Metopic Ridge Research Articles

Geometric Morphometric Study on Distinguishing Metopic Craniosynostosis from Metopic Ridging.

Craniosynostosis, a common congenital anomaly, results from premature fusion of the cranial sutures. One of the forms of craniosynostosis is premature fusion of the metopic suture, referred to as trigonocephaly, but the diagnosis of metopic suture synostosis remains controversial. The purpose of this study was to clarify, using geometric morphometric analysis, if a metopic ridge alone observed in cases of mild trigonocephaly represents a pathological phenomenon. Three different cranial morphologies were compared among patients up to 2 years old who were categorized into the true group, the mild group, and the normal group, based on the presence or absence of specific symptoms, history of cranioplasty for trigonocephaly, or lack of any abnormality on computed tomography. Using the obtained computed tomography images, 235 anatomical landmarks and semi-landmarks were plotted on the entire cranial surface for analysis of neurocranial morphology, and the cranial shapes represented by landmarks were analyzed using geometric morphometrics. Principal components of shape variations among specimens were then computed, based on the variance-covariance matrix of the Procrustes residuals of all specimens, and statistically analyzed. The principal component analyses of the variations in endocranial shape, frontal bone shape, and occipital bone shape did not show any significant differences in cranial morphology between mild trigonocephaly and normal skulls; however, true trigonocephaly was found to differ significantly from mild trigonocephaly and normal skulls. These findings suggest that in assessments of cranial morphology, the presence of a ridge alone cannot be diagnosed as fundamentally pathological, and may represent normal morphology.

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

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. 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. 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. 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.

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.

What can a morphometric study of unoperated children teach us about the natural history of metopic synostosis?

Outcomes of surgical repair of trigonocephaly are well reported in the literature, but there is a paucity of information on the natural history of unoperated children. The authors evaluated a group of unoperated children with metopic synostosis to describe the natural change in head shape over time. A database was screened for scans of children with unoperated trigonocephaly (2010-2021). Multisuture cases and those with a metopic ridge were excluded. Three-dimensional surface scans (3D stereophotogrammetry/CT) were used for morphological analysis. Nine previously published parameters were used: frontal angle (FA30°), anteroposterior (AP) volume ratio (APVR), AP area ratio (APAR), AP width ratios 1 and 2 (APWR1 and APWR2), and 4 AP diagonal ratios (30° right APDR [rAPDR30], 30° left APDR [lAPDR30], 60° right APDR [rAPDR60], and 60° left APDR [lAPDR60]). Ninety-seven scans were identified from a cohort of 316 patients with a single metopic suture, in which the male-to-female ratio was 2.7:1. Ages at the time of the scan ranged from 9 days to 11 years and were stratified into 4 groups: group 1, < 6 months; group 2, 6-12 months; group 3, 1-3 years; and group 4, > 3 years. Significant improvements were detected in 5 parameters (APVR, APAR, APWR1, rAPDR30, and lAPDR30) over time, whereas no significant differences were found in FA30, APWR2, rAPDR60, and lAPDR60 between age groups. Forehead shape (surface area and volume), as well as narrowing and anterolateral contour at the frontal points, differed significantly over time without surgery. However, forehead angulation, narrowing, and anterolateral contour at temporal points did not show significant differences. This knowledge will aid in surgical and parental decision-making.

Natural history of mild trigonocephalic deformities.

