Helmet Therapy
What Is Infant Head Shape Difference (Deformational Plagiocephaly)?
A parent-friendly guide to deformational plagiocephaly: causes, signs, 3D evaluation, and when to seek advice for flat or asymmetric infant heads.
For new parents, every detail about their baby can feel miraculous. Sometimes, though, you may notice flattening at the back or side of the head. That can raise intense worries—“Is my baby’s brain being harmed?” or “Is this permanent?”
First, take a breath: you are not alone. Known in medical literature as deformational plagiocephaly, this pattern is common in infants and can often be managed when addressed at the right time. In this article, CranioWell explains what a head shape difference is and why it develops, with a practical clinical focus.
What Exactly Is Deformational Plagiocephaly?
Also called “flat head syndrome” or an asymmetric head, deformational plagiocephaly is asymmetric flattening at the back or side of the skull caused by external forces.
Infant cranial bones are not rigid like an adult’s. They are soft, flexible plates that have not yet fused, which helps with birth and early brain growth. That softness also means prolonged pressure in one position can change shape.
Important note: Plagiocephaly is not a disease of the brain itself. It is a surface shape difference of the skull. While it is generally not considered to block brain development directly, follow-up still matters.
Why Do Infant Head Shape Differences Occur?
The main cause is sustained pressure on soft cranial bones. Contributing factors include:
1. Sleep Position (Back Sleeping)
The “Back to Sleep” campaign that began in the 1990s substantially reduced Sudden Infant Death Syndrome (SIDS) risk and remains vital for infant safety. Continuous back sleeping has also increased how often flattening is seen at the back of the head.
2. Intrauterine Position and Multiple Pregnancy
Sometimes the shape difference starts before birth:
- A constrained position in the womb,
- Low amniotic fluid,
- Pressure between babies in twin or triplet pregnancies can contribute to asymmetry at birth.
3. Torticollis (Neck Tightness)
If neck muscles are short or tight (torticollis), the infant tends to look one way. Pressure then concentrates on one spot and that area can flatten.
4. Premature Birth
Premature infants often have softer cranial bones than term infants and may spend longer periods in fixed positions in hospital care, which can raise risk.
Signs of Plagiocephaly: What Should You Watch For?
Parents often notice this during baths or hair care. Possible signs include:
- Flattening: A clear flat area at the back or side of the head.
- Ear shift: The ear on the flatter side appearing farther forward than the other.
- Forehead prominence: Mild forward bulging of the forehead on the same side as the flattening.
- Facial asymmetry: In more advanced cases, cheek or eye-area asymmetry may be noticeable.
Diagnosis and Evaluation
If you suspect any of the signs above, consulting a clinician is the safest next step. At CranioWell and in healthcare settings, assessment usually begins with physical examination.
When needed, radiation-free light-based 3D scanning can measure asymmetry in millimeters. Those measurements help classify mild, moderate, or advanced severity and guide the care plan.
Frequently asked questions
Does an asymmetric infant head resolve on its own?
Mild differences may improve once the infant rolls and sits and pressure is reduced. In moderate and advanced deformation, waiting because “it will fix itself” can mean missing the most responsive treatment window. Specialist advice is recommended.
Does this affect my baby’s intelligence?
Deformational plagiocephaly is not a condition that stops brain development or causes intellectual disability. Severe cranial asymmetry has been discussed in relation to later jaw (temporomandibular) concerns or facial symmetry changes, so monitoring matters.
How long should I wait before seeing a doctor?
Do not wait—seek advice when you first notice a concern. The first 3–4 months are a period of rapid cranial shaping. Early steps (repositioning or, when indicated, helmet therapy fitted at CranioWell Orthotics & Prosthetics Centers) can support better outcomes.
Summary and Clinical Perspective
Infant head shape difference (plagiocephaly) is not a disease to fear; it is a process to manage. What matters is not losing time by assuming it will simply resolve, and acting with accurate information.
If asymmetry in your infant’s head shape worries you, CranioWell Orthotics & Prosthetics Center is here to help. Contact us for information about free pre-assessment and 3D scanning.
This content is for information only and does not replace medical diagnosis or treatment. Please consult your physician for definitive care decisions.