How do you differentiate between craniosynostosis and positional plagiocephaly in an infant?

Distinguishing Craniosynostosis from Positional Plagiocephaly

Clinical examination alone is sufficient to differentiate craniosynostosis from positional plagiocephaly in the vast majority of cases, and imaging should be reserved only for equivocal clinical findings. 1, 2

Key Clinical Examination Findings

View the Infant's Head from Above (Bird's Eye View)

This single maneuver is the most critical distinguishing feature 3:

For Lambdoid Craniosynostosis:

• Posterior bossing appears in the parietal area contralateral to the flat side 3, 4
• The ear is displaced posteriorly toward the fused suture 3, 4
• A palpable ridge may be present along the fused suture 4

For Positional Plagiocephaly:

• Frontal bossing appears ipsilateral to the flat side 3, 4
• The ear is displaced anteriorly on the same side as the flattening 3, 4
• No palpable ridge along the suture 4
• The skull deformity is typically parallelogram-shaped when viewed from above 5, 4

Additional Distinguishing Features

Positional plagiocephaly characteristics:

• History of preferential head positioning or torticollis 5, 6
• Often associated with first birth, assisted labor, multiple pregnancy, or prematurity 5
• Improves with repositioning efforts 1, 5
• Bilateral occipital flattening (brachycephaly) is typically benign 7

Craniosynostosis red flags:

• Palpable ridging along suture lines 3, 4
• Progressive deformity despite repositioning 3
• Signs of increased intracranial pressure (papilledema on fundoscopic exam) 7
• Developmental delays 7
• Syndromic features requiring referral to specialized craniofacial centers 7

Imaging Strategy

When imaging is NOT needed:

• Clinical examination by an experienced provider clearly indicates positional plagiocephaly 1, 2
• The diagnosis can be established in 97% of cases through clinical examination alone 8

When imaging IS appropriate:

• Clinical examination is equivocal and cannot definitively exclude craniosynostosis 1, 7

Imaging hierarchy when needed:

• First-line: Skull x-rays or ultrasound of the suspect suture 1, 9
• Ultrasound can effectively assess suture patency in infants and avoids radiation 9, 8, 4
• Second-line: CT scan only if x-rays or ultrasound are non-diagnostic 1, 9
• Never routine: CT scanning should not be used routinely due to radiation risks and cancer risk in developing children 1, 9, 8
• No role: MRI plays no role in diagnosing craniosynostosis itself 1, 9

Critical Pitfalls to Avoid

• Do not order CT scans as a first-line diagnostic tool – this exposes infants to unnecessary radiation when clinical examination is sufficient 2, 9, 8
• Do not assume all plagiocephaly is positional – craniosynostosis requires surgical correction and missing this diagnosis has significant morbidity implications 1, 2
• Do not miss syndromic craniosynostosis – these cases require referral to nationally designated craniofacial centers 7
• Do not skip fundoscopic examination – papilledema indicating increased intracranial pressure is a critical finding requiring urgent intervention 7

Referral Pathway

Refer to pediatric plastic surgery or pediatric neurosurgery when:

• Craniosynostosis is suspected or confirmed clinically 2, 7
• Clinical examination is equivocal and specialist evaluation is needed 2
• Syndromic features are present 7
• Signs of increased intracranial pressure are detected 7

The specialist will:

• Definitively distinguish the two conditions through expert clinical examination 2
• Order imaging only if their clinical examination remains equivocal 2
• Determine appropriate treatment (repositioning, physical therapy, helmet therapy, or surgery) 1, 2