Ridging along the metopic suture line can be a common cause of concern for parents and has been theorized to represent a mild form of trigonocephaly, a cranial deformity associated with risks of negative cosmetic outcomes, if not surgically corrected. Yet the literature contains sparse reports of long-term cosmetic results or expectations for infants with isolated metopic ridging compared with those with severe trigonocephaly, or even what objective metrics discriminate isolated metopic ridging from severe trigonocephaly. Therefore, the authors' goals for this study were to 1) quantify the degree of frontal deformity among patients with metopic ridge, metopic craniosynostosis, and normocephalic head shapes; and 2) document the natural history of frontal deformities in isolated metopic ridge patients in the 1st year of life. This was a retrospective cohort study of patients with normocephalic head shapes, metopic ridges, and metopic craniosynostoses who presented at < 1 year of age to the Connecticut Children's neurosurgery clinic from January 2019 to December 2021. Data were collected regarding demographics and photograph-based craniometrics. A total of 212 normocephalic, 34 metopic ridge, and 29 metopic craniosynostosis patients were included. Both the normocephalic and metopic ridge groups had a significantly higher anterior arc angle (AAA) value compared with the metopic craniosynostosis group (p < 0.0001). The AAA did not differ significantly among normocephalic patients and those with ridging. Over the course of 1 year of follow-up, patients with metopic ridging demonstrated a slight decrease in AAA values, but overall remained within the same range as normocephalic patients. Photograph-based craniometrics suggest that metopic ridge patients with frontal bone angulations > 2.2 radians have a mild degree of frontal constriction that does not significantly worsen over the 1st year of life.

Metopic ridge presenting to pediatric dermatology and vascular anomalies clinics.

Metopic ridge (MeR) is a midline osseous forehead prominence resulting from physiologic closure of the underlying metopic suture. This mass-like ridge can be mistaken for serious conditions such as a craniosynostosis or vascular anomaly, prompting concern and workup. We reviewed patients presenting for a forehead mass to Vascular Anomalies and Dermatology clinics and diagnosed with MeR to increase familiarity with this finding and to encourage MeR in the differential diagnosis of pediatric midline forehead masses.

Reply: Cerebral Blood Flow of the Frontal Lobe in Untreated Children with Trigonocephaly versus Healthy Controls: An Arterial Spin Labeling Study.

We have read with great interest the letter from Long et al. regarding our article.1 Their letter stated two methodological concerns to which we will respond. The first concern is that objective criteria are missing for true trigonocephaly or benign metopic ridge. We only included patients with moderate to severe trigonocephaly according to the definitions of Birgfeld et al.2 In their article, Birgfeld et al. provide a phenotypical distinction between benign metopic ridge and metopic synostosis, as well as illustrative photographs with corresponding computed tomographic imaging.2 Cho et al.3 and Anolik et al.4 described computed tomographic measures to assess severity of metopic synostosis. In both studies, the cut-off point to determine surgical indication remained subjective, and poor consensus for the intermediate presentation of metopic craniosynostosis was found. In addition, Sisti et al.5 recently reviewed all literature in PubMed on trigonocephaly, relating to 15 anthropometric cranial measurements for surgical indications. They found that most articles have a lack of diagnostic criteria for trigonocephaly. At our center, the decision for surgery is made through shared decision-making with parents. In 2021, this resulted in surgery for 14 patients (moderate or severe presentation) and a conservative treatment for 40 patients (18 with mild presentation and 22 with moderate or severe presentation). The second concern Long et al. raise is the potential blunting effect of sevoflurane on cerebral blood flow (CBF). If there is a blunting effect, a similar effect on both patients and controls is expected. In our previous arterial spin labeling study in patients with syndromic craniosynostosis using the same sedation protocol, we found a difference between the groups.6 This suggests that the normal findings in patients with trigonocephaly reflect normal CBF. Very few studies have investigated the influence of anesthesia on arterial spin labeling CBF in the pediatric population. Carsin-Vu et al.7 included 84 subjects ranging in age from 6 months to 15 years and showed no significant CBF changes with sevoflurane in comparison to general anesthesia. Kaisti et al.8 showed in eight healthy male patients (age range, 20 to 26 years) that sevoflurane reduced regional CBF less than propofol did. Without sedation, scanning of one sequence is possible, because of the limited timeframe. However, more sequences, as in our protocol, requires a longer time period. Without sedation, motion artifacts would make it impossible to analyze. Finally, Long et al. mention that cerebral perfusion is a limited measure of neurodevelopment and that functional magnetic resonance imaging (MRI) studies in patients with scaphocephaly have shown a difference in functional brain connectivity compared with controls. However, there is still a lot unknown about the optimal method of scanning, reproducibility, and interpretation of functional MRI results. Finding a difference in connectivity in functional MRI studies would be at the same level of evidence as the arterial spin labeling brain MRI study.9 To conclude, our study further supports our hypothesis that surgery for trigonocephaly is rarely indicated functionally. Parents should be informed about the unknown added value of surgery regarding raised intracranial pressure and brain perfusion. Comparative research on outcome of conservative versus surgical treatment of moderate to severe trigonocephaly is needed to establish clinical guidelines. DISCLOSURE The authors have no financial interest to declare in relation to the content of this communication. Catherine A. de Planque, MDDepartment of Plastic, Reconstructive Surgery, and Hand SurgeryErasmus MC-Sophia Children’s HospitalUniversity Medical Center RotterdamRotterdam, The Netherlands Jan Petr, PhDHelmholtz-Zentrum Dresden-RossendorfInstitute of Radiopharmaceutical Cancer ResearchDresden, Germany Linda Gaillard, MDDepartment of Plastic, Reconstructive Surgery, and Hand SurgeryErasmus MC-Sophia Children’s HospitalUniversity Medical Center RotterdamRotterdam, The Netherlands Henk J. M. M. Mutsaerts, MD, PhDVrije Universiteit AmsterdamAmsterdam NeuroscienceAmsterdam, The Netherlands Marie-Lise C. van Veelen, MD, PhDDepartment of Neurosurgery Sarah L. Versnel, MD, PhDDepartment of Plastic, Reconstructive Surgery, and Hand Surgery Marjolein H. G. Dremmen, MDDepartment of Radiology and Nuclear Medicine Irene M. J. Mathijssen, MD, PhD, MBA-HDepartment of Plastic, Reconstructive Surgery, and Hand SurgeryErasmus MC-Sophia Children’s HospitalUniversity Medical Center RotterdamRotterdam, The Netherlands

