What types of head shape deformities are seen in infants?
Deformational plagiocephaly (Often known as flat head syndrome) is an abnormal shape of a baby's head caused by external forces. The baby's head may appear to be misshapen or asymmetrical immediately after birth, or the abnormal shape may become noticeable n the first few months of life. Parents and carers are often the first ones to notice the unusual shape of the head and usually bring it to the attention of the GP or health visitor during a regular check up. Head shape abnormalities are usually more noticeable at bath time when a baby's hair is wet and in babies with little hair.
Deformational brachycephaly is when the entire back of the baby's head is flat (central flattening) and the head is very wide. The forehead is often bossed or prominent on both sides, and the height of the head is very high. Often, babies with this problem have a history of excessive time in carriers and car seats, or suffer from medical conditions that do not allow the baby to be placed on the tummy. Treatment through orthotic management attempts to correct the disproportation of the head shape and the associated deformities.
Asymmetrical brachycephaly is a common type of brachycephaly where the head is excessively wide and is also asymmetrical. Treatment through orthotic management focuses on improving both symmetry and the proportions of the baby's head.
Deformational scaphocephaly is characterized by a long and narrow head shape, sometimes caused by consistent positioning of the baby on his or her side. Like symmetrical brachycephaly, scaphocephaly is mainly a deformity of proportion, although the elongated shape can also produce abnormal frontal and posterior changes in the head.
Premature babies are particularly preceded to scaphocephaly, because a side-lying position is often used in the neonatal intensive care unit (NICU) for easy access to monitors and other equipment. Treatment through orthotic management focuses on normalizing the proportion and overall shape of the head.
Craniosynostosis is caused by the suture between the plates of the baby's head fusing together prematurely, and can occur at any of the sutures between the 5 plates of the baby's skull. The area that has fused does not grow at the same rate as the rest of the skull which can cause pressure to the brain. This is a rare condition affecting only 1 in 2500-3000 births. Treatment of craniosynostosis is surgery to remove the section of fused skull and allow normal development. This is usually performed by a neurosurgeon or a craniofacial surgeon.
What causes deformational plagiocephaly?
There are several causes of deformational plagiocephaly, and some of them occur before the baby is born. Restricted space inside the mother's womb can create excess contact in certain areas of the baby's head. This is often the cause of deformation in infants positioned in a breach position, cramped in utero due to multiple foetuses, or in babies who spend excessive time with the head confined in the birth canal. Suction or vacuum instruments can also create forces that can deform the newborn skull, which is soft and pliable. After birth, the skulls of premature babies are particularly susceptible to deformation because they are thinner and more fragile than those of full term babies.
The skull is made up of several plates with fibrous sutures between them. This allows the skull plates to slide over each other to ease the passage of the baby's head through the birth canal. Usually, the head becomes more symmetrical and better proportioned within 6 weeks of birth if the deforming forces are no longer present. However, the flattened area may not resolve if the baby's head continues rests in the same position. This is particularly problematic if the baby has neck tightness at birth (torticollis).
Are there other causes of head shape deformities?
Another leading cause of abnormal head shape in young babies is neck tightness caused by congenital muscular torticollis or neck trunk muscle imbalance. Torticollis is usually caused by an imbalance in the sternocleidomastoid and other neck muscles, which results in the full range of motion in the neck. It is estimated that about 85% of the babies with deformational plagiocephaly also have some kind of neck issue.
Typically, the head of the baby with torticollis is tipped to one side and rotated to the opposite shoulder, causing the head to consistently rest in the same position. This constant pressure to the same side of the head causes flattening. Torticollis can also pull abnormally on the base of the skull and cause the ear on the same side of the flattening to be pushed forward. In severe cases, the forehead can also be pushed forward on the same side, the facial features including the eyes, cheeks, and the jaw may not be symmetrical.
Another postnatal cause of abnormal head shapes occurs when the back of the baby's head rests for prolonged periods of time against a hard surface like a car seat, bouncy chair, swing or push chair.
Before 1996, babies were put to sleep on their tummies, which varied the amount of force on the back of the head. Since the "reduce the risk" advice from the FSID (Foundation for the Study of Infants Death) as an effort to end the sudden infant death syndrome (SIDS), babies now spend all night on their backs until they are able to roll and reposition themselves.Unfortunately, the combination of the equipment we use to carry and position our babies during the day and placing them to sleep on their backs all night has led to an increase in head shape deformities. It is very encouraging that the incidence of SIDS has reduced by 40% following the introduction of "back to bed".
The best way to reduce the potential for the head shape problems is to increase the time your baby spends on his or her tummy during the day while wake and supervised.