Your baby has a flat head (plagiocephaly, brachycephaly), or on the contrary, you want to avoid it?
As a new parent, you are likely discovering with concern all the issues that infants can face. And on the internet, there is often alarming or contradictory information…
My goal with this article?
To reassure you about this ultimately quite benign issue of a flat head.
And to answer all your questions: how to avoid it, what to do to treat it, when to worry, until what age it lasts, when the skull becomes round again, etc.
I am a pediatric and general physical therapist. I rely on my professional experience, but also on my research and readings in international scientific journals.
All the references to the publications I rely on are at the end of the article.
Happy reading 🙂!
Last update: November 2023
Disclaimer: no affiliate links. Complete disclosure in legal notices.
Written by Nelly Darbois, physical therapist and scientific writer
What is plagiocephaly / baby’s flat head?
First, let’s agree on what we mean by a flat head!
Flat head = plagiocephaly OR brachycephaly.
You will see that there are two forms of plagiocephaly / brachycephaly.
The most common is positional plagiocephaly. And the (much) rarer, due to craniosynostosis.
Positional Plagiocephaly & Brachycephaly
Infants can be affected by malformations or deformations in the skull. There are various degrees of skull deformation.
In the vast majority of cases, the deformation appears after birth. The baby most often presents a flattening of the back of the head:
- The flattening can be symmetrical: the head is flattened identically on both sides, this is called brachycephaly.
- When the flattening is asymmetrical, it is called plagiocephaly.
There is then one side of the back of the skull flatter than the other. The Plagiocephaly is said to be positional when it appears AFTER birth. In general, the deformation is noticed for the first time from 6 weeks of life (1 and a half months). Sometimes it is only noticed around 4 months (sometimes 6 months or 9 months).
This is why we talk about positional plagiocephaly (or brachycephaly): it does not appear in utero, in the mother’s belly. But afterward, due to the baby’s position, often on its back when sleeping.
Sometimes, we talk about mild, moderate, or severe plagiocephaly/brachycephaly. It depends on whether the deformation is very pronounced or not. Rest assured: even a severe form evolves well over time!
The Plagiocephaly on Craniosynostosis
There are other deformations of the skull, much rarer. They generally appear in utero and are related to premature fusion of different parts of the newborn’s skull. We then talk about plagiocephaly on craniosynostosis.
They are more serious and do not go unnoticed. They often require surgery.
In this article, I focus on positional plagiocephaly because it is by far the most common.
When to worry?
Some parents are afraid that their baby has craniosynostosis, not positional flat head. Here are some figures that should reassure you…
Frequency of craniosynostosis: 3 to 6 births per 10,000 (Cornelissen 2016)
Frequency of positional plagiocephaly or brachycephaly: 1 birth out of 4 (DiRocco 2019). Some figures even say up to 1 birth out of 2 (Ellwood 2020)!
So positional plagiocephaly is at least 2,500 births out of 10,000. There are therefore 625 times more chances that your baby has a flat head of positional origin than craniosynostosis! This figure and the reassuring words of the doctors you have already seen should reassure you :).
Whatever age you notice your baby’s flat head, there is no need to worry, to be afraid of having missed something. I advise you to simply follow the recommendations of the professionals who follow you, and preferably the most reassuring ones.
Also, know that the opinion without measuring the skull given by health professionals on the existence of plagiocephaly and its severity is of the same order as that given by people taking measurements. This means that it is not necessary to use special devices to measure a child’s skull: the eye is enough. (Kunz 2021)
What causes plagiocephaly?
The risk factors for a “flat head” are still poorly understood. In the literature dedicated to it, we find:
- being a boy; being the firstborn;
- the use of forceps or vacuum during childbirth;
- lying on the back to sleep. Indeed, the first studies on plagiocephaly / brachycephaly date back to the 1990s, when parents began to be recommended to make their baby sleep on their back rather than on their stomach;
- the presence of congenital torticollis or restricted head movements.
