Craniosynostosis & Positional Plagiocephaly

What is positional plagiocephaly and what is craniosynostosis?

Distinct conditions that may appear similar externally—accurate differentiation is essential.

Positional plagiocephaly (PP) is a shape deformity of the infant skull caused by external pressure on a soft, malleable skull—most commonly when an infant rests for prolonged periods on the same side. Cranial sutures remain open.

Craniosynostosis is the premature fusion of one or more cranial sutures. This restricts skull growth in specific directions and produces characteristic cranial deformities. It may be:

• Nonsyndromic (isolated)—involving only the skull, typically a single suture (sagittal, metopic, coronal, or lambdoid).
• Syndromic—part of a broader genetic syndrome (Apert, Crouzon, Pfeiffer, Saethre–Chotzen, Carpenter, etc.) with multiple suture involvement, craniofacial anomalies, midface hypoplasia, and often limb or organ abnormalities.

Correctly distinguishing positional plagiocephaly from craniosynostosis is critical: the former is primarily managed conservatively, while the latter often requires cranial reconstructive surgery.

How common are they and at what ages do they appear?

Positional plagiocephaly is common and typically benign; craniosynostosis is far less frequent but clinically significant.

The prevalence of position-related plagiocephaly has increased substantially following the “Back to Sleep” campaign to prevent sudden infant death syndrome. It is estimated to affect up to 20–40% of infants within the first year of life, peaking around 4–6 months.

Nonsyndromic craniosynostosis occurs in approximately 1 in 2,000–2,500 newborns. The most common form is sagittal (scaphocephaly/dolichocephaly), followed by coronal (anterior plagiocephaly), metopic (trigonocephaly), and less commonly lambdoid.

Syndromic forms are even rarer but require specialized multidisciplinary care and coordinated interventions across childhood.

How do they develop—what is the pathophysiology?

Positional plagiocephaly is driven by external pressure, whereas craniosynostosis results from premature suture fusion.

Positional plagiocephaly: external pressure on a malleable skull

In positional plagiocephaly, cranial sutures are normal, but the skull is subjected to localized pressure, either in utero (multiple gestation, limited intrauterine space, breech presentation) or after birth (fixed sleep position, head preference, torticollis). Continuous pressure at a single site leads to a parallelogram-shaped skull with compensatory prominence in other regions.

Nonsyndromic craniosynostosis: premature suture fusion

In primary craniosynostosis, a single cranial suture fuses prematurely, often in utero. Pathogenesis appears to involve interactions between the dura mater and local osteoblasts at the fusion site, with increased cellular proliferation and heightened responsiveness to growth factors. In most nonsyndromic cases, no specific genetic mutation is identified.

Secondary craniosynostosis may occur in conditions such as rickets, hypophosphatemia, endocrine disorders, hematologic disease, or hydrocephalus following excessive CSF diversion.

Syndromic craniosynostosis: genetic mutations

Syndromic forms frequently involve mutations in fibroblast growth factor receptor genes (FGFR2, FGFR3) or other genes (e.g., TWIST, RAB23), disrupting normal suture ossification and producing characteristic clinical syndromes (Apert, Crouzon, Pfeiffer, Saethre–Chotzen, Carpenter, among others).

What are the typical signs and symptoms?

Parents often notice cranial asymmetry first; the specialist’s role is to determine which cases require observation and which warrant surgery.

Positional plagiocephaly

• From a vertex view, the head has a parallelogram shape: ipsilateral occipital flattening with compensatory frontal prominence.
• The ipsilateral ear may appear slightly anteriorly displaced.
• Torticollis is common; the infant may preferentially turn the head to one side.
• No signs of raised intracranial pressure or neurological deficit.

Nonsyndromic craniosynostosis

• Sagittal—elongated skull (scaphocephaly/dolichocephaly), frontal and occipital bossing, palpable bony ridge over the suture.
• Coronal—asymmetric forehead (anterior plagiocephaly), orbital elevation, ear displacement, “harlequin eye” on imaging.
• Metopic—triangular forehead (trigonocephaly), narrow frontal region and hypotelorism.
• Lambdoid—true posterior craniosynostosis with rhomboid shape, occipital flattening, posterior displacement of the ear and mastoid.

Syndromic forms

• involvement of multiple sutures, often with microcephaly,
• marked midface hypoplasia, proptosis, narrow palpebral fissures,
• possible congenital limb anomalies (syndactyly, broad digits), cardiac or other systemic abnormalities,
• symptoms of sleep apnea, elevated intracranial pressure, and visual or auditory impairment.

Any progressive cranial asymmetry, particularly if present from birth or associated with dysmorphic features, should be evaluated by a pediatric neurosurgeon/craniofacial team.

How is the diagnosis made and what tests are required?

An experienced clinical examination is often sufficient; imaging is used selectively.

Initial assessment includes:

• Comprehensive clinical examination—inspection from vertex, lateral, and frontal views; palpation of sutures and fontanelles; head circumference measurement.
• Assessment for torticollis and associated facial or limb anomalies (in syndromic craniosynostosis).

In most cases of simple positional plagiocephaly, diagnosis is clinical and CT is unnecessary. If true craniosynostosis is suspected, the following may be required:

• Skull radiographs in targeted views or CT with three-dimensional reconstructions to confirm suture fusion.
• In syndromic forms, brain MRI and detailed evaluation for hydrocephalus, posterior fossa anomalies, or Chiari malformation.
• Genetic testing when a specific syndrome is suspected.

