Generality
Plagiocephaly is a "cranial abnormality typical of infants, characterized by a unilateral flattening of the occipito-parietal region of the cranial vault."
The causes of plagiocephaly are numerous; the most common is the prolonged unilateral resting of the head on the bed (or cradle), during the night or during daytime rests.
Diagnosis is fairly straightforward and is usually based on physical examination alone.
With some exceptions, plagiocephaly heals without special medical treatments, but only with simple precautions (vary the position of the child when he is awake; put him to sleep on a slightly inclined shelf, etc.).
Recalls of the anatomy of the human skull
Provided with bones and cartilages, the skull is the skeletal structure of the head that makes up the face and protects the brain, cerebellum, brainstem and sensory organs.
Contrary to what many people believe, its organization is very complex, perhaps among the most complicated in the human body. In fact, it has between 22 and 28 bones, which are even and uneven, have an irregular shape and are of the flat type (flat bones).
To simplify the study and understanding of the skull, anatomists thought of dividing it into two compartments, called neurocranium and splanchnocranium.
NEUROCRANIUM
The neurocranium is the upper cranial region, containing the brain and some of the main sensory organs. Its most important bones - strictly flat - are the frontal, temporal, parietal and occipital bones; these, together, form the so-called cranial vault. .
SPLANCNOCRANIUM
The splanchnocranium, or facial massif, is the antero-inferior region of the skull, made up of even and uneven bones. It represents the skeletal structure of the face, therefore it contains bone elements such as the mandible, the upper jaw, the cheekbones, the nasal bone, etc.
Figure: human skull. The main bones of the cranial vault and the neurocranium / splanchnocranium anatomical subdivision are shown (N.B: the red line ideally separates the neurocranium from the splanchnocranium).
DEVELOPMENT OF THE SKULL
At birth and during the first months of life, the cranial bones of newborns - especially those of the cranial vault - are easily modeled, as they are still soft, tender and not fused together.
As they grow, they merge in some strategic points (cranial sutures) and their consistency changes: they gradually become "stronger", less malleable and more resistant to shocks and constant pressure.
This process, which involves the progressive strengthening of the cranial bones, is part of the numerous mechanisms of ossification, affecting the human body.
What is plagiocephaly?
Plagiocephaly is a "morphological anomaly of the skull, typical of young children, characterized by a unilateral flattening of the occipito-parietal compartment of the cranial vault.
The one-sided deformation causes the head to present an asymmetry, such as to make it very similar to a rhomboid parallelogram.
If it is not of a high degree or with particularly serious causes, plagiocephaly is a condition that usually resolves without special treatment.
Figure: human skull. starting from the left, the photos show a child with a normal head (normocephaly), a case of mild plagiocephaly, a case of moderate plagiocephaly and a case of severe plagiocephaly.. From the site: www.cranialtech.com
ORIGIN OF THE NAME
The word plagiocephaly derives from the "union of two terms of Greek origin:" plagios "(πλάγιος‚), which means "oblique", and "chefale" (κεφαλή), which means "head".
Hence, the literal meaning of plagiocephaly is "oblique head".
PLAGIOCEPHALIA AND FLAT HEAD IN NEWBORN
Along with brachycephaly, plagiocephaly represents one of two causes of a more general condition, known as flat head in the newborn or flat head syndrome.
WHY DO IT HIT SMALL CHILDREN?
Plagiocephaly affects infants and very young children because the bones of the cranial vault are still soft and more easily modifiable (therefore malleable).
Causes
Plagiocephaly has several causes.
Currently, the most common is considered to be prolonged supine positioning of the baby, during the night and during daily naps. In fact, the supine position can involve the partial support of the back side of the head on the bed or on the cradle, in which the child sleeps. All this determines a not negligible pressure on the affected cranial region; malleability of the infant's cranial bones, this abnormal pressure can change the shape of the skull.
Plagiocephaly resulting from prolonged supine positioning is called postural plagiocephaly.
Attention: Reading the above, novice parents may find it wrong to put their child to sleep with their back against the bed.However, it should be noted that this is not the case at all: the supine position is correct and, unlike that on the side or on the stomach, it is not one of the factors favoring the so-called sudden infant death (SIDS).
OTHER POSSIBLE CAUSES
Other various causes of plagiocephaly include:
- Some problems of the uterus and intrauterine life.
According to some researches, the scarcity of amniotic fluid - a condition that takes the name of oligohydramnios - is responsible for morphological alterations of the head, including plagiocephaly and brachycephaly.
In particular, it would be decisive when the fetus, during labor, crosses the cervical canal of the uterus. - Premature birth.
In "crossing the cervical canal, children who are born prematurely have a greater tendency to undergo a morphological modification of the skull, as the malleability and softness of the cranial bones are even higher than in full-term births.
In this regard, readers are reminded that the last weeks of pregnancy are decisive for strengthening the cranial bones and making them resistant enough to avoid alterations during the crossing of the cervical canal. - Too weak neck muscles.
Children who, on one side of the neck, have too weak muscles, have a tendency to bend their head towards one side only, causing them to assume an incorrect position. All this would favor the flattening of only one side of the head. - Craniosynostosis.
Craniosynostosis is the term with which doctors refer to an "anomaly of the skull, due to the premature fusion of one or more cranial sutures.
The form of craniosynostosis responsible for plagiocephaly is that which involves the lambdoid suture, located between the parietal bones and the occipital bone, in the back of the head.