Maternal Levothyroxine Treatment as an Etiologic Factor in the Development of Infantile Craniosynostosis

AbstractCraniosynostosis (CS) is a condition characterized by premature fusion of one or more calvarial sutures. Numerous studies have demonstrated a correlation between CS and maternal hypothyroidism (MH), but research into this relationship has been scarce. A six-day-old male patient presented for initial neurosurgical consultation with trigonocephaly and prominent metopic ridging. A CT scan of the head confirmed the diagnosis of metopic CS, and it was revealed during the examination that the mother suffered from hypothyroidism during her pregnancy. Two theories provide a potential etiologic basis for the development of CS in infants born to hypothyroid mothers treated with levothyroxine. It is possible that the transplacental delivery of levothyroxine results in fetal thyrotoxicosis. Alternatively, intermittent periods of maternal hypothyroxinemia may encourage fetal thyroid hyperactivity to compensate for insufficient maternal thyroid hormones. Regardless, both theories must be formally investigated in order to elucidate the true association between CS and MH.

Preterm Infant with Craniofacial Dysmorphic Features and Posture.

Preterm Infant with Craniofacial Dysmorphic Features and Posture.

Outcomes of a virtual craniofacial clinic for assessing plagiocephaly during the COVID-19 pandemic.

The aim of this study was to carry out a quantitative analysis of a virtual craniofacial clinic during the COVID-19 pandemic. The charts of 90 patients from a single institution were reviewed. Of these patients, 45 visited the virtual clinic during the COVID-19 pandemic. The other 45 patients visited the clinic in the 3 months prior to COVID-19. Demographics including the mean age at the visit, chief complaint, visit diagnosis, appointment duration, helmet usage, accuracy of the diagnosis, need for a CT scan, and the need for a follow-up appointment were assessed. Diagnostic accuracy, the frequency of follow-up appointments, and patient satisfaction (via survey), as well as additional associated factors, were analyzed to determine the efficacy and satisfaction associated with the virtual clinic approach. The mean patient age at time of the visit was 5.6 and 7.3 months (p = 0.244), and the mean time from referral to appointment was 19.2 and 19 days (p = 0.934), in the in-person and virtual cohorts, respectively. There was no significant difference in the variety of chief complaints between the in-person and virtual visits, with 97.8% and 93.3% of patients' parents reporting abnormal head shape, respectively, and the remainder reporting more infrequent complaints (p = 0.435). The visit diagnosis was plagiocephaly in 93.3% of the in-person cohort and 80.0% of the virtual cohort (p = 0.118). The final diagnosis exhibited a similar pattern, with 95.6% of the in-person cohort and 88.9% of the virtual cohort observed as positional plagiocephaly; the remaining diagnoses were more infrequent (p = 0.434). The most common alternative diagnosis in the virtual visit cohort was a metopic ridge (8.4%). In the in-person visit cohort, the most common alternative diagnosis was equally a benign enlargement of the subarachnoid space in infancy, scalp mass, and skull lesion (2.2% each). None of the patients in either cohort were diagnosed with synostosis. Eighty percent of the in-person visits were 15 to 30 minutes in duration, with the remaining 20% being 31 minutes or longer; virtual visits were all 30 minutes or less, with 95.6% being 15 to 30 minutes (p = 0.002). Helmets were prescribed for 2 patients in the in-person cohort and no patients in the virtual cohort (p = 0.494). Alterations in diagnosis were made in 2.2% of in-person visits and 6.7% of virtual visits (p = 0.616). Follow-up was required in 15.6% of the in-person visits and 31.1% of the virtual visits (p = 0.134). CT was only utilized twice, once in the in-person visit cohort and once in the virtual visit cohort. Virtual clinic encounters resulted in comparable diagnostic accuracy. The trend toward frequent follow-up assessments and changes in the final diagnosis in the virtual clinic cohort has indicated a level of diagnostic uncertainty via the virtual interface, which required in-person assessment for confirmation. This finding did not contribute toward diagnostic inaccuracy with respect to missed synostosis. The study results have indicated that telemedicine can be an effective modality in assessing craniofacial pathology.

