a technical note

PURPOSE

This study aims to evaluate the effectiveness of the Piezosurgery® device in endoscopic-assisted correction of trigonocephaly. Trigonocephaly is a type of craniosynostosis characterized by a triangular-shaped forehead due to the premature fusion of the metopic suture. Traditional open cranial vault reconstruction, although common, is invasive and poses risks. The study explores a less invasive alternative using ultrasonic microvibrations for bone cutting, potentially reducing soft tissue damage and improving surgical outcomes.

METHODS

The Piezosurgery® device was employed in endoscopic trigonocephaly correction surgeries performed on patients under 4 months old at the French Referral Center for Craniosynostosis in Lyon. The technique involves making a small skin incision and performing osteotomies from the anterior fontanel to the glabella. A rigid 0° endoscope provides visibility, and the Piezosurgery® device enables precise bone cutting while preserving the dura mater. Post-surgery, patients were discharged within 3 days and required to wear a remodeling helmet for 6-8 months.

RESULTS

The use of Piezosurgery® device allowed precise osteotomies with minimal soft tissue damage. No dura mater injuries occurred in the patient series. The procedure was efficient, with an average duration of 80 min, and blood loss was minimal, reducing the need for blood transfusions. The endoscopic approach facilitated shorter surgical times and reduced postoperative infection risks. Enhanced visibility during surgery, due to cavitation effects, improved the accuracy of bone cuts. The technique demonstrated promising safety and esthetic outcomes, although it incurred higher costs compared to traditional methods.

CONCLUSION

Piezosurgery® device provides a safe and effective method for minimally invasive endoscopic correction of trigonocephaly. The device's ability to selectively cut bone while preserving soft tissues offers significant advantages, despite longer surgical times and higher costs. This technique represents a viable alternative to traditional open surgery, promoting better clinical outcomes and reduced recovery times.

Metopic craniosynostosis: Dynamic cranioplasty for trigonocephaly versus fronto-orbital remodeling and advancement - A retrospective study

The aim of this study was to compare a traditional fronto-orbital remodeling and advancement (FORA) with the dynamic cranioplasty for trigonocephaly (DCT). The authors analyzed patients who underwent surgery for trigonocephaly. Perioperative data were compared. Parents were asked to use a visual analog scale to evaluate the pre- and postoperative distance between the eyes, the forehead shape, and the global appearance of the face. A panel of observers was asked to grade pre- and postoperative photographs using a similar visual analog scale. Pre- and postoperative anthropometric data were collected and analyzed in a subset of the study population aged 9 years or older. The total sample size was 51 patients (DCT n = 39; FORA n = 12). Durations of surgery and anesthesia were shorter in the DCT group (115 vs 194 min, p = 0.001; 226 vs 289 min, p = 0.001). Patients in the DCT group received similar preoperative ratings to those in the FORA group, but significantly higher postoperative ratings by parents for all three questions. There were no significant differences in postoperative ratings by the panel or postoperative anthropometric data. DCT is safe and effective. It is preferred over FORA because it is associated with shorter durations of surgery and anesthesia, while providing higher degrees of parental satisfaction and similar aesthetic and anthropometric outcomes.

Comparison of emotional and behavioral regulation between metopic and sagittal synostosis

PURPOSE

Children with surgically corrected nonsyndromic craniosynostosis have been previously found to have neurocognitive and behavioral difficulties. Children with metopic synostosis have been described to have more difficulties than children with sagittal synostosis. This study aims to characterize the behavioral differences between children with metopic and sagittal synostosis.

METHODS

Children with metopic and sagittal synostosis were recruited at school age. Parents completed four separated behavioral assessments: Conners-3 (evaluation of ADHD), Social Responsiveness Scale-2 (SRS-2: evaluation of autism), Behavior Rating Inventory of Executive Function-2 (BRIEF-2: evaluation of executive function), and Child Behavior Checklist (CBCL: evaluation of overall behavioral problems). Children underwent intelligence quotient (IQ) testing using the Wechsler Abbreviated Scale of Intelligence (WASI-II).

RESULTS

There were 91 children (45 with metopic and 46 with sagittal synostosis). More children with metopic synostosis reported requiring supportive services (57.7% vs 34.7%, p = 0.02) and more reached or exceeded borderline clinical levels of two executive function subscales of the BRIEF-2 (emotion regulation index: 33.3% vs 17.4%, p = 0.05; global executive composite: 33.3% vs 17.4%, p = 0.05). Children with sagittal synostosis had higher scores on the rule-breaking and externalizing problem subscales of the CBCL. Increasing age at surgery was associated with worse executive function scores.

CONCLUSIONS

A relationship between suture subtype and behavioral outcomes exists at school age. More children with metopic synostosis required social services indicating more overall difficulties. Children with metopic synostosis have more specific problems with executive function, while children with sagittal synostosis had more difficulties with externalizing behaviors.

Surgical strategy in treatment of metopic synostosis in a single centre experience: technical note and quantitative analysis of the outcomes

PURPOSE

Trigonocephaly is the most common craniosynostosis involving orbits. Although some degree of agreement has been reached regarding surgical timing and indications for treatment, there is no consensus regarding the ideal operative technique to guarantee an optimal morphological outcome. The purpose of this study is to describe both strategies and to compare morphological outcomes by means of morphological surface analysis obtained from three-dimensional (3D) stereophotogrammetry, with two different techniques.

METHODS

We retrospectively investigated 43 patients with metopic synostosis surgically treated between 2004 and 2020. Two different techniques were applied, addressed as technique A and B. Ten patients undergone postoperative 3d stereophotogrammetry were enrolled, and cephalometric measurements were taken and compared to a cohort of unaffected patients matched by age and gender.

RESULTS

Comparison of the groups demonstrated a hypercorrection of the metopic angle of the second technique, associated with a slightly lower correction of the interfrontoparietal diameter. The metopic angle showed to be significantly undercorrected with the first method.

CONCLUSIONS

Alternated barrel staving technique appears to be a quick and satisfactory method in cranial remodelling for metopic synostosis. It guarantees an optimal aesthetic result in the first years after surgery.

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.

A critical eye on metopic craniosynostosis: A retrospective study assessing orbital dysmorphology as a marker of disease

This investigation sought to ascertain whether orbital morphology could predict genuine metopic craniosynostosis (MCS). The study retrospectively analyzed preoperative three-dimensional computed tomography (3D-CT) scans of patients who underwent surgical correction for MCS. MCS severity was evaluated using the interfrontal angle (IFA). Orbital dysmorphology was assessed based on multiple angles, including supraorbital notches and nasion (SNS), infraorbital foramina and nasion (INI), zygomaticofrontal suture-supraorbital notch-dacryon (ZSD), and orbital long axis (OLA). Results were juxtaposed against age/gender-matched controls and individuals with non-synostotic metopic ridge (MR). The study included 177 patients: 68 MCS, 35 MR, and 74 control subjects. All orbital measurements exhibited significant differences across groups. IFA demonstrated a strong association with all orbital measurements, particularly SNS (B = 0.79, p < 0.001). SNS showed the highest area under the curve among orbital measurements (0.89). Using a 95% sensitivity threshold, the optimal diagnostic angle for SNS was 129.23° (specificity 54%, sensitivity 96%). These findings suggest a correlation between orbital dysmorphology and trigonocephaly severity. The observed dysmorphology manifested in a superomedially accentuated rotational pattern. Importantly, SNS angle predicted MCS, with an angle greater than 130° indicating <5% likelihood of MCS diagnosis. The simplicity of measuring SNS angle on any 3D-CT scan highlights its practical use for assisting with MCS diagnosis.

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.

