Metopic Ridge and Asymmetric Brachycephaly: Risk Assessment for Craniosynostosis
A metopic ridge alone does not indicate craniosynostosis and does not require surgical intervention or advanced imaging in the absence of other clinical features of trigonocephaly. 1
Clinical Distinction: Metopic Ridge vs. Metopic Craniosynostosis
The presence of a palpable metopic ridge is a common parental concern but must be distinguished from true metopic craniosynostosis (trigonocephaly). 1
Key Diagnostic Features
Metopic ridge WITHOUT craniosynostosis presents with:
- Isolated midline frontal ridge palpable on examination 1
- Normal fronto-orbital anatomy (no trigonocephalic deformity) 1
- Absence of hypotelorism (close-set eyes) 2, 3
- Absence of temporal narrowing 2
- Absence of recessed lateral orbital rims 3
True metopic craniosynostosis presents with:
- Triangular, keel-shaped forehead (trigonocephaly) 4, 3
- Hypotelorism (narrow-set eyes) 4, 3
- Bitemporal pinching/narrowing 2, 3
- Recessed lateral orbital rims 3
- Pronounced midline forehead ridge 2
Diagnostic Approach
Clinical examination is sufficient for diagnosis in most cases and should be prioritized over imaging. 5
Physical Examination Priorities
- Palpate fontanelles and sutures 4
- Measure head circumference 5
- Assess for trigonocephalic features: forehead shape, orbital spacing, temporal width 4, 3
- Evaluate facial skeletal development 4
Imaging Recommendations
- Ultrasound is often sufficient for suspected cranial suture anomalies when clinical examination is equivocal 5
- Advanced imaging (CT/MRI) should be reserved for equivocal clinical examinations or confirmed craniosynostosis requiring surgical planning 5
- Routine X-rays are NOT indicated for fontanelle abnormalities 5
Clinical Pitfall: Patent Suture with Clinical Features
A critical caveat: Infants can present with clinical manifestations of metopic craniosynostosis while still having a patent metopic suture on CT scan. 2 This emphasizes that imaging findings must be interpreted in the clinical context, and the presence of a patent suture does not automatically exclude the diagnosis if trigonocephalic features are present.
Regarding Asymmetric Brachycephaly
The provided evidence does not directly address asymmetric brachycephaly as a risk factor for craniosynostosis. However, the general principle remains: clinical examination distinguishes positional plagiocephaly/brachycephaly from true craniosynostosis. 6
- Positional brachycephaly (bilateral occipital flattening) is typically benign and responds to repositioning 6
- Imaging should only be pursued when clinical examination cannot definitively exclude craniosynostosis 6
Management Algorithm
For isolated metopic ridge:
- Clinical follow-up with photographs 1
- Parental reassurance 1
- No surgery indicated 1
- No routine imaging required 5, 1
For trigonocephalic features:
- Consider ultrasound if clinical examination equivocal 5
- CT/MRI for surgical planning if craniosynostosis confirmed 5
- Evaluate for increased intracranial pressure (headache, papilledema) 4
- Refer to craniofacial surgery 4, 3
Important note: Approximately 18% of children with metopic ridge have siblings with either metopic ridge or trigonocephaly, suggesting a familial component. 1 However, this does not change management for the isolated metopic ridge itself.