Metopic Ridge: True Craniosynostosis or Result of Positional Plagiocephaly?

Jordan, Ashley MD; DeSantis, Joseph G. MD, FACS; Kauffman, Christian A. MD Author Information

Outcomes of Surgical Management of Metopic Synostosis : A Retrospective Study of 18 Cases

ObjectiveTo describe the surgical management and postoperative outcomes in infants with metopic synostosis. MethodsWe conducted a 5 years retrospective chart review of patients who underwent surgical correction of metopic synostosis at two university hospitals in Egypt during the period between June 2014 and June 2019. The study is conducted to 18 children. The type of surgical procedures and postoperative outcomes were assessed in all patients. ResultsFive cases (27.8%) underwent endoscopic-assisted suturectomy, 10 cases (55.6%) underwent craniofacial reconstruction, and three cases (16.6%) underwent open burring of the metopic ridge. Fifteen patients underwent one surgery and three patients (16.6%) who need second operation. Ten patients (55.6%) had class I Whitaker classification. ConclusionRegardless of type of surgery, the outcomes of surgical correction of metopic synostosis are excellent with only a few patients require revision or develop major complications.

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

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. Retrospective cohort study. Tertiary academically affiliated children's medical center. 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). 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. Bitemporal width to biparietal width (ratio). 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. 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.

Part 1: Surgical Correction in 231 Trigonocephaly Patients - The Alder Hey Experience.

Isolated metopic synostosis presents with a range of severity, from a palpable ridge as the sole presenting feature to a constellation of features resulting in trigonocephaly. At our unit, patients on the moderate to severe end of the phenotypic spectrum of trigonocephaly are offered fronto-orbital advancement and remodeling. The authors present our series of trigonocephaly patients who have undergone surgical correction. From January 2000 to January 2020, the authors operated on 231 patients with trigonocephaly. The average age at surgery was 18 months, with an average follow-up of 77.4 months. Seventy-nine percent of patients had no comorbidity. Ten percent of patients sustained a dural tear with no long-term consequences. The total early complication rate was 12.1%. The most common early complications were wound infection and wound dehiscence at 7.4% and 3.9% respectively. The total reoperation rate was 6.5%. The introduction of infection prevention and control measures over the 2 decades at our unit reduced the reoperation rate to 1.1%. The most common late complication was temporal recession in 20.8% of patients, none of whom required aesthetic correction. The recurrence rate of a metopic ridge was 2.3% with no patients requiring further surgery. None of our patients required calvarial remodeling for raised intracranial pressure after the primary fronto-orbital advancement and remodeling. There were no life-threatening complications or mortalities in our cohort. The authors present recommendations which include an infection control care bundle, cessation of surgical drains, and practice adjustments to reduce risks of infection and risk of requiring further calvarial remodelling for raised intracranial pressure.