Validating the Supraorbital Notch-Nasion-Supraorbital Notch Angle as a Marker for Metopic Craniosynostosis Severity

OBJECTIVE

Metopic craniosynostosis (MCS) can be difficult to differentiate from metopic ridge (MR) or normal frontal morphology. This study assess whether the supraorbital notch-nasion-supraorbital notch (SNS) angle can help identify MCS.

METHODS

Records of 212 patients with preoperative three-dimensional computed tomography scans were examined. The SNS angles, surgeon craniofacial dysmorphology rankings, and CranioRate metopic severity scores (MSSs) were compared with the Spearman rank correlation coefficient. Receiver operating characteristic (ROC) curves with Youden J-statistic and cross-validation of regression models assessed the ability of these measures to predict surgery.

RESULTS

A total of 212 patients were included, consisting of 78 MCS, 37 MR, and 97 controls. Both the mean SNS angle (MCS: 111.7 ± 10.7 degrees, MR: 126.0 ± 8.2 degrees, controls: 130.7 ± 8.8 degrees P < 0.001) and MSS (MCS: 5.9 ± 2.0, MR: 1.4 ± 1.9, controls: 0.2 ± 1.9, P < 0.001) were different among the cohorts. The mean SNS angle (111.5 ± 10.7 versus 129.1 ± 8.8, P < 0.001) was lower in those who had surgery and CranioRate score (5.9 ± 2.1 versus 0.8 ± 2.2, P < 0.001) was higher in those who underwent surgery. SNS angles were positively correlated with surgeon craniofacial dysmorphology rankings ( r = 0.41, P < 0.05) and CranioRate MSS ( r = 0.54, P < 0.05). The ROC curve requiring high sensitivity revealed an SNS angle of 124.8 degrees predicted surgery with a sensitivity of 88.7% and a specificity of 71.3%. A ROC curve using the CranioRate MCC values ≥3.19 predicted surgery with 88.7% sensitivity and 94.7% specificity.

CONCLUSION

Orbital dysmorphology in patients with MCS is well captured by the supraorbital-nasion angle. Both the SNS angle and CranioRate MSS scores accurately predict surgical intervention.

Multiscale mechanical characterisation of the craniofacial system under external forces

Premature fusion of craniofacial joints, i.e. sutures, is a major clinical condition. This condition affects children and often requires numerous invasive surgeries to correct. Minimally invasive external loading of the skull has shown some success in achieving therapeutic effects in a mouse model of this condition, promising a new non-invasive treatment approach. However, our fundamental understanding of the level of deformation that such loading has induced across the sutures, leading to the effects observed is severely limited, yet crucial for its scalability. We carried out a series of multiscale characterisations of the loading effects on normal and craniosynostotic mice, in a series of in vivo and ex vivo studies. This involved developing a custom loading setup as well as software for its control and a novel in situ CT strain estimation approach following the principles of digital volume correlation. Our findings highlight that this treatment may disrupt bone formation across the sutures through plastic deformation of the treated suture. The level of permanent deformations observed across the coronal suture after loading corresponded well with the apparent strain that was estimated. This work provides invaluable insight into the level of mechanical forces that may prevent early fusion of cranial joints during the minimally invasive treatment cycle and will help the clinical translation of the treatment approach to humans.

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.

Clomiphene Citrate and Enclomiphene Hydrochloride Exposure Is Associated With Interfrontal Suture Fusion in Zebrafish

Background: The last several decades have witnessed an increase in metopic craniosynostosis incidence. Population-based studies suggest that pharmacological exposure in utero may be responsible. This study examined effects of the fertility drug clomiphene citrate (CC) on calvarial development in an established model for craniofacial development, the zebrafish Danio rerio. Results: Zebrafish larvae were exposed to clomiphene citrate or its isomer enclomiphene for five days at key points during calvarial development. Larvae were then raised to adulthood in normal rearing water. Zebrafish were analyzed using whole-mount skeletal staining. We observed differential effects on survivability, growth and suture formation depending on the treatment. Treatments with CC or enclomiphene at 5.5 mm SL led to increased fusion of the interfrontal suture (p < .01) compared to controls. Conclusions: Exposure to fertility drugs appears to affect development of the cranial vault, specifically the interfrontal suture, in zebrafish. Further research is required to identify the signaling mechanisms at play. This work suggests that fertility drug treatment may contribute to the increased incidence of metopic craniosynostosis observed globally.

3D Photography to Quantify the Severity of Metopic Craniosynostosis

This study aims to determine the utility of 3D photography for evaluating the severity of metopic craniosynostosis (MCS) using a validated, supervised machine learning (ML) algorithm.

This single-center retrospective cohort study included patients who were evaluated at our tertiary care center for MCS from 2016 to 2020 and underwent both head CT and 3D photography within a 2-month period.

The analysis method builds on our previously established ML algorithm for evaluating MCS severity using skull shape from CT scans. In this study, we regress the model to analyze 3D photographs and correlate the severity scores from both imaging modalities.

14 patients met inclusion criteria, 64.3% male (n = 9). The mean age in years at 3D photography and CT imaging was 0.97 and 0.94, respectively. Ten patient images were obtained preoperatively, and 4 patients did not require surgery. The severity prediction of the ML algorithm correlates closely when comparing the 3D photographs to CT bone data (Spearman correlation coefficient [SCC] r = 0.75; Pearson correlation coefficient [PCC] r = 0.82).

The results of this study show that 3D photography is a valid alternative to CT for evaluation of head shape in MCS. Its use will provide an objective, quantifiable means of assessing outcomes in a rigorous manner while decreasing radiation exposure in this patient population.

Assessing craniofacial growth and form without landmarks: A new automatic approach based on spectral methods

We present a novel method for the morphometric analysis of series of 3D shapes, and demonstrate its relevance for the detection and quantification of two craniofacial anomalies: trigonocephaly and metopic ridges, using CT-scans of young children. Our approach is fully automatic, and does not rely on manual landmark placement and annotations. Our approach furthermore allows to differentiate shape classes, enabling successful differential diagnosis between trigonocephaly and metopic ridges, two related conditions characterized by triangular foreheads. These results were obtained using recent developments in automatic nonrigid 3D shape correspondence methods and specifically spectral approaches based on the functional map framework. Our method can capture local changes in geometric structure, in contrast to methods based, for instance, on global shape descriptors. As such, our approach allows to perform automatic shape classification and provides visual feedback on shape regions associated with different classes of deformations. The flexibility and generality of our approach paves the way for the application of spectral methods in quantitative medicine.

Epidemiology of Rare Craniofacial Anomalies: Retrospective Western Australian Population Data Linkage Study

OBJECTIVE

To describe birth prevalence of rare craniofacial anomalies and associations with antenatal and perinatal factors.

STUDY DESIGN

All live and stillbirths in Western Australia between 1980 and 2010 were identified from the Western Australian Birth Registrations and the Midwives Notification System (also provides information on antenatal and perinatal factors). Rare craniofacial anomalies (craniosynostosis, craniofacial microsomia, and others [Pierre Robin, Van der Woude, and Treacher Collins syndrome]) were ascertained from the Western Australian Register of Developmental Anomalies and linked to other data sources. Trends in prevalence, adjusted for sex and Indigenous status, were investigated by Poisson regression and presented as annual percent change (APC). Strengths of association of related factors were assessed using multivariable log-binomial regression adjusted for sex, Indigenous status, birth year, socioeconomic disadvantage, and remoteness and reported as risk ratios with 95% CIs.