Several factors can explain why some children have plagiocephaly or brachycephaly, although we have difficulty identifying them. One thing is certain: it’s not your fault! However, you can do certain things to maximize the chances that things will return to normal quickly.
What are the consequences of plagiocephaly?
While looking for information on the consequences of plagiocephaly and brachycephaly, you may have come across a quite alarming list: ear infections, hearing impairments, visual disturbances, mental retardation, poorer learning at school… and the list goes on.
But remember the frequency figures for flat heads that I mentioned earlier: 1 in 4 or even 1 in 2 babies have this issue!
It is, therefore, very difficult to establish a causal link between these problems and plagiocephaly.
To date, there is no well-done study that demonstrates long-term negative consequences of positional plagiocephaly or brachycephaly.
Here is what a recent report from the French National Authority for Health (HAS) says about them:
Positional plagiocephalies – positional cranial deformities – are benign and naturally disappear around the age of two.HAS 2020
Note also that most websites highlighting serious consequences of plagiocephaly are sites selling things against plagiocephaly (often helmets, sometimes osteopathy or physiotherapy sessions).
How to avoid a flat head for your baby?
Here are things you can simply implement on your own.
All have one common point: limit the time your baby spends always in the same position in the same place, especially if it’s on the back.
Here are these tips:
During their child’s awake times, put them on their stomach often (tummy time).
This way, the back of the head will not be in contact with the ground. Flattening cannot be increased.
Vary their position (on their back, on their side, in a bouncer, in a suitable chair, carried in a baby carrier or sling, on your knees, etc.) and the type of surface (mattress on the floor, mattress in a playpen, bed, etc.)
If your baby seems to turn their head more often to one side than the other during their awake or resting times, adapt their environment to encourage them to look to the other side.
For example, if they often look to the left, position yourself to their right when you speak to them, place toys at a height to the right, lay them down with the light source to their right, feed them (spoon; bottle or breastfeeding) by positioning yourself to their right, etc.
Avoid leaving your baby in the same car seat for most of the day.
If you use a car seat for transportation, be sure to carry your baby in a baby carrier or sling when you get out of the car, or put them in a carrycot or a hammock stroller according to their age. This will vary the pressure points on their skull.
⚠️ In all cases, it is strongly recommended to let your baby sleep on their back. Indeed, the frequency of sudden infant death syndrome (SIDS) has significantly decreased since parents were encouraged to make their baby sleep on their back.
Studies have shown that there is indeed a causal link between putting babies to sleep on their backs and the decrease in the frequency of sudden infant death syndrome.
What is the treatment for plagiocephaly? What to do?
You may be wondering if the flat head corrects itself. How to correct, reshape a baby’s head? In other words:
Does plagiocephaly need treatment? And if so, how? Remember the quote from the French National Authority for Health that I mentioned earlier.
Therefore, to the question “Does the flat head need treatment?” I would answer: yes if it reassures you. But let’s not make parents feel guilty who do not particularly want to deal with it.
If you are one of those who want to actively address the flat head, I invite you to reread the tips I gave to avoid the flat head: these are exactly the same ones that need to be applied to maximize the chances that things will return to normal as best as possible!
Now, we will still go through different treatments often proposed against plagiocephaly. And I will give you my very frank opinion on each one.
Keeping in mind my 4 criteria for choosing one care over another:
- Maximum effectiveness (theoretical = in relation to our general knowledge of human physiology and biomechanics / empirical = studies);
- Minimum side effects;
- Minimum cost (in time, energy, money);
- Minimum dependence on a third party or equipment.
And to save you time, before detailing them, I give you an overview of the different plagiocephaly treatments scrutinized by these 4 criteria:
|Treatments||Theoretical Effectiveness||Side Effects||Empirical Effectiveness||Cost in Time/Energy/Money||Therapist Dependency||Equipment Dependency|
|Frequently changing baby’s position and environment 🥇||Yes||Theoretical side effects are low||?||Free||Simple||No|
|Specific exercises||Yes||Theoretical side effects are low||?||Yes||No||No|
|Physical Therapy||Yes||Theoretical side effects are low||?||Yes||Yes||No|
|Osteopathy||No||Theoretical side effects are low (if gentle maneuvers)||No||Yes||Yes||No|
Exercises for Plagiocephaly?