Preoperative planning may also include ophthalmologic, otolaryngologic, and respiratory assessments, particularly in syndromic cases with possible obstructive sleep apnea or visual impairment.

What are the potential impacts and risks?

In positional plagiocephaly concerns are primarily aesthetic; in craniosynostosis there is an additional, albeit limited, risk of elevated intracranial pressure and psychosocial consequences.

Positional plagiocephaly

• No association with increased morbidity or restricted brain development.
• However, if untreated, it may result in significant cosmetic asymmetry with potential long-term psychosocial impact.

Nonsyndromic craniosynostosis

• In most single-suture forms, the risk of significant intracranial hypertension is relatively low (approximately 15–20%).
• Cosmetic deformities can be pronounced and may worsen with growth if not corrected early.

Syndromic craniosynostosis

• Higher risk of elevated intracranial pressure, visual and auditory impairment, obstructive sleep apnea, and neurodevelopmental challenges.
• Multiple surgical procedures are often required (cranial vault, midface, orthognathic) through adolescence.

When is conservative management and helmet therapy sufficient?

For benign positional plagiocephaly, prevention, positional modification, and in selected cases, cranial orthoses are the mainstays of treatment.

In positional plagiocephaly, key principles include:

• Prevention from the first weeks of life: alternating sleep position, supervised prone (“tummy time”) several times daily, avoiding prolonged time in car seats or bouncers.
• Active repositioning once asymmetry is noted: positioning to offload the flattened side and using visual or auditory stimuli toward the unaffected side.
• Physiotherapy/torticollis exercises when neck mobility is limited.

A cranial helmet may be considered:

• in cases of severe asymmetry unresponsive to repositioning,
• in infants approximately 4–6 months of age, when the skull remains highly malleable.

The helmet guides skull growth by allowing expansion in flattened areas. It requires proper fitting, regular adjustments, and consistent use. Potential drawbacks include skin irritation, pressure points, family burden, and cost—hence it is not recommended for mild cases that improve with conservative measures.

Surgery has no role in uncomplicated positional plagiocephaly.

When is surgery indicated in nonsyndromic craniosynostosis?

The goals are to restore adequate intracranial volume and achieve cranial symmetry with the least possible burden for the infant.

Indications for surgery in nonsyndromic craniosynostosis include:

• clear suture fusion with characteristic deformity,
• suspected or documented elevated intracranial pressure,
• significant cosmetic deformity expected to worsen with growth.

Age is pivotal in determining the operative approach:

• 0–6 months: minimally invasive techniques are preferred, including endoscopic or limited suturectomy followed by postoperative molding helmet therapy.
• 4–12 months: in more advanced or complex cases, open cranial vault remodeling is performed (e.g., fronto-orbital advancement, bandeau, biparietal craniotomy with barrel staving).

Minimally invasive approaches are associated with reduced blood loss, shorter hospitalization, and faster recovery, but require very early diagnosis and strict adherence to postoperative helmet therapy.

What applies to syndromic craniosynostosis?

These are complex conditions requiring specialized centers and long-term, staged surgical planning.

Syndromic craniosynostoses (Apert, Crouzon, Pfeiffer, Saethre–Chotzen, Carpenter, among others) are characterized by:

• multisuture fusion and restricted intracranial volume,
• midface hypoplasia, proptosis, cleft palate,
• possible anomalies of the hands/feet, heart, and airway.

Management is coordinated by a craniofacial team (pediatric neurosurgeon, craniofacial/plastic surgeon, ENT, pediatric cardiologist, geneticist, ophthalmologist, speech therapist) and includes:

• Early cranial surgery (approximately 6–9 months) to increase intracranial volume and improve head shape.
• Potential staged procedures of the cranial vault and midface (Le Fort III, monobloc) later in childhood/adolescence.

Reoperation rates are significantly higher than in nonsyndromic disease, making ongoing surveillance essential.

What are the possible complications and the postoperative course?

Procedures are extensive but generally safe in specialized centers, with low rates of serious complications.

Potential complications include:

• bleeding that may require transfusion,
• wound or bone infection (rare),
• CSF leak, seroma, or leptomeningeal cysts,
• transient hyponatremia, eyelid/facial edema,
• need for reoperation at a rate dependent on deformity type and severity.

Most infants require hospitalization for several days, with close monitoring initially in the ICU/step-down unit, followed by ward care until hemodynamics, pain control, and feeding are stable.

What is the prognosis and how is long-term follow-up conducted?

In most nonsyndromic cases, aesthetic outcomes are excellent and development is normal, provided timely and appropriate treatment.

For positional plagiocephaly, prognosis is excellent. With appropriate prevention, repositioning, and when indicated helmet therapy, most children achieve a near-symmetric skull by 1–2 years of age.

In nonsyndromic craniosynostosis, cosmetic outcomes are typically very good with both minimally invasive and open techniques, and reoperation rates are low. Neurodevelopmental impact remains under study, but most children, particularly with single-suture disease, demonstrate normal academic performance.

In syndromic forms, prognosis depends on the underlying syndrome, associated anomalies, effective control of intracranial pressure, and timely management of airway and ophthalmologic issues. Long-term follow-up includes regular assessment of:

• head circumference and growth,
• vision, hearing, and dental-occlusal development,
• sleep and respiration,
• cognitive and psychosocial development.