RESULTS

There was a temporal increase in prevalence of metopic synostosis (APC 5.59 [2.32-8.96]) and craniofacial microsomia (Goldenhar syndrome) (APC 4.43 [1.94-6.98]). Rare craniofacial anomalies were more likely among infants born preterm, as twins or greater-order multiples, with growth restriction, to older parents, to mothers undertaking fertility treatments, and with pre-existing medical conditions, specifically epilepsy, diabetes, or hypothyroidism. Prenatal identification of rare craniofacial anomalies was uncommon (0.6%).

CONCLUSIONS

Our findings indicate a steady increase over time in prevalence of metopic synostosis and craniofacial microsomia (Goldenhar syndrome). Possible associations of fertility treatments and pre-existing maternal medical conditions with rare craniofacial anomalies require further investigation.

Incidence of Non-Syndromic and Syndromic Craniosynostosis in Sweden

ABSTRACT

Premature craniosynostosis is a rare condition, with a wide range of incidence estimations in the literature. The aim of this study was to establish the current incidence among the Swedish population. Since the surgical care for these children is centralized to the 2 centers of Sahlgrenska University Hospital and Uppsala University Hospital, the 2 craniofacial hospital registries were examined for surgically treated children, all having a computed tomography verified diagnosis. Results show an incidence of 7.7 cases per 10,000 live births, including 0.60/10,000 syndromic craniosynostosis. Due to information programs among health care staff and a system for early diagnosis through rapid communication, these results seem to mirror the true incidence of craniosynostosis in the Swedish population. The updated incidence data will facilitate healthcare planning and make future studies of possible changes in craniosynostosis incidence more accurate.

Consistency of Cranial Shape Measures Obtained From Laser Surface and Computed Tomography Imaging

OBJECTIVE

Children with cranial shape abnormalities are often subjected to radiation from computed tomography (CT) for evaluation and clinical decision making. The STARscanner Laser Data Acquisition System (Orthomerica, Orlando, FL) may be a noninvasive alternate. The purpose of this study is to determine whether the STARscanner provides valid and accurate cranial measurements compared to CT.

DESIGN

We performed an institutional review board-approved retrospective review of a prospectively maintained database of patients with metopic suture abnormalities from 2013 to 2016.

SETTING

Plastic surgery clinic in an institutional tertiary care center.

PATIENTS

Eight patients were included that presented with metopic suture abnormalities, age less than 1 year, and CT and STARscanner imaging within 30 days of one another.

MAIN OUTCOME MEASURES

Cranial measurements were collected twice from 3 scan types: STARscanner, CT windowed for soft tissue, and CT windowed for bone. Measurements included: intracranial volume, height, base width, maximum antero-posterior length, maximum medio-lateral width, and oblique diameters. Nested analysis of variance were performed to determine the proportion of error attributable to: between-subject variance, scan type, and rater.

RESULTS

Measurements from STARscanner and both CT scans windows were highly consistent, with less than 1% of total error attributable to scan type for all measures.

CONCLUSIONS

Cranial shape measurements obtained from STARscanner images are highly consistent with those obtained from CT scans. The STARscanner has added benefits of speed of acquisition, minimal cost, and lack of radiation.

Aberrant Morphologic Patterning of Combined Sagittal and Metopic Craniosynostosis

ABSTRACT

Combined sagittal and metopic craniosynostosis is an uncommon condition that may result in a wide spectrum of cranial morphologies. This occurs as a result of the compound effects of both prematurely fused sutures. The authors present an incidence of sagittal craniosynostosis with a specific altered head morphology, and delayed diagnosis that the authors believe occurred due to structural changes associated with concurrent metopic suture synostosis This patient underscores the limitations of relying on classic diagnostic patterns and highlights the critical role of noninvasive imaging in the diagnosis of craniosynostosis.

Quantifying Orthotic Correction of Trigonocephaly Using Optical Surface Scanning

ABSTRACT

Numerous publications describe techniques to measure trigonocephaly caused by metopic synostosis, but they are potentially hazardous for use in acquiring longitudinal data. Optical surface scanning technology can safely yield craniometrics but has not established a practical means for measuring objective morphological changes to trigonocephaly during the practical time constraints of a clinical visit. The purpose of this preliminary study was to evaluate a method for safely and repeatedly measuring frontal angle (FA) using technology available at multiple centers providing treatment with cranial remolding orthoses.Optical scans of infants who underwent endoscopic-assisted minimally-invasive craniectomy for repair of metopic synostosis with cranial remolding were retrospectively analyzed. A novel FA measurement technique "FA30" was developed based on repeatable, geometrically-related surface landmarks approximating the glabella and frontotemporali. Results were compared to a control group and categories of non-synostotic deformity. Inter-rater reliability was assessed for pre- and post-treatment scan measurements among separate clinicians.All trigonocephalic subjects (n = 5) had initial FA30 significantly lower than the control group and other cohorts (P < 0.001). During the course of orthotic cranial remolding following surgical release mean FA30 increased from 121.5° to 138.5° (P < 0.001), approaching the control group mean of 144.4°. Intraclass coefficient calculation showed high reliability (intraclass correlation coefficient: 0.993, 95% confidence interval: 0.957-0.998, P < 0.001), which was supported with Bland-Altman analyses of agreement.Optical surface scanning may provide a safe, accurate, and repeatable means to measure FA. Increase in FA30 demonstrates correction of trigonocephaly. The method presented enables expeditious reporting of treatment progress to the infant's surgeon and parents, and has potential for use in optimizing treatment outcomes at multiple centers.

Establishment of Objective Clinical Parameters for Assessment of Trigonocephaly: Are Caliper-Derived Clinical Measures Adequate?

OBJECTIVE

Objective clinical parameters characterizing the severity of trigonocephaly are essential given the concern for computerized tomography (CT) scans and radiation in infants. The present study seeks to develop a clinical tool by which to characterize trigonocephaly.

DESIGN

Retrospective cohort study.

SETTING

Tertiary academically affiliated children's medical center.

PARTICIPANTS

A retrospective review identified patients with trigonocephaly for whom surgery was recommended (group 1) and those with metopic ridging without significant trigonocephaly (group 2). Normal age-matched controls were also evaluated (group 3).

INTERVENTIONS

Cranial vault caliper measurements were compared across groups. Two ratios measuring anterior vault constriction were developed: (1) bitemporal width at the mid-forehead to the biparietal width, and (2) bitemporal width at the lateral brow to the biparietal width.

MAIN OUTCOME MEASURES

Bitemporal width to biparietal width (ratio).

RESULTS

Caliper measures were obtained from 19 patients in group 1, 8 patients in group 2, and 19 patients in group 3 (controls). Cranial indices were not significantly different across groups. The bitemporal width at the mid-forehead to the biparietal width ratio was significantly lower in group 1, with no difference between groups 2 and 3. The bitemporal width at the lateral brow to the biparietal width ratio was significantly different between all 3 groups, with group 1 < group 2 < group 3, respectively.

CONCLUSIONS

Bitemporal to biparietal ratios are a quantitative, objective clinical measure that can be used to differentiate patients with significant trigonocephaly from those with metopic ridging but no significant cranial deformity. These findings suggest that caliper-derived indices can assist in characterizing surgically relevant cranial vault deformities secondary to metopic synostosis and may circumvent CT-based analysis.

Evaluation of fronto-orbital reconstruction surgery for the treatment of metopic synostosis in Chinese population

PURPOSE

To evaluate the efficacy of fronto-orbit reconstruction surgery on pediatric metopic synostosis via an image-based 3D reconstruction in Chinese population.

METHODS

Thirty pediatric metopic synostosis patients who received fronto-orbital reconstruction surgery in the Children's Hospital of Nanjing Medical University, Department of Neurosurgery, from January 2007 to December 2018 were analyzed in the study. Here we use the Mimics 20.0 software to reconstruct patients' cranial thin-section CT scan images from pre- and post-operation and control groups. Then the data of intracranial volume, frontal volume, orbital hypertelorism, ECA, ZF, and ORA were analyzed using the paired t-test or Wilcoxon matched-pairs signed-ranks test.