Your physical therapist, doctor, or osteopath can provide specific exercises to implement. These exercises will likely resemble the general advice I’ve given you, as there are limitations to what can be intentionally done with a few-month-old baby.
Are these exercises essential? Not in my opinion. Adhering to the general advice of changing your baby’s position and supporting them is already a very positive step.
It’s better to implement these general recommendations than to spend two minutes a day exercising your baby and then leaving them on their back in their car seat for most of the day!
Plagiocephaly & Physical therapy – Until What Age?
Physical therapy sessions may be prescribed, and in France, they are reimbursed by social security and health insurance.
Here’s how I proceed in such cases:
- I meet with the family and their baby for an assessment, asking questions and observing the child in their environment. I evaluate the parents’ level of concern, what they are already doing, and what other professionals have told them.
- I explain my view on plagiocephaly and its treatment, providing personalized advice. I suggest checking in after two weeks to see if they have implemented what we agreed upon. If they prefer more regular physiotherapy sessions, we can transition to a pediatric physiotherapy clinic (although parents have rarely chosen this option).
- I review the family two weeks later. Generally, things are going well, the family is reassured, and they manage to implement changes. We do not plan further appointments (unless requested by the family). I tell them to contact me if they have any concerns and wish them well with their baby!
This is the typical process, unless I detect other issues during the assessment (congenital torticollis, significant motor delays), in which case more “intensive” physiotherapy sessions may be necessary.
Until what age is this type of intervention suitable? I don’t think there is a specific age limit for at least having an assessment with a physiotherapist.
Depending on the child’s age (a few months or over a year), the subsequent intervention will be different. However, it is rare to see children over one year old for plagiocephaly or brachycephaly; generally, things are already starting to resolve on their own!
Plagiocephaly & Osteopathy
You might wonder if plagiocephaly can be “fixed” through manual manipulations by osteopaths.
To express my thoughts briefly and straightforwardly:
- The explanations given by osteopaths about the mechanism of action of these maneuvers do not hold up.
- No study has evaluated the effectiveness of osteopathic maneuvers on the evolution of babies’ skulls.
Some people may find reassurance in discussing their baby’s flat head issue with an additional interlocutor, especially an osteopath.
In my opinion, the cost (in time, possibly money) / potential benefits (reassurance) ratio is unfavorable. Therefore, I do not recommend osteopathy to parents of babies with a flat head.
Helmet for Plagiocephaly?
I have already written an extensive article on this: Should you make your baby wear a helmet for plagiocephaly or brachycephaly? (Also known as cranial orthosis: it’s the same thing.)
In summary: At 2 years old, whether babies with brachycephaly or plagiocephaly have worn a helmet or not, the shape of the skull is the same.
Anti-Flat Head Positioning Pillows?
No study has been conducted to evaluate their effectiveness.
National and international recommendations advise parents to place their child on a firm mattress (no memory foam mattresses for babies), without any cushion, to prevent the risk of sudden infant death syndrome.
I do not recommend anti-flat head pillows. It’s better to simply vary the baby’s positions, including in the crib!
The treatment of plagiocephaly or brachycephaly mainly involves advising parents on simple things they can do to limit the time their baby spends on their back during waking hours. And monitoring the gradual progression toward the disappearance of the flat head.
A synthesis of all studies on plagiocephaly treatments states:
Stretching and/or exercises, repositioning, and tummy time can be beneficial for some infants. Education, guidance, and support are likely to reassure and help parents.Ellwood 2020
How Long Does It Take to Regain a Rounded Skull?
