Available online 3 May 2024

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This investigation sought to ascertain whether orbital morphology could predict genuine metopic craniosynostosis (MCS).

Materials and Methods

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).

Results

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%).

Conclusion

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.

Section snippetsINTRODUCTION

Metopic craniosynostosis (MCS) describes the premature fusion of the metopic suture. With an incidence of about 1/2000 to 1/2500 (Betances et al., 2019), the incidence of MCS has been increasing over time, now representing around 28% of craniosynostosis presentations (van der Meulen et al., 2009; Beckett et al., 2012). As the field of craniofacial surgery begins to incorporate early methods of treatment that rely on the malleable infant skull (e.g., spring-assisted craniectomy, distraction

MATERIALS AND METHODS

After institutional review board approval (12-009276), a single-center, retrospective analysis was conducted. All three-dimensional computed tomograms (3D-CT) conducted from 2005 to 2022 were reviewed. Scans conducted over the age of 2 years were excluded, and the remainder were reviewed for radiographic evidence of trigonocephaly, hypotelorism and a fused metopic suture. The electronic medical records of these patients were then reviewed, and patients were categorized into two groups. Patients

RESULTS

A total of 103 patients met inclusion criteria (68 MCS, 35 MR), and 74 control patients were identified. Overall, 64.4% of patients were male, with the MR group having the highest proportion of male patients (77.1%), while controls had the lowest (55.4%), although this difference was not significant (p=0.067). Mean age at imaging was 0.67±0.52 years, and MCS patients underwent surgical correction of the cranium at a mean age of 0.84±0.31 years. MR patients were on average 4 months older than

DISCUSSION

Metopic craniosynostosis results in specific fronto-orbital dysmorphology that includes trigonocephaly, bitemporal constriction, and hypotelorism. In this study, orbital measurements associated with MCS were identified, most notably a narrowed SNS angle, which correlates with prior reports of the “teardrop shaped orbits” in MCS (van der Meulen, 2012; Ezaldein et al., 2014). All orbital changes were found to correlate with severity of trigonocephaly, as measured by IFA, highlighting the effects

CONCLUSION

Orbital measurements correlate with the severity of trigonocephaly in patients with metopic craniosynostosis—with the observed orbital dysmorphology more pronounced superomedially—correlating with the ability of the SNS angle to be a strong predictor of an MCS diagnosis. An SNS angle of greater than 130° yields a less than 5% chance of MCS. This straightforward measurement can be reproduced within seconds using 3D-CT on any image viewing platform.

Uncited reference

Bas and Bas, 2021; Betances and Mendez, 2019; Elbanoby and Elbatawy, 2020; Enlow and Hans, 1996; Hosmer et al.,.

Declaration of Competing Interest

JAT is a co-founder of Ostiio, LLC. JWS has developed educational content for Synthes. All other authors have no financial conflicts of interest to disclose.

REFERENCES (25)ChandlerL. et al.Distinguishing craniomorphometric characteristics and severity in metopic synostosis patients

Int J Oral Maxillofac Surg

(2021)

EzaldeinH.H. et al.Three-dimensional orbital dysmorphology in metopic synostosis

J Plast Reconstr Aesthet Surg

(2014)

BasN.S. et al.Craniometric Measurements and Surgical Outcomes in Trigonocephaly Patients Who Underwent Surgical Treatment

Cureus

(2021)

BeckettJ.S. et al.Classification of trigonocephaly in metopic synostosis

Plast Reconstr Surg

(2012)

BeirigerJ.W. et al.An Image-Based, Deep-Phenotyping Analysis Toolset and Online Clinician Interface for Metopic Craniosynostosis

Plast Reconstr Surg

(2023)

Betances EM, Mendez MD: Craniosynostosis....BirgfeldC.B. et al.Practical Computed Tomography Scan Findings for Distinguishing Metopic Craniosynostosis from Metopic Ridging

Plast Reconstr Surg Glob Open

(2019)

BlumJ.D. et al.Machine Learning in Metopic Craniosynostosis: Does Phenotypic Severity Predict Long-Term Esthetic Outcome?

J Craniofac Surg

(2023)

ElbanobyT.M. et al.One-Piece FO Distraction With Midline Splitting But Without Bandeau for Metopic Craniosynostosis Craniometric, Volumetric, and Morphologic Evaluation

Ann Plast Surg

(2020)

EnlowD.H. et al.Essentials of facial growth

American Journal of Orthodontics and Dentofacial Orthopedics

(1996)

FarberS.J. et al.Anthropometric Outcome Measures in Patients With Metopic Craniosynostosis

J Craniofac Surg

(2017)

FawzyH.H. et al.One-Piece Fronto-orbital Distraction With Midline Splitting But Without Bandeau for Metopic Craniosynostosis: Craniometric, Volumetric, and Morphologic Evaluation

Ann Plast Surg

(2019)

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© 2024 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.