RESULTS

The age of these patients was 15.83 ± 16.12 months. After surgery, the mean frontal volume was enlarged from 92.75 ± 26.97 to 138.62 ± 47.97 cm³ (P < 0.0001), and the intracranial volume was enhanced from 976.87 ± 230.83 to 1059.44 ± 217.98 cm³ (P < 0.0001). In the meantime, the ECA was changed from 108.02 ± 8.17 to 134 ± 5.59° (P < 0.0001). In line with the alteration of the parameters mentioned above, the head shapes in all patients were also significantly improved after the surgery with no obvious complications.

CONCLUSION

Fronto-orbit reconstruction surgery is a safe and effective treatment for pediatric metopic synostosis. Computer-aided 3D reconstruction could serve as a quantitative strategy to evaluate the efficacy of craniofacial surgery.

Metopic triangle osteotomy in trigonocephaly Piezosurgery: a technical variant to control metopic emissary veins

Premature fusion of the metopic suture results in trigonocephaly with variable degrees of anterior cranial fossa dysmorphia and craniofacial deformity. Different surgical corrective techniques that aim to reshape the forehead and enlarge the cranial volume have been described. Typical variations of the standard fronto-orbitary advancement carry the risk of relevant blood loss during frontal osteotomy, where paired emissary metopic veins are disrupted. The authors present a technical variant that preserves a bony triangle over the glabella to optimize control of these veins, which represent the major source of bleeding, and applies Piezosurgery to perform the osteotomies to minimize bone substance loss.

The video can be found here: https://vimeo.com/511536423.

Emissary veins and pericerebral cerebrospinal fluid in trigonocephaly: do they define a specific subtype?

INTRODUCTION

The premature fusion of the metopic suture may be associated with the presence of emissary veins (EV) and abnormally large pericerebral cerebrospinal fluid (CSF) spaces which suggest an associated focal disturbance in CSF dynamics. The incidence of such findings and their potential significance in terms of management of the disease have not been fully elucidated. The aim of this study is to investigate whether these phenomena identify specific subtypes of trigonocephaly. In such a direction, we evaluated the volume of the pericerebral CSF spaces and their relationship to the morphology ("Ω," "V," or flat type) of the prematurely fused metopic suture and to the value of the interfrontal angle value on the grounds of computed tomographic (CT) scan examinations.

METHOD

The preoperative brain CT scans of 74 children (52 boys, 22 girls) with trigonocephaly who had undergone fronto-orbital remodeling were evaluated. The volume of the pericerebral CSF spaces and the value of the interfrontal angle were calculated. The type of intracranial notch was studied and classified according to its shape on the preoperative CT scan: a groove "Ω," a ridge/"V" ridge or absent when flat and evidence of emissary veins related to the abnormally fused suture.

RESULTS

Preoperatively, an endocranial metopic groove or ridge was seen in 70% of the children. Emissary veins were identified in 34 of 74 patients (45%), at a mean distance of 2.04 cm (1.18-2.94 cm) from the nasion. The presence of large pericerebral CSF spaces significantly correlated with the presence of EV (p < 0.05), with the "Ω" type (p < 0.05) and with interfrontal angles under 134° (p < 0.005).

CONCLUSIONS

Metopic suture early fusion shows an association between EV, pericerebral CSF spaces, and the "Ω" groove appearance of the suture. This association identifies a specific subgroup in which the presence of emissary veins and large pericerebral CSF spaces is an indicator of local venous hypertension due to the sagittal sinus constriction within an osseous groove created by the abnormal suture fusion process. The implications for the surgical management and long-term results as compared to trigonocephalic children with small or absent normal peripheral spaces and EV are still to be determined.

New method for quantification of the relative severity and (a)symmetry of isolated metopic synostosis

Trigonocephaly is the result of premature fusion of the metopic suture and its severity can vary widely. However, there is no gold standard for quantification of the severity. This study was performed to quantify severity using the Utrecht Cranial Shape Quantifier (UCSQ) and to assess forehead symmetry. Nineteen preoperative non-syndromic trigonocephaly patients (age ≤1 year) were included for the analysis of severity and symmetry. Severity according to the UCSQ was based on the following combined variables: forehead width and relative skull elongation. The UCSQ was compared to the most established quantification methods. A high correlation was found between the UCSQ and visual score (r=0.71). Moderate to negligible correlation was found between the UCSQ and frontal angle, binocular distance, inter-ocular distance, and frontal stenosis. Additionally, correlation between the visual score and these established quantification methods was negligible. Assessment of the frontal peak (a)symmetry (ratio of right to left triangle area in the curve) showed a mean right versus left triangle area ratio of 1.4 (range 0.9-2.4). The results suggest that the UCSQ is appropriate for the quantification of severity based on the high correlation with clinical judgement. Furthermore, a larger triangle area right than left was unexpectedly found, indicating forehead asymmetry.

Craniometric Measurements and Surgical Outcomes in Trigonocephaly Patients Who Underwent Surgical Treatment

Objective

The aim of this study was to discuss the results of craniometric measurements and surgical treatments in patients operated for isolated trigonocephaly (TC) in light of the current literature.

Methods

A total of 18 cases who underwent surgery for isolated TC were included in the study. Age, gender, family history, follow-up time, complications, duration of surgery, surgical blood loss, and amount of blood replacement in these patients were recorded. Craniometric measurements such as metopic angle (MA), cephalic index (CI), interparietal distance (IPD), intercoronal distance (ICD), and their ratio to each other were evaluated according to pre-and postoperative parameters. Photographs of the patients were taken before and after the operation. The Whitaker classification and Kampf "aesthetic outcome staging" were used in the evaluations.

Results

The mean MA values after the operation increased to reach above 147 degrees in all cases. The average CI did not change. ICD measurement averages increased significantly. The average IPD/ICD ratio decreased due to the increase in ICD and the enlargement of the anterior fossa after the operation. According to the Whitaker classification and Kampf “aesthetic outcome staging” scale, 17 of our cases were at stage I, rated as perfect, and one was at stage II, rated as good.

Conclusion

Surgery performed at the appropriate time for TC yields cosmetically satisfactory results. Since potential neurological and cognitive morbidities occur mostly in school-age patients, long-term follow-up of the cases is required. Performing craniometric measurements enables patients to be evaluated with objective and measurable numerical data.

Three-dimensional photography for intraoperative morphometric analysis in metopic craniosynostosis surgery

PURPOSE

Surgical correction of metopic craniosynostosis typically involves open cranial vault remodeling. Accurate translation of the virtual surgical plan into the operating room is challenging due to the lack of tools for intraoperative analysis of the surgical outcome. This study aimed to evaluate the feasibility of using a hand-held 3D photography device for intraoperative evaluation and guidance during cranial vault surgical reconstruction.

METHODS

A hand-held structured light scanner was used for intraoperative 3D photography during five craniosynostosis surgeries, obtaining 3D models of skin and bone surfaces before and after the remodeling. The accuracy of this device for 3D modeling and morphology quantification was evaluated using preoperative computed tomography imaging as gold-standard. In addition, the time required for intraoperative 3D photograph acquisition was measured.

RESULTS

The average error of intraoperative 3D photography was 0.30 mm. Moreover, the interfrontal angle and the transverse forehead width were accurately measured in the 3D photographs with an average error of 0.72 degrees and 0.62 mm. Surgeon's feedback indicates that this technology can be integrated into the surgical workflow without substantially increasing surgical time.