As will be seen in the chapter dedicated to therapy, the craniosynostosis of the lambdoid suture always requires surgical treatment and this distinguishes plagiocephaly due to this cause (i.e. the premature fusion of the aforementioned suture) from that due to one of the previous causes.
EPIDEMIOLOGY
Plagiocephaly is now much more common than it used to be, due to a substantial increase in cases of postural plagiocephaly.
According to some statistics, they would suffer from postural plagiocephaly:
- 16% of 6-week-old babies
- 20% of 4-month-old babies
- 7% of 12-month-old babies
- 3% of 24-month-old babies
Symptoms and Complications
The clinical sign that characterizes every case of plagiocephaly is the unilateral flattening of the back of the head.
To this typical manifestation, other anomalies can sometimes be added, such as:
- One ear in a more advanced position than the other (N.B: this can be found by observing the child from above).
- One eye smaller than the other.
- One cheek more swollen than the other.
WHAT DOES THE LOCATION OF THE FLAPING DEPEND ON?
The precise location of the flattening depends on the causes.
For example, in the case of postural plagiocephaly, the anomaly resides on the side of the head that the child has the habit of placing more often on the bed; while, in the presence of a weak neck muscles, the flattening of the head results on the opposite side to that where the muscles are weak (and towards which the infant tends to bend the head).
COMPLICATIONS
In general, plagiocephaly represents a drawback only from an aesthetic point of view; an inconvenience, among other things, almost always temporary.
It is very rare that it involves complications: when present, these are often associated with the presence of craniosynostosis, a very uncommon condition, which affects one in every 1,800-3,000 newborns.
Diagnosis
In general, a physical examination is sufficient to diagnose plagiocephaly and its particularities.
In medicine, physical examination means the physician's evaluation of the symptoms and signs present and / or reported by the patient.
The use of more specific diagnostic tests - in this case instrumental tests such as X-rays or CT - occurs only in the presence of doubts regarding the causes: where there is suspicion of a craniosynostosis, the treating doctor has the duty to investigate the situation thoroughly , to understand how to act from a therapeutic point of view.
Treatment
The treatment adopted varies according to the severity of the plagiocephaly.
In case of slight flattening, the anomaly generally heals without special care; in these cases it is sufficient to put into practice (by the parents) some simple measures, the common purpose of which is to reduce the pressure on the occipital area of the skull.
In the case of more marked flattening, the aforementioned measures are still useful, however they may not be enough to achieve healing. In fact, in these situations, it is probable that the remodeling of the head is only partial, therefore the morphological anomaly can leave signs of its passage.
Finally, the cases of plagiocephaly sustained by weakness of the neck muscles and craniosynostosis deserve a separate mention: each of these requires specific medical treatment, the failure of which tends to have permanent repercussions.
SIMPLE REMEDIES TO REDUCE THE PRESSURE ON THE HEAD
The measures, which allow to reduce the pressure on the back of the head, are:
- When the baby is awake,
- Make him assume positions where he does not rest the back of his head on the shelf on which he is located. A valid solution is to lay him on his stomach (i.e. prone), taking care to always keep him awake and stay with him for as long as he remains in this position. These precautions are explained by the link, already mentioned above, between the prone position during sleep and the sudden death of the infant.
- When the baby sleeps,
- Avoid always positioning it with the head turned to one side only. In other words, often vary its position, so that there is no particular area of the head subjected to greater pressures than others.
If this recommendation is difficult to implement, it is best to put the baby to sleep on a slightly inclined or flat shelf. - When the child plays,
- Often change the position of the toys that attract her attention the most. This can be a way to make him dizzy even when he's lying on his crib or bed.
- When you are traveling with your baby or taking him for a walk,
- Provide for the use of seats and strollers that do not involve excessive pressure on the back of the head.
Also in this case, it is essential to avoid that the child always keeps his head facing the usual side.
A particularly valid remedy is to use baby wraps or backpacks, which allow the parent to hold the baby in front of him, without the latter resting his head on some shelf.
To see the first results of these important measures, parents may have to wait 6 to 8 weeks.
WHEN THE NECK MUSCLES ARE WEAK
When plagiocephaly is associated with weak neck muscles, doctors recommend physiotherapy to parents.
There are, in fact, particular physiotherapy exercises that guarantee a strengthening of the neck and the possibility of turning the head on both sides.
By allowing the patient to tilt the head both to the right and to the left, the pressure on an exclusive area of the head is considerably reduced; moreover, at this point, it is also possible to implement the measures described above.
Prompt use of physiotherapy increases the chances of complete recovery.
IN THE PRESENCE OF CRANIOSYNOSTOSIS
Plagiocephaly due to craniosynostosis requires surgery ad hoc, aimed at separating the cranial sutures fusing prematurely with each other.
To know the characteristics of the operation, the reader can rely on what is reported in the article present here.
USE OF HELMETS: ARE THEY EFFECTIVE?
In some countries of the world, doctors use cranial orthoses, similar to helmets, with the aim of protecting the head from any pressure and favoring the correction of morphological abnormalities such as plagiocephaly or brachycephaly.
Especially in recent years, the use of these corrective tools has raised some doubts. Several experts, in fact, believe that cranial orthoses produce limited improvements, especially when compared with the aforementioned measures.
Furthermore, they advise against its use for two other reasons: they are expensive (and not all families could afford them) and very uncomfortable for the child.
Prognosis
With the appropriate precautions, mild plagiocephaly forms heal completely between the first and second year of life.