In medicine, we study what is called the “natural course” of health issues—how they evolve over time, regardless of interventions. Alternatively, we try to examine whether individuals evolve differently based on the treatments they undergo or their lifestyle.
Good news: we have some data on this subject for infants’ and babies’ flat heads! Particularly from a study comparing the evolution of 5 to 6-month-old babies with severe or moderate positional plagiocephaly:
- Who wore a helmet for positional plagiocephaly.
- Who did not wear a helmet and did not receive any specific treatment.
These babies were followed for 2 years. What’s the assessment 2 years later? The shape of the skull is similar whether the babies wore a helmet or not.
Did they all regain a completely rounded skull? No. Three out of four children still have a less rounded skull than average. But the research team concludes:
One can always wonder what is an acceptable head shape in young infants and at an older age when the head is covered with hair.Van Wijk 2014
At least 1/4 of babies with brachycephaly or plagiocephaly (moderate or severe) regain a rounded skull by 2 years or earlier. Regardless of what they do.
Here’s what I wanted to tell you about this! IDo you have any comments or questions? Your comments are welcome 🙂 !
Watt A, Alabdulkarim A, Lee J, Gilardino M. Practical Review of the Cost of Diagnosis and Management of Positional Plagiocephaly. Plast Reconstr Surg Glob Open. 2022 May 16;10(5):e4328. doi: 10.1097/GOX.0000000000004328. PMID: 35702535; PMCID: PMC9187200.
Collett BR, Wallace ER, Ola C, Kartin D, Cunningham ML, Speltz ML. Do Infant Motor Skills Mediate the Association Between Positional Plagiocephaly/Brachycephaly and Cognition in School-Aged Children? Phys Ther. 2021 Feb 4;101(2):pzaa214. doi: 10.1093/ptj/pzaa214. PMID: 33340327; PMCID: PMC8525193.
Ellwood J, Draper-Rodi J, Carnes D. The effectiveness and safety of conservative interventions for positional plagiocephaly and congenital muscular torticollis: a synthesis of systematic reviews and guidance. Chiropr Man Therap. 2020 Jun 11;28(1):31. doi: 10.1186/s12998-020-00321-w. PMID: 32522230; PMCID: PMC7288527.
Linz et al. Positional Skull Deformities. Etiology, Prevention, Diagnosis, and Treatment. 2017. Dtsch Arztebl Int.
Van Wijk et al. Helmet therapy in infants with positional skull deformation: randomised controlled trial. 2014. BMJ
HAS (2020). Prévenir la plagiocéphalie sans augmenter le risque de mort inattendue du nourrisson
Khormi Y, Chiu M, Goodluck Tyndall R, Mortenson P, Smith D, Steinbok P. Safety and efficacy of independent allied healthcare professionals in the assessment and management of plagiocephaly patients. Childs Nerv Syst. 2020 Feb;36(2):373-377. doi: 10.1007/s00381-019-04400-z. Epub 2019 Nov 14. PMID: 31728704.
Cornelissen M, Ottelander Bd, Rizopoulos D, van der Hulst R, Mink van der Molen A, van der Horst C, Delye H, van Veelen ML, Bonsel G, Mathijssen I. Increase of prevalence of craniosynostosis. J Craniomaxillofac Surg. 2016 Sep;44(9):1273-9. doi: 10.1016/j.jcms.2016.07.007. Epub 2016 Jul 12. PMID: 27499511.
Di Rocco F, Ble V, Beuriat PA, Szathmari A, Lohkamp LN, Mottolese C. Prevalence and severity of positional plagiocephaly in children and adolescents. Acta Neurochir (Wien). 2019 Jun;161(6):1095-1098. doi: 10.1007/s00701-019-03924-2. Epub 2019 Apr 30. PMID: 31041593.
Written by Nelly Darbois
I love writing articles based on my experience as a physiotherapist (since 2012), scientific writer, and extensive researcher in international scientific literature.
I live in the French Alps 🌞❄️, where I work as a scientific editor for my own website, which is where you are right now.