CONCLUSION

Hand-held 3D photography is an accurate technique for objective quantification of intraoperative cranial vault morphology and guidance during metopic craniosynostosis surgical reconstruction. This noninvasive technique does not substantially increase surgical time and does not require exposure to ionizing radiation, presenting a valuable alternative to computed tomography imaging. The proposed methodology can be integrated into the surgical workflow to assist during cranial vault remodeling and ensure optimal surgical outcomes.

Quantitative outcomes of endoscopic strip craniectomy for metopic craniosynostosis in children with severe trigonocephaly

PURPOSE

To assess intermediate-term (> 3 years) outcomes of endoscopic strip craniectomy with postoperative helmet therapy (ESC + HT) for the treatment of infants with severe trigonocephaly.

METHODS

This retrospective study examined cranial morphology of consecutive patients with severe trigonocephaly treated with minimally invasive ESC + HT. Preoperative and follow-up clinical parameters were collected from patient charts. Interfrontal divergence angle (IFDA), a validated and accurate measure of forehead narrowing, was measured on preoperative CT scans and on preoperative and postoperative 2D photographs.

RESULTS

Seven patients (4 male, 3 female) were included with a mean age at surgery of 2.76 months (range 1.8 to 4.1 months) and mean clinical follow-up of 3.71 years (photographic follow-up 2.73 years). The mean operative time was 91.4 min, with a mean estimated blood loss (EBL) of 57.1 ml and mean hospital length of stay of 1.14 days. IFDA improved from 118.8° to 135.9° (p < 0.01), with the mean final measurement falling within normal limits. The head circumference percentile was not significantly changed in follow-up. There was a statistically significant improvement in the inner-to-outer canthal distance ratio (p = 0.01) in follow-up, showing an improvement in hypotelorism. There were no dural tears, CSF leaks, infections, or other significant surgical morbidities, and there were no serious complications related to the use of helmet therapy. All patients achieved excellent aesthetic results judged by photographic comparison.

CONCLUSION

This study demonstrated that patients treated with ESC + HT for metopic craniosynostosis showed measurable and significant improvement in forehead shape. This technique is a safe and effective alternative to more invasive surgical interventions.

Distinguishing craniomorphometric characteristics and severity in metopic synostosis patients

The decision about which metopic synostosis patients should undergo surgery remains controversial. Multiple measures for radiographic severity have been developed in order to determine the optimal criteria for treatment. The aim of this study was to perform an extensive craniomorphometric analysis of patients who underwent surgery for metopic synostosis to validate and compare the various severity scales developed for this non-syndromic craniosynostosis. A comparative morphometric analysis was performed using computed tomography scans of preoperative metopic synostosis patients (n=167) and normal controls (n=44). Measurements included previous and newly developed metopic severity indices. Volumetric and area analyses were used to determine the degree of anterior cranial area and potential volume restrictions. Of the severity indices measured, the frontal angle, endocranial bifrontal angle (EBF), adjusted EBF (aEBF), anterior cranial fossa angle, horizontal cone angle, and bitemporal/biparietal distance ratio were significantly different in the metopic subjects relative to controls overall. However, metopic index, orbital rim angle, foramen ovale distance, and cranial volume exhibited no significant difference from controls. Only the frontal angle and aEBF correlated with the changes in anterior cranial dimensions observed in metopic synostosis. In conclusion, the frontal angle and aEBF provide the most accurate measures of severity in metopic synostosis.

A Comparison of Intracranial Volumes and Metopic Index in Patients With Isolated Metopic Ridge, Metopic Craniosynostosis, and Normal Healthy Children

BACKGROUND

Previous research has shown that patients with metopic craniosynostosis have significantly reduced intracranial volumes (ICVs) compared to normal healthy children. Furthermore, the metopic index (ratio of midfrontozygomatic diameter to maximal cranial width) has been described as an anthropometric cranial index for patients with metopic craniosynostosis. We aimed to determine whether patients with isolated metopic ridge have significantly different ICVs or metopic indices than normal children and patients with metopic craniosynostosis.

METHODS

A retrospective chart review of all patients with a diagnosis of a metopic ridge or metopic craniosynostosis was performed from 2000 to 2015 at Rady Children's Hospital. Patients were grouped based on computed tomographic scans consistent with metopic craniosynostosis versus metopic ridge.

RESULTS

Data were available for 15 metopic ridge patients, 74 metopic craniosynostosis patients, and 213 normal patients. Mean metopic ridge ICV was greater than mean metopic craniosynostosis ICV at 4 to 6 months and 7 to 12 months. Controlling for age and sex, the difference in ICV associated with metopic ridging was 197.484 cm3 and 137.770 cm3 at 4 to 6 and 7 to 12 months, respectively. Similarly, mean metopic index was significantly greater in metopic ridge patients compared to mean metopic craniosynostosis at 4 to 6 months and at 7 to 12 months.

CONCLUSIONS

Our study provides volumetric and anthropometric data to support the hypothesis that isolated metopic ridge is an intermediate phenotype between metopic craniosynostosis and normal cranial anatomy. We hope that characterizing the spectrum of disease involving premature closure of the metopic suture with regard to ICV and metopic index will aid physicians in their management of patients with isolated metopic ridge.

Risk factors and time trends for isolated craniosynostosis

BACKGROUND

We sought to investigate associations between maternal/infant characteristics and isolated craniosynostosis as well as its subtypes sagittal, metopic, and coronal synostosis, and assess trends in the prevalence of these conditions.

METHODS

We identified cases in the Texas Birth Defects Registry from 1999 to 2014. We used Poisson regression to identify associations between maternal/infant characteristics and craniosynostosis. We used joinpoint regression and unadjusted Poisson regression to evaluate temporal trends. Finally, we computed adjusted Poisson models to evaluate whether temporal trends were evident after accounting for changes in the population distributions of maternal/infant characteristics over time.

RESULTS

Relative to all live births in the general population, cases were more frequently male or preterm. Mothers of cases were more frequently non-Hispanic white and more frequently obese. Non-Hispanic black or Hispanic maternal race/ethnicity was associated with a lower prevalence of all craniosynostosis subtypes. Previous live births were associated with sagittal synostosis; residence on the U.S.-Mexico border was associated with sagittal and coronal synostosis. The prevalence of any isolated craniosynostosis increased (average annual percent change estimated from joinpoint regression [AAPC]: 2.9%), as did the prevalences of sagittal (AAPC: 3.3%) and metopic synostosis (AAPC: 5.4%). In crude Poisson models, the same temporal trends were observed, however these were attenuated after adjusting for maternal/infant characteristics.

CONCLUSIONS

Prevalence of isolated craniosynostosis increased from 1999 to 2014. The largest AAPC was observed for metopic synostosis. Changes in the population distribution of associated maternal/infant characteristics may explain these trends.

Assessment of the Outcome of Calvarial Vault Remodeling and Spring-Mediated Cranioplasty in the Correction of Isolated Sagittal Suture Synostosis

BACKGROUND

Sagittal synostosis is the commonest form of nonsyndromic isolated craniosynostosis. Calvarial vault remodeling (CVR) and spring-mediated cranioplasty (SMC) are the commonly used correction techniques.

AIM OF THE WORK

To study and compare clinical and radiographic outcomes of CVR and SMC in the correction of isolated sagittal suture synostosis.

METHODS

A prospective cohort with the patients were divided into group; I (SMC) and II (CVR), each 15 patients. They were observed to evaluate the outcome and detect complications.

RESULTS

Mean operative time was 59.2 minutes in SMC and 184 minutes in CVR. Mean intraoperative blood loss was 26 mL in SMC and 64.7 mL in CVR. Intraoperative complications in SMC were dural tear in 1 patient and superior sagittal sinus injury in another patient, while in CVR 2 patients with dural tears and a 3rd with superior sagittal sinus injury. Postoperative complications in SMC were exposed spring, gaped wound, and parietal eminence elevation, while in CVR 2 patients needed blood transfusion. The mean hospital stays was 1.4 days in SMC and 4.1 days in CVR. In SMC, the relative increase in cephalic index varied between 5.5% and 8.2%, while for CVR, it varied between 5.1% and 7.9%.

CONCLUSION

The SMC and CVR are safe procedures, with good long-term results and significant objective changes toward normalization of the skull morphology in isolated sagittal craniosynostosis. The SMC is less invasive and associated with reduced hospital stays, decreased blood loss, and can be performed at a younger age than CVR with a lower morbidity.

Identifying the Misshapen Head: Craniosynostosis and Related Disorders

Pediatric care providers, pediatricians, pediatric subspecialty physicians, and other health care providers should be able to recognize children with abnormal head shapes that occur as a result of both synostotic and deformational processes. The purpose of this clinical report is to review the characteristic head shape changes, as well as secondary craniofacial characteristics, that occur in the setting of the various primary craniosynostoses and deformations. As an introduction, the physiology and genetics of skull growth as well as the pathophysiology underlying craniosynostosis are reviewed. This is followed by a description of each type of primary craniosynostosis (metopic, unicoronal, bicoronal, sagittal, lambdoid, and frontosphenoidal) and their resultant head shape changes, with an emphasis on differentiating conditions that require surgical correction from those (bathrocephaly, deformational plagiocephaly/brachycephaly, and neonatal intensive care unit-associated skill deformation, known as NICUcephaly) that do not. The report ends with a brief discussion of microcephaly as it relates to craniosynostosis as well as fontanelle closure. The intent is to improve pediatric care providers' recognition and timely referral for craniosynostosis and their differentiation of synostotic from deformational and other nonoperative head shape changes.

Epidemiology of craniosynostosis in Norway

OBJECTIVE

The authors present population-based epidemiological data for craniosynostosis regarding incidence, age at diagnosis, sex differences, and frequency of syndromic and familial cases.

METHODS

The prospective registry of the Norwegian National Unit for Craniofacial Surgery was used to retrieve data on all individuals with craniosynostosis treated between 2003 and 2017. The cohort was divided into three 5-year groups based on year of birth: 2003-2007, 2008-2012, and 2013-2017.

RESULTS

The authors identified 386 individuals with craniosynostosis. Of these, 328 (85%) consented to be registered with further information. The incidence increased significantly during the study period and was 5.5 per 10,000 live births (1/1800) in the last 5-year period. The increase was seen almost exclusively in the nonsyndromic group. Syndromic craniosynostosis accounted for 27% of the cases, and the incidence remained stable throughout the three 5-year periods. Both syndromic and nonsyndromic craniosynostosis were highly suture specific. There was a male preponderance (male/female ratio 2:1), and males accounted for 75% of the individuals with midline synostosis. Overall, 9.5% were index individuals in families with more than one affected member; of these, 73% were nonsyndromic cases.

CONCLUSIONS

The incidence of craniosynostosis increased during the study period, and the observed incidence is among the highest reported. The authors attribute this to increasing awareness among healthcare professionals. The number of syndromic cases was high, likely due to a broader definition compared to the majority of earlier reports. The study revealed a high number of familial cases in both syndromic and nonsyndromic craniosynostosis, thus highlighting the importance of genetics as an underlying cause of craniosynostosis.

Assessment of Epidemiological Trends in Craniosynostosis: Limitations of the Current Classification System

Craniosynostosis affects 1 in 2,000 live births, which makes it one of the most common craniofacial abnormalities in the United States. Despite this fact, few national epidemiologic reports exist, although US and European studies have reported an increased incidence of metopic craniosynostosis. The aim of our study is to analyze the National Inpatient Sample (NIS) to support those conclusions.

The Use of Eye Tracking to Discern the Threshold at Which Metopic Orbitofrontal Deformity Attracts Attention

INTRODUCTION AND OBJECTIVES

Surgical treatment for trigonocephaly aims to eliminate a stigmatizing deformity, yet the severity that captures unwanted attention is unknown. Surgeons intervene at different points of severity, eliciting controversy. This study used eye tracking to investigate when deformity is perceived.

MATERIAL AND METHODS

Three-dimensional photogrammetric images of a normal child and a child with trigonocephaly were mathematically deformed, in 10% increments, to create a spectrum of 11 images. These images were shown to participants using an eye tracker. Participants' gaze patterns were analyzed, and participants were asked if each image looked "normal" or "abnormal."

RESULTS

Sixty-six graduate students were recruited. Average dwell time toward pathologic areas of interest (AOIs) increased proportionally, from 0.77 ± 0.33 seconds at 0% deformity to 1.08 ± 0.75 seconds at 100% deformity (P < .0001). A majority of participants did not agree an image looked "abnormal" until 90% deformity from any angle.

CONCLUSION

Eye tracking can be used as a proxy for attention threshold toward orbitofrontal deformity. The amount of attention toward orbitofrontal AOIs increased proportionally with severity. Participants did not generally agree there was "abnormality" until deformity was severe. This study supports the assertion that surgical intervention may be best reserved for more severe deformity.

Craniofacial Sutural Pattern and Surgical Management in Patients With Different Degrees of Trigonocephaly Severity

The aim of this study was to identify quantitative tools to classify the severity of trigonocephaly to guide surgical management and predict outcome.

METHODS

We reviewed high-resolution computed tomography images of 59 patients with metopic synostosis. We assessed the craniofacial sutural pattern as well as interfrontal and metopic angles, and we related the frontal angulation degree with the sutural pattern, the surgical management, and clinical outcome.

RESULTS

We identified 3 groups according to the severity of trigonocephaly. No difference was found between the sutural pattern of nasion complex and severity, whereas the closure of zygomatic maxillary sutures increased with the severity degree (P < 0.05). The operative management was related to the severity degree (P < 0.001) and to the reduced age (P = 0.009).

CONCLUSIONS

Interfrontal and metopic angles are complementary measurements to evaluate with high accuracy the degree of frontal angulation. In preoperative assessment, they may guide surgery decision in particular when the choice is not straightforward.

Radiographic Severity of Metopic Craniosynostosis Correlates with Long-Term Neurocognitive Outcomes

BACKGROUND

Reports of neurodevelopmental delays in adolescents with metopic craniosynostosis have ranged from 15 to 61 percent. Previously, event-related potentials have correlated preoperative radiographic severity with language deficiencies in infancy. This study sought to characterize neurocognitive testing at cranial maturity and correlate outcomes to preoperative radiographic severity.

METHODS

Patients diagnosed with metopic craniosynostosis who underwent surgical correction in infancy completed a neurodevelopmental battery evaluating age-normalized intelligence quotient, academic achievement, and visuomotor integration. Data were stratified by preoperative endocranial bifrontal angle (moderate, >124 degrees; severe, <124 degrees). Multiple variable regression was used to control measured intelligence and achievement for age at surgery, age at testing, parental education, and income. Significance was set at p < 0.05.

RESULTS

Twenty patients completed neurodevelopmental testing. Mean intelligence quotient was 111.7 ± 13 and academic achievement was similar to national averages (word reading, 53.4 percent; reading comprehension, 53.4 percent; reading composite, 53.5 percent; spelling, 44 percent; and math, 52.9 percent). Radiographic measurements revealed 36 percent of patients with moderate phenotype and 64 percent with severe. Patients with severe phenotypes had lower intelligence quotient measures and scored more poorly in every academic measure tested. Word reading (113 versus 95; p = 0.035) and reading composite (109 versus 98; p = 0.014) reached significance.

