Introduction

Definition of plagiocephaly

Plagiocephaly is a condition present at birth in which a newborn baby’s head appears flattened at the back or sides. It often develops during pregnancy, though there has been an increase in cases of post-birth plagiocephaly. The flattening of the skull is thought to occur due to external pressure, as the bones of the skull have not yet fused in early infancy. Excess pressure can push these bones inward, creating a flattened appearance.¹ 

This article will provide an overview of plagiocephaly, including its different types, common symptoms and treatment options.

Types of plagiocephaly

Plagiocephaly can be categorised into several types, each with distinct diagnostic features:^2,3,7,8

Positional Plagiocephaly: The most common form, occurring in almost 50% of babies, positional plagiocephaly results in a flattened or misshapen spot on the baby’s head. This is typically caused by prolonged pressure on one side of the skull, often due to sleeping positions.

Brachycephaly: This type causes the back of the head to flatten, leading to a head shape that appears shorter and wider at the back. It often results from the baby spending extended time lying on their back, which is common in babies who sleep on their backs for safe sleep practices.

Scaphocephaly: More commonly found in premature infants, especially those who have spent time in the neonatal intensive care unit (NICU), scaphocephaly results in a long, narrow head shape. This condition can occur due to the baby’s position in the NICU or the restricted space in incubators.

Craniosynostosis: A rare form of plagiocephaly, craniosynostosis is caused by a congenital defect where the fibrous joints in the baby’s skull close prematurely, restricting normal skull growth and resulting in an abnormal head shape.

Causes of plagiocephaly

Plagiocephaly occurs when pressure on a baby’s soft skull causes it to flatten, often due to prolonged periods spent lying on the back or turning the head to one side.^1,2 Since a baby’s skull is not fully developed at birth, this pressure can shape the skull as the bones are not yet fused. Premature babies are more susceptible, as their skulls are less developed than those born at term. Additional risk factors include:²

• Pregnancy with multiples
• Use of forceps or vacuum extractors during delivery
• Low levels of physical activity
• Prolonged lack of tummy time (resting too much on the back)

Diagnosis of plagiocephaly

Plagiocephaly is diagnosed through a physical examination of the baby's head and skull shape.⁴ A diagonal caliper may be used to measure the diagonal lengths of the head. However, to ensure accuracy, doctors may order additional imaging scans like ultrasound, MRI, or CT scans, particularly if craniosynostosis is suspected. These scans help confirm the diagnosis and provide more information for determining the most appropriate treatment.

Treatment options

Cranial molding helmets

For noticeable flattening, cranial molding helmets can help correct head shape.^5,6 These helmets apply gentle pressure on the flattened areas, allowing the skull to grow in the right direction. Treatment typically lasts three months, and the helmet is comfortable for the baby. The soft inner shell and hard outer shell work together to provide the necessary support for healthy skull growth.^5,6

Positioning and tummy time

Increasing tummy time, alternating holding positions, and encouraging the baby to turn their head can prevent further flattening.⁷ For babies with stiff necks, physiotherapy may be recommended.

Surgical intervention

Surgical intervention is rarely required but may be necessary for severe cases, particularly in craniosynostosis, where the skull bones fuse prematurely. There are two main surgical options:^2,8

Traditional surgery

• Performed for severe craniosynostosis cases
• Involves a longer procedure and a hospital stay
• Requires significant recovery time

Minimally invasive surgery

• Most successful for infants under six months
• Fewer risks and complications, with only one or two small incisions
• A closed suture is removed to unlock the skull bones
• Does not require blood transfusions and lasts under an hour
• The baby stays overnight as a precaution but is free to leave the next day
• No swelling around the eyes
• Postoperative cranial molding helmets or custom springs are required to maintain proper head shape and promote growth

Cranial distraction (rare)

• Reserved for cases where most cranial sutures have closed
• Involves placing distractors inside the skull to gradually separate the bones
• Distraction occurs at a rate of 1mm per day, creating new bone
• A second surgery is required after about three months to remove the distractors

Craniosynostosis, a severe form of plagiocephaly, may necessitate surgery to unlock and reshape the skull.⁸ While traditional surgery is invasive, the minimally invasive procedure offers a quicker, safer option with a faster recovery period. Cranial distraction is a more complex and rare procedure used in very specific cases.

Prognosis

For most cases of plagiocephaly, the prognosis is positive. With proper repositioning techniques, such as increasing tummy time and using cranial molding helmets, the condition typically improves within a few months. The skull will usually return to a more normal shape as the baby grows and the bones continue to develop. If treated early, the risk of long-term effects is minimal, and the head shape should normalize without permanent alterations.

However, if plagiocephaly is left untreated, it may lead to lasting head shape abnormalities. In severe, untreated cases, the asymmetry in the skull could affect facial development or cause uneven growth patterns. That said, such severe cases are rare, and most infants recover with conservative management.

In the case of craniosynostosis, the prognosis depends on the timing and type of intervention. If diagnosed early, surgical treatments, whether traditional or minimally invasive, are generally successful in restoring normal skull shape. Without intervention, craniosynostosis can lead to significant developmental issues, including potential pressure on the brain, which may result in cognitive or developmental delays. Therefore, early diagnosis and appropriate surgical treatment are crucial for a favorable outcome.

Summary

• Plagiocephaly is the flattening of the head, with different types, including positional plagiocephaly (most common) and craniosynostosis (least common)
• Prevention focuses on reducing time spent lying on the back or on one side, as this is the largest contributing factor to flattening
• If flattening does not improve, consult a healthcare provider who may recommend:
  • Cranial molding helmets that apply pressure to protruding areas and reduce pressure on flat areas, promoting growth.
• Diagnosis is made by a physician in a clinic, using physical measurements of the skull and confirming with medical imaging
• Surgical intervention is unnecessary for most cases of plagiocephaly unless it is craniosynostosis
• For craniosynostosis, traditional surgery is performed after 6 months, but a minimally invasive procedure can be done earlier
• Follow-up treatment is not needed after traditional surgery but is required after minimally invasive surgery
• The craniofacial plastic surgeon will recommend the best course of action based on the individual patient's case