Babies typically have a soft skull. Which is to say an infant skull is made up of several separate plates connected by flexible ligaments known as sutures. This is to allow some flexibility for birth, to the allow the skull to develop as the brain grows.

These sutures retain some flexibility within the first two years, and as the child grows they fuse together to create a permanent skull shape that can not change. However, before the plates are fused together they are soft enough to be moulded by external pressure – like a child that spends the majority of its time lying down.

NKH kids typically have quite low tone. If they’re going to hold up their head, it’ll will be much later than neurotypical children. This means NKH kids are more likely to spend time lying down (in supine position).

That extra time and weight increases the developing a flat spot on their developing skull where they rest. The more time they spend on that spot, the more pronounced the skull shape will become.

Here is a video that talks about it:

There are few concerns with having a flat head – it’s not simply cosmetic.

• Because altering the shape of the skull can also alter the shape of the brain, there are some concerns around developmental delays, particularly on motor development.
• Uneven position of the ears (likely to cause ear infections in one ear)
• The eyes differ in size and position (one eye appears lower/smaller than the other)
• Mandibular asymmetry (misshaping of the jaw)
• Safety equipment for heads is typically designed for symmetrical heads (like bicycle helmets, for example)

Side note: Positional Plagiocephaly (PP) and Deformational Plagiocephaly (DP) both mean Plagiocephaly.

Study: Development in Toddlers with and without Deformational Plagiocephaly

• July 2009
• Study Source

Study Aim:  To determine whether the heightened risk of developmental delays seen in infants with deformational plagiocephaly (DP) continues into the toddler years.

Findings: It found that, on average, children with deformational plagiocephaly scored lower than those unaffected in all areas of the Bayley Scales of Infant and Toddler Development. The findings concluded that a higher level of developmental surveillance may be warranted with these children.

Study: Impact of Torticollis Associated With Plagiocephaly on Infants’ Motor Development

• Study Source
• Technology in Motion blog post.

Study Aim: To understand whether congenital or acquired torticollis can affect specific gross motor milestones of infants with plagiocephaly. It involved 175 infants that had plagiocephaly, some were affected and some unaffected by torticollis.

Findings: The presence or absence of congenital or acquired torticollis is an important factor that affects gross motor development in infants with plagiocephaly.

Study: Brain volume and shape in infants with deformational plagiocephaly

• June 2012
• Study Source

Study Aim: Infants with plagiocephaly have been shown to exhibit developmental delays relative to unaffected infants. Although the mechanisms accounting for these delays are unknown, one hypothesis focuses on underlying differences in brain development. In this study, MRI was used to examine brain volume and shape in infants with and without DP.

Findings: Infants show differences in brain shape that is consistent with skull deformity. Shape measures were also associated with infant development, however other studies are required to determine whether these developmental delays occur before or after the deformation.

Review of 5 Articles of “Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for the Patients with Positional Plagiocephaly” Articles in Neurosurgery 79: E623–E633

• 2016
• Journal Source
• Congress of Neurological Surgeons

Aim: This journal is designed to fill a gap for evidence-based guidelines for medical experts, offering information on how positional plagiocephaly should be diagnosed and treated. It is designed to be used across a range of specialities, including paediatricians, physical therapists and neurosurgeons.

• Repositioning
• Helmet