CONCLUSIONS

Overall, cranial mature patients with metopic craniosynostosis had above average intelligence quotient and academic achievement near the national mean. Long-term neurocognitive function was correlated to preoperative radiographic severity in metopic craniosynostosis, with more severe cases performing worse.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Cost comparison of surgical management of nonsagittal synostosis: traditional open versus endoscope-assisted techniques

OBJECTIVE

Management of craniosynostosis at an early age is important for mitigating the risk of abnormal cranial development, but treatment can result in significant expenses. Previous research has shown that endoscope-assisted craniectomy (EAC) is less costly than open cranial vault remodeling (CVR) for patients with sagittal synostosis. The aim of this study was to strengthen the existing body of healthcare cost research by elucidating the charges associated with open and endoscopic treatment for patients with nonsagittal synostosis.

METHODS

The authors performed a retrospective analysis of data obtained in 41 patients who underwent open CVR and 38 who underwent EAC with postoperative helmet therapy for nonsagittal, single-suture craniosynostosis (metopic, coronal, and lambdoid) between 2008 and 2018. All patients were < 1 year of age at the time of surgery and had a minimum 1 year of follow-up. Inpatient charges, physician fees, helmet charges, and outpatient clinic visits in the 1st year were analyzed.

RESULTS

The mean ages of the children treated with EAC and open CVR were 3.5 months and 8.7 months, respectively. Patients undergoing EAC with postoperative helmet therapy required more outpatient clinic visits in the 1st year than patients undergoing CVR (4 vs 2; p < 0.001). Overall, 13% of patients in the EAC group required 1 helmet, 30% required 2 helmets, 40% required 3 helmets, and 13% required 4 or more helmets; the mean total helmeting charges were $10,072. The total charges of treatment, including inpatient charges, physician fees, outpatient clinic visit costs, and helmet charges, were significantly lower for the EAC group than they were for the open CVR group ($50,840 vs $95,588; p < 0.001).

CONCLUSIONS

Despite the additional charges for postoperative helmet therapy and the more frequent outpatient visits, EAC is significantly less expensive than open CVR for patients with metopic, coronal, and lambdoid craniosynostosis. In conjunction with the existing literature on clinical outcomes and perioperative resource utilization, these data support EAC as a cost-minimizing treatment for eligible patients with nonsagittal synostosis.

NGS targeted screening of 100 Scandinavian patients with coronal synostosis

Craniosynostosis (CS), the premature closure of one or more cranial sutures, occurs both as part of a syndrome or in isolation (nonsyndromic form). Here, we have studied the prevalence and spectrum of genetic alterations associated with coronal suture closure in 100 Scandinavian patients treated at a single craniofacial unit. All patients were phenotypically assessed and analyzed with a custom-designed 63 gene NGS-panel. Most cases (78%) were syndromic forms of CS. Pathogenic and likely pathogenic variants explaining the phenotype were found in 80% of the families with syndromic CS and in 14% of those with nonsyndromic CS. Sixty-five percent of the families had mutations in the CS core genes FGFR2, TWIST1, FGFR3, TCF12, EFNB1, FGFR1, and POR. Five novel pathogenic/likely pathogenic variants in TWIST1, TCF12, and EFNB1 were identified. We also found novel variants in SPECC1L, IGF1R, and CYP26B1 with a possible modulator phenotypic effect. Our findings demonstrate that NGS targeted sequencing is a powerful tool to detect pathogenic mutations in patients with coronal CS and further emphasize the importance of thorough assessment of the patient's phenotype for reliable interpretation of the molecular findings. This is particularly important in patients with complex phenotypes and rare forms of CS.

Recent Advances in Craniosynostosis

Craniosynostosis is a pathologic craniofacial disorder and is defined as the premature fusion of one or more cranial (calvarial) sutures. Cranial sutures are fibrous joints consisting of nonossified mesenchymal cells that play an important role in the development of healthy craniofacial skeletons. Early fusion of these sutures results in incomplete brain development that may lead to complications of several severe medical conditions including seizures, brain damage, mental delay, complex deformities, strabismus, and visual and breathing problems. As a congenital disease, craniosynostosis has a heterogeneous origin that can be affected by genetic and epigenetic alterations, teratogens, and environmental factors and make the syndrome highly complex. To date, approximately 200 syndromes have been linked to craniosynostosis. In addition to being part of a syndrome, craniosynostosis can be nonsyndromic, formed without any additional anomalies. More than 50 nuclear genes that relate to craniosynostosis have been identified. Besides genetic factors, epigenetic factors like microRNAs and mechanical forces also play important roles in suture fusion. As craniosynostosis is a multifactorial disorder, evaluating the craniosynostosis syndrome requires and depends on all the information obtained from clinical findings, genetic analysis, epigenetic or environmental factors, or gene modulators. In this review, we will focus on embryologic and genetic studies, as well as epigenetic and environmental studies. We will discuss published studies and correlate the findings with unknown aspects of craniofacial disorders.

In Situ Hinge Technique for the Frontal Bandeau for the Correction of Metopic Craniosynostosis Reduces Operative Time

BACKGROUND AND PURPOSE

Treatment of metopic craniosynostosis often involves bitemporal expansion of the anterior cranium. This report compares perioperative variables of a surgical technique in which the fronto-orbital bandeau is bent in situ to traditional fronto-orbital advancement and remodeling (FOAR).

METHOD/DESCRIPTION

Six patients undergoing the hinge technique were compared to the senior author's 6 most recent conventional FOARs. Study and control cohorts were reasonably well matched for age and sex; only those with nonsyndromic, single-suture metopic synostosis were included. Perioperative variables such as OR time, blood loss, hardware costs, length of stay, and perioperative complications were compared between groups using unpaired t tests.

RESULTS

Operative time was significantly decreased when the hinge technique was utilized, with a mean operative time of 159 ± 14.0 minutes for hinge patients and 193 ± 33.8 minutes for nonhinge patients (P = 0.049). Hardware was also significantly decreased from an average of 2.2 ± 1.0 plates and 35 ± 13.8 screws in nonhinge patients to 1 plate and 20 screws in each hinge patient (P < 0.02), for an average hardware saving of $2990 per hinge surgery (P = 0.019). Estimated blood loss, length of stay, and perioperative complications were not significantly different between groups. All patients in both groups had Whitaker 1 outcomes in short-term follow-up.

CONCLUSIONS

The hinge technique for the treatment of metopic synostosis is associated with a statistically significant decrease in operative time, hardware utilization, and hardware cost. Perioperative outcomes were similar between the hinge technique and traditional FOAR in the short term, and additional follow-up is needed to determine whether the 2 have similar long-term outcomes.

Practical Computed Tomography Scan Findings for Distinguishing Metopic Craniosynostosis from Metopic Ridging

Background:

Premature fusion of the metopic suture (ie, metopic craniosynostosis) can be difficult to discriminate from physiological closure of the metopic suture with ridging (MR). Yet, MCS is treated surgically, whereas MR is treated nonsurgically. Often, the diagnosis can be made by physical examination alone, but in difficult cases, a computed tomography (CT) scan can add additional diagnostic information.

Methods:

We de-identified, randomized, and analyzed the CT scans of patients with MCS (n = 52), MR (n = 20) and age-matched normative controls (n = 52) to identify specific findings helpful in distinguishing between MCS and MR. Four expert clinicians were blinded to the clinical diagnosis and assessed each CT for features of the orbits, frontal bones, and inner table of calvaria.

Results:

Although no single feature was diagnostic of MCS, we identified several signs that were correlated with MCS, MR, or controls. Features such as “posteriorly displaced frontal bone” and “frontal bone tangent to mid-orbit or medial” demonstrated higher correlation with MCS than MR and the addition of other features improves the accuracy of diagnosis as did inclusion of the interfrontal divergence angle.

Conclusion:

The presence of a closed metopic suture in addition to other CT scan findings may improve the accuracy of diagnosing MCS, MR, and normocephaly.

An Overview of Modelling Craniosynostosis Using the Finite Element Method

Craniosynostosis is a medical condition caused by the early fusion of the cranial joint. The finite element method (FEM) is a computational technique that can answer a variety of "what if" questions in relation to the biomechanics of this condition. The aim of this study was to review the current literature that has used FEM to investigate the biomechanics of any aspect of craniosynostosis, being its development or its reconstruction. This review highlights that a relatively small number of studies (n = 10) has used FEM to investigate the biomechanics of craniosynostosis. Current studies set a good foundation for the future to take advantage of this method and optimize reconstruction of various forms of craniosynostosis.

Control of metopic emissary veins in trigonocephaly surgery. Technical note

INTRODUCTION

Trigonocephaly with its premature fusion of the metopic synostosis is associated with a risk of cerebral compression and several craniofacial morphological deformations. Numerous surgical techniques have been proposed to enlarge and reshape the forehead. They all carry a risk of bleeding during osteotomies, especially in the region of the superior sagittal sinus (SSS) encased in the early fused suture and of the paired metopic transosseous emissary veins superior to the glabella, which is typical of this type of synostosis. In fact, these paired metopic transosseous veins are often, if not always, the source of major bleeding when torn during the elevation of the frontal flap.

TECHNICAL NOTE

A simple technical variant may prevent or at least easily control bleeding in this region during the early phases of the surgical repair. The technical variant to the standard surgical techniques utilized to correct trigonocephaly consists in preserving a triangle of bone above the glabella (about 4 cm at the base and 4 cm in height). The triangle of bone contains the initial segment of the SSS and the emissary metopic veins draining the frontal poles. After removing the frontal flap in a conventional manner, this technical variant allows to detach the veins as well as the SSS from the surrounding bone structures under direct visualization, also in case of vessels running partially encased in the bone. Once the venous structure is detached and hemostasis controlled, this last piece of frontal bone may be removed without unnecessary "iatrogenic" bleeding.

CONCLUSION

The propounded procedure does not prolong the surgical time significantly and does not require additional surgical skills or equipment.

BBS9 gene in nonsyndromic craniosynostosis: Role of the primary cilium in the aberrant ossification of the suture osteogenic niche

Nonsyndromic craniosynostosis (NCS) is the premature ossification of skull sutures, without associated clinical features. Mutations in several genes account for a small number of NCS patients; thus, the molecular etiopathogenesis of NCS remains largely unclear. Our study aimed at characterizing the molecular signaling implicated in the aberrant ossification of sutures in NCS patients. Comparative gene expression profiling of NCS patient sutures identified a fused suture-specific signature, including 17 genes involved in primary cilium signaling and assembly. Cells from fused sutures displayed a reduced potential to form primary cilia compared to cells from control patent sutures of the same patient. We identified specific upregulated splice variants of the Bardet Biedl syndrome-associated gene 9 (BBS9), which encodes a structural component of the ciliary BBSome complex. BBS9 expression increased during in vitro osteogenic differentiation of suture-derived mesenchymal cells of NCS patients. Also, Bbs9 expression increased during in vivo ossification of rat sutures. BBS9 functional knockdown affected the expression of primary cilia on patient suture cells and their osteogenic potential. Computational modeling of the upregulated protein isoforms (observed in patients) predicted that their binding affinity within the BBSome may be affected, providing a possible explanation for the aberrant suture ossification in NCS.

Comparison of an unsupervised machine learning algorithm and surgeon diagnosis in the clinical differentiation of metopic craniosynostosis and benign metopic ridge

Metopic suture closure can manifest as a benign metopic ridge (BMR), a variant of normal, to “true” metopic craniosynostosis (MCS), which is associated with severe trigonocephaly. Currently, there is no gold standard for how much associated orbitofrontal dysmorphology should trigger surgical intervention. In our study, we used three-dimensional (3D) curvature analysis to separate the phenotypes along the spectrum, and to compare surgeons’ thresholds for operation. Three-dimensional curvature analyses on 43 subject patients revealed that the mean curvature of mid-forehead vertical ridge was higher for patients who underwent operation than those who did not undergo operation by 1.3 m⁻¹ (p < 0.0001). In addition, these patients had more retruded supraorbital areas by −16.1 m⁻¹ (p < 0.0001). K-means clustering classified patients into two different severity groups, and with the exception of 2 patients, the algorithm’s classification of deformity completely agreed with the surgeons’ decisions to offer either conservative or operative therapy (i.e. 96% agreement). The described methods are effective in classifying severity of deformity and in our experience closely approximate surgeon therapeutic decision making. These methods offer the possibility to consistently determine when surgical intervention may be beneficial and to avoid unnecessary surgeries on children with benign metopic ridge and associated minimal orbitofrontal deformity.

Subsegmental Osteotomy Technique With Distraction Osteogenesis for Natural Frontal Contouring in Metopic Synostosis

Vectoring issues occur due to the dynamics of unidirectional procedure that is selected. To circumvent such difficulties, we have devised subsegmental osteotomy with distraction. In our technique, frontal bone flap was divided into 4 segments that were linked to each other by suturing wires in an 8-year-old patient with trigonocephaly. Subsegmental osteotomy and wiring of bone flap enabled us to slide bone in a more curvilinear manner and achieve natural contour. Distraction was initiated on postoperative day 7 at the rate of 1 mm/d for 20-mm gain. At the 9-year follow-up, the patient showed improved head shape and intellectual status.

Predicting calvarial growth in normal and craniosynostotic mice using a computational approach

During postnatal calvarial growth the brain grows gradually and the overlying bones and sutures accommodate that growth until the later juvenile stages. The whole process is coordinated through a complex series of biological, chemical and perhaps mechanical signals between various elements of the craniofacial system. The aim of this study was to investigate to what extent a computational model can accurately predict the calvarial growth in wild-type (WT) and mutant type (MT) Fgfr2C342Y/+ mice displaying bicoronal suture fusion. A series of morphological studies were carried out to quantify the calvarial growth at P3, P10 and P20 in both mouse types. MicroCT images of a P3 specimen were used to develop a finite element model of skull growth to predict the calvarial shape of WT and MT mice at P10. Sensitivity tests were performed and the results compared with ex vivo P10 data. Although the models were sensitive to the choice of input parameters, they predicted the overall skull growth in the WT and MT mice. The models also captured the difference between the ex vivoWT and MT mice. This modelling approach has the potential to be translated to human skull growth and to enhance our understanding of the different reconstruction methods used to manage clinically the different forms of craniosynostosis, and in the long term possibly reduce the number of re-operations in children displaying this condition and thereby enhance their quality of life.

Single suture craniosynostosis: Identification of rare variants in genes associated with syndromic forms

We report RNA-Sequencing results on a cohort of patients with single suture craniosynostosis and demonstrate significant enrichment of heterozygous, rare, and damaging variants among key craniosynostosis-related genes. Genetic burden analysis identified a significant increase in damaging variants in ATR, EFNA4, ERF, MEGF8, SCARF2, and TGFBR2. Of 391 participants, 15% were found to have damaging and potentially causal variants in 29 genes. We observed transmission in 96% of the affected individuals, and thus penetrance, epigenetics, and oligogenic factors need to be considered when recommending genetic testing in patients with nonsyndromic craniosynostosis.