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

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. 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. 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). 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.

Clinical manifestations of 11 children with fronto-ocular syndrome (FOS): a case series

Fronto-ocular syndrome (FOS) is a rarely seen trigonocephaly syndrome in which metopic synostosis features are unique. This report presents six cases with FOS. Clinical manifestations mainly involve skull and facial findings. Nearly all patients have short/upslanted palpebral fissures, hypotelorism, narrow bifrontal area, philtrum anomalies, trigonocephaly, and metopic ridge. Epicanthal folds, hypoplastic supraorbital ridges, bulbous nasal tip, thin upper lip, mandible, and ear anomalies are also frequently observed in the patients. Extrafacial findings are variable such as cardiac, extremity anomalies, and skin findings. Mild developmental delay and learning disability have been presented in almost half of patients. Age-dependent and age-independent phenotypic differences between the patients have been detected. Furthermore, it is observed the individuals with reduced phenotypic expression even in the same family. FOS has been described in two families in the literature which consist of mother-daughter dual. Thereby, its inheritance pattern and clinical spectrum have not been clarified clearly. We present here eleven patients that five of them had previously reported. We aim was to give a more comprehensive description of the clinical findings of fronto-ocular syndrome and to reveal its inheritance pattern.

Orbito-facial dysmorphology in patients with different degrees of trigonocephaly severity: quantitative morpho-volumetric analysis in infants with non-syndromic metopic craniosynostosis

Craniofacial dysmorphology varies significantly along a wide spectrum of severity in metopic cranial synostosis (MCS). This study aimed to quantify craniofacial changes, in MCS, to investigate their relationships with the severity of trigonocephaly. By combining the metopic ridge and interfrontal angles, we identified three groups of trigonocephaly severity (mild group n.14, moderate group n.19, severe group n.18). We perform a quantitative analysis using high-resolution CT images evaluating (1) cranial fossae dimensions; (2) vault indices and ratios: interparietal/ intercoronal (IPD/ICD), interparietal/intertemporal (IPD/ITD), cephalic index, vertico-longitudinal index; (3) orbito-facial distances (midfacial depth, maxillary height, upper facial index, orbital distances, globe protrusions), maxilla and orbital volumes; (4) supratentorial (ICV) and infratentorial (PCFV) cranial volumes and supratentorial (WBV) and infratentorial (PCFBV) brain volumes. In all groups, middle skull base lengths and upper midface index were increased. In moderate and severe groups: anterior hemifossa lengths were reduced, IPD/ICD and vertico-longitudinal index were changed; midfacial depth, anterior, mild, and lateral interorbital distances were reduced; globe protrusions were increased. The comparison between moderate and severe groups showed an increase of both globe protrusions and IPD/ICD. Among all groups, ICV and WBV were reduced in the severe group. This morpho-volumetric study provides new insights in understanding the craniofacial changes occurring in infants at different severity of trigonocephaly. The increase of globe protrusions and the reduction of supratentorial volumes found in the severe group reflect the severity of trigonocephaly; these findings might have a clinical and surgical relevance.

S8A-07 SESSION 8A: METOPIC SYNOSTOSIS TRIGONOCEPHALY, A SHIFT IN INDICATION FOR SURGERY

Introduction: Patients with metopic synostosis have a very small chance to develop raised intracranial pressure. In addition, there is no conclusive evidence yet that a surgical correction of trigonocephaly will improve neurocognitive outcome. Only for the most severe presentations of trigonocephaly, there is clear gain in aesthetic outcome. Therefore, the indication for surgery for metopic synostosis at our center shifted towards correction of only the severe clinical presentations in the past three years. The objective is to study the differences between the operated and non-operated group of trigonocephaly patients at our center. Methods: All patients referred to our center for trigonocephaly in the past three years were evaluated. In this presentation, physical parameters on which the operation indication was based are analysed, using photographs, CT and fundoscopy. Furthermore, the results of both the operated and non-operated trigonocephaly patients on the Bayley Scales of Infant and Toddler Development (a developmental test including a Cognitive, Language, and Motor Scale), taken around the age of two years, will be presented. Results: 218 patients were initially referred to our center for trigonocephaly in the period 2016–2018. Further follow-up after the first visit was not indicated in 128 patients (very mild presentation/ metopic ridge). Of the remaining 90 patients, at the first visit, 39 patients had an indication for follow-up without surgery (fundoscopy/ head circumference), and 26 patients got the indication for a fronto-orbital advancement, which they all received. Twenty-five patients had a reassessment at the age of 9 months; a natural improvement occurred in 20 patients, 3 patients were operated and 2 patients had an operation indication but surgery was refused by the parents. The most important clinical parameter for indication for surgery was the relation between the lateral parts of the forehead and the lateral orbital rims from bird eyes view. Fifteen patients of the operated group and 15 patients of the non-operated group received the developmental test. Conclusion: Natural improvement was observed, which advocates reassessment in a selected group. Short-term neurocognitive evaluation can be indicative for the future, but further longitudinal follow-up is necessary to determine whether there is a neurocognitive indication for operation or whether it is just an aesthetic procedure. This knowledge is important, in order to better involve parents in the shared decision making process of this possible high risk procedure.

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

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

S8A-13 SESSION 8A: METOPIC SYNOSTOSIS OPHTHALMOLOGIC FINDINGS IN CHILDREN WITH METOPIC SUTURE ABNORMALITIES

Introduction: Ophthalmic abnormalities in children with syndromic craniosynostosis have been reported, and referral to an ophthalmologist is recommended. We have previously reported children with isolated metopic craniosynostosis demonstrate an increased rate of amblyopia and its risk factors. It is known that there is a wide spectrum of metopic suture abnormalities ranging from ridge to severe trigonocephaly, and that metopic suture abnormalities can be seen with deformational plagiocephaly (DP) and/or brachycephaly (B). It is not clear if milder forms of metopic abnormalities need to be referred to an ophthalmologist. The aim of this study is to report the incidence of ophthalmic abnormalities in children with isolated metopic abnormalities ranging from those with mild trigonocephaly to severe and those in conjunction with DP and/or B. Methods: An IRB–approved, retrospective review was performed on 189 children under 2 years of age diagnosed with isolated metopic abnormalities from 2007–2017. 110 children diagnosed with metopic ridge to mild/moderate trigonocephaly and DP/B were evaluated by ophthalmology and included in the study. Patients were stratified into the following categories: DP (n=28), B (n=10), DP/B (n=39), mild/moderate trigonocephaly (n=16), or severe trigonocephaly (n=17). Records were reviewed for diagnoses of amblyopia, strabismus, and refractive errors. Patients with other suture involvement, syndromic diagnoses, and primary ocular disorders were excluded. Results: Of the 110 children, 66 (60%) had no abnormal ophthalmologic findings, 13 (11.8%) had strabismus, 13 (11.8%) had amblyopia, 28 (25.5%) had astigmatism, 14 (12.7%) had hyperopia, 5 (4.5%) had myopia, and 8 (7.3%) had anisometropia. The incidence of amblyopia in the general pediatric population is 1.5% to 1.8% (Multi-ethnic Pediatric Eye Disease, 2008; McKean-Cowdin, 2013); strabismus is 2.4% to 3.6% (McKean-Cowdin, 2013); and rates of 1.2% to 4% for myopia, 13.5% to 25.7% for hyperopia, and 6.3% to 8.3% for astigmatism (Wen et al., 2013). Conclusion: In our population, children with isolated metopic abnormalities, regardless of their associated head shape, demonstrate an increased rate of amblyopia and its risk factors, with the exception of hyperopia, than the general pediatric population. The increased rate of visual abnormalities places this population at higher risk for improper visual development. Those with isolated metopic abnormalities including minor trigonocephaly or deformational head shapes are often not referred to ophthalmology, leaving a large group with undiagnosed visual issues. Thus, prompt referral to an ophthalmologist could benefit this population, as early treatment leads to